70 results on '"Matamala JM"'
Search Results
2. Prevalence of body dysmorphic disorder in Chilean dermatological patients
- Author
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Calderón, P, primary, Zemelman, V, additional, Sanhueza, P, additional, Castrillón, MA, additional, Matamala, JM, additional, and Szot, J, additional
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- 2009
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3. Diagnostic utility of transcranial magnetic stimulation for neurodegenerative disease: a critical review.
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Moreno-Roco J, Del Valle L, Jiménez D, Acosta I, Castillo JL, Dharmadasa T, Kiernan MC, and Matamala JM
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Neurodegenerative diseases pose significant challenges due to their impact on brain structure, function, and cognition. As life expectancy rises, the prevalence of these disorders is rapidly increasing, resulting in substantial personal, familial, and societal burdens. Efforts have been made to optimize the diagnostic and therapeutic processes, primarily focusing on clinical, cognitive, and imaging characterization. However, the emergence of non-invasive brain stimulation techniques, specifically transcranial magnetic stimulation (TMS), offers unique functional insights and diagnostic potential. TMS allows direct evaluation of brain function, providing valuable information inaccessible through other methods. This review aims to summarize the current and potential diagnostic utility of TMS in investigating neurodegenerative diseases, highlighting its relevance to the field of cognitive neuroscience. The findings presented herein contribute to the growing body of research focused on improving our understanding and management of these debilitating conditions, particularly in regions with limited resources and a pressing need for innovative approaches., Competing Interests: Disclosure: The authors report no conflicts of interest.
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- 2024
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4. Pain-Related Vertex Evoked Potentials. Comparison of Surface Electrical to Heat Stimulation.
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Guiloff RJ, Campero M, Barraza GR, Treede RD, Matamala JM, and Castillo JL
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- Humans, Evoked Potentials, Somatosensory physiology, Evoked Potentials, Skin innervation, Skin pathology, Electric Stimulation, Hot Temperature, Neuralgia
- Abstract
Introduction: Demonstration of nociceptive fiber abnormality is important for diagnosing neuropathic pain and small fiber neuropathies. This is usually assessed by brief heat pulses using lasers, contact heat, or special electrodes. We hypothesized that pain-related evoked potentials to conventional surface electrical stimulation (PREPse) can index Aδ afferences despite tactile Aß fibers coactivation. PREPse may be more readily used clinically than contact heat evoked potentials (CHEPS)., Methods: Twenty-eight healthy subjects. Vertex (Cz-A1/A2) recordings. Electrical stimulation of middle finger and second toe with conventional ring, and forearm/leg skin with cup, electrodes. Contact heat stimulation to forearm and leg. Compression ischemic nerve blockade., Results: PREPse peripheral velocities were within the midrange of Aδ fibers. N1-P1 amplitude increased with pain numerical rating scale graded (0-10) electrical stimulation (n = 25) and decreased with increasing stimulation frequency. Amplitudes were unchanged by different presentation orders of four stimulation intensities. PREPse N1 (∼130 milliseconds) and N2 (∼345 milliseconds) peaks were approximately 40 milliseconds earlier than that with CHEPS. PREPse and CHEPS N1-N2 interpeak latency (∼207 milliseconds) were similar. PREPse became unrecordable with nerve blockade of Aδ fibers., Conclusions: PREPse earlier N1 and N2 peaks, and similar interpeak N1-N2 latencies and central conduction velocities, or synaptic delays, to CHEPS are consistent with direct stimulation of Aδ fibers. The relation of vertex PREPse amplitude and pain, or the differential effects of frequency stimulation, is similar to pain-related evoked potential to laser, special electrodes, or contact heat stimulation. The relationship to Aδ was validated by conduction velocity and nerve block. Clinical utility of PREPse compared with CHEPS needs validation in somatosensory pathways lesions., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2022 by the American Clinical Neurophysiology Society.)
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- 2023
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5. Teaching NeuroImage: Radial Compression Neuropathy Secondary to Accessory Belly of the Triceps Muscle.
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Bastias P, Melo R, Matamala JM, Earle N, and Acosta I
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- Humans, Muscle, Skeletal diagnostic imaging, Radial Nerve, Arthrogryposis, Nerve Compression Syndromes diagnostic imaging, Nerve Compression Syndromes etiology, Nerve Compression Syndromes surgery, Hereditary Sensory and Motor Neuropathy, Radial Neuropathy diagnostic imaging, Radial Neuropathy etiology
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- 2023
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6. Strength-duration properties and excitability of motor and sensory axons across different target thresholds.
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Shimatani Y, Lin CS, Matamala JM, and Kiernan MC
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- Humans, Action Potentials physiology, Axons physiology, Sensory Thresholds physiology, Motor Neurons physiology, Peripheral Nervous System Diseases
- Abstract
The present series of studies aimed to investigate the biophysical basis underlying differences in behavior between motor and sensory axons at different target response levels. In 24 healthy individuals, axonal excitability protocols measured strength-duration properties and latent addition across several axonal populations, with target amplitudes set at 10%, 20%, 40%, and 60%. Strength-duration time constants (SDTCs) were typically longer at lower target levels for both motor and sensory axons. Threshold change at 0.2 ms during assessment of latent addition, representing a persistent Na
+ current (Nap ), was higher in sensory axons. Passive membrane properties were not different across target levels. Significant relationships were evident between the threshold change at 0.2 ms and SDTC across all target levels for motor and sensory axons. These differences were explored using mathematical modeling of excitability data. With decreasing target size, as the internodal leak conductance increased in sensory axons, the Barrett-Barrett conductance decreased, whereas the hyperpolarization-activated cation current ( Ih ) channels became more depolarized. A similar pattern was observed in motor axons. As such, it was concluded that Nap was not responsible for the differences observed in SDTC between different target levels, although within specific target levels, Nap changes contributed to the variability of SDTC. This study provides a comprehensive assessment of Nap current, SDTC, and outlines key factors operating at different target levels in motor and sensory axons. Findings from the present study may point to the contributing factors of symptom development in human neuropathy. NEW & NOTEWORTHY This study provides a comprehensive assessment concerning the strength-duration behavior of motor and sensory axons at differing target levels of the compound nerve response. Strength-duration time constant was increased at lower target response levels particularly for sensory axons, whereas threshold change at 0.2 ms and passive membrane properties were not different. The results have established templates for axonal behavior in normal human axons, demonstrating altered adaptive responses, presumably secondary to different patterns of nerve activation.- Published
- 2023
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7. [Multidisciplinary care and therapeutic advances in amyotrophic lateral sclerosis].
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Matamala JM, Moreno-Roco J, Acosta I, Hughes R, Lillo P, Casar JC, and Earle N
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- Humans, Quality of Life, Palliative Care, Disease Progression, Amyotrophic Lateral Sclerosis therapy, Amyotrophic Lateral Sclerosis diagnosis, Amyotrophic Lateral Sclerosis psychology, Neurodegenerative Diseases
- Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that mainly affects the motor system, resulting in progressive weakness and muscle wasting. Despite the tremendous advances in physiopathological and clinical characterization, we do not have a curative treatment yet. The progressive and fatal course of ALS makes its management particularly complex and challenging given the diversity of symptoms presenting during the disease progression. The main goal in the treatment of ALS patients is to minimize morbidity and maximize the quality of life. Currently, a series of therapeutic interventions improve the quality of life and prolong survival, including multidisciplinary care, respiratory management, and disease-modifying therapy. Within the supportive interventions, weight maintenance through nutritional and metabolic support is critical. In addition, the management of neuropsychiatric manifestations and preservation of communicative capacity before speech loss are also crucial. Lastly, early palliative care intervention is essential to optimize symptomatic management. Anticipatory guidelines to face the inevitable patient deterioration should be devised. This article updates the main therapeutic strategies used in these patients, including evolving clinical trials with promising novel therapies.
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- 2022
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8. [Late-onset hereditary transthyretin amyloidosis with polyneuropathy. Report of one case].
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Matamala JM, Peña C, Moreno-Roco J, Álvarez J, Villegas P, Stuardo A, Puga B, Valjalo R, Correa G, Jeraldo C, Méndez G, Larrondo J, Gosch M, and Carrasco R
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- Humans, Female, Aged, Prealbumin genetics, Mutation, Amyloid Neuropathies, Familial complications, Amyloid Neuropathies, Familial diagnosis, Amyloid Neuropathies, Familial genetics, Polyneuropathies etiology, Polyneuropathies genetics
- Abstract
Hereditary transthyretin amyloidosis is a multisystemic autosomal dominant genetic disorder characterized by progressive distal sensory-motor polyneuropathy or restrictive cardiomyopathy, secondary to amyloid deposits. Its pathogenesis lies in the TTR gene mutation, and the Val50Met mutation is the most frequent. Patients have significant differences in the onset and severity of clinical presentation according to their country of origin. The diagnosis of this pathology is complex, even more in countries where it is not considered endemic. However, early suspicion and management are essential to improve survival and avoid unnecessary diagnostic and therapeutic strategies. We report a 69-year-old woman who presented a sensory-motor polyneuropathy, predominantly sensory, associated with distal neuropathic pain and bilateral vitritis. The history of her Italian father with polyneuropathy of unspecified etiology stood out. A vitreous biopsy identified amyloid substance deposits (congo red positive). These were also confirmed on a superficial peroneal nerve biopsy. During the etiological study of her polyneuropathy, an increased Kappa/Lambda index of 2.55 mg/L stood out. Therefore, light chain amyloidosis was suspected, and chemotherapy treatment was indicated without favorable response. After 10 years of progressive neurological and ophthalmological involvement, a genetic study confirmed the first case of late-onset hereditary transthyretin amyloidosis Val50Met with polyneuropathy in Chile.
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- 2022
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9. Review of techniques useful for the assessment of sensory small fiber neuropathies: Report from an IFCN expert group.
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Verdugo RJ, Matamala JM, Inui K, Kakigi R, Valls-Solé J, Hansson P, Nilsen KB, Lombardi R, Lauria G, Petropoulos IN, Malik RA, Treede RD, Baumgärtner U, Jara PA, and Campero M
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- Evoked Potentials, Humans, Nerve Fibers, Unmyelinated, Pain, Skin innervation, Peripheral Nervous System Diseases diagnosis, Small Fiber Neuropathy diagnosis
- Abstract
Nerve conduction studies (NCS) are an essential aspect of the assessment of patients with peripheral neuropathies. However, conventional NCS do not reflect activation of small afferent fibers, including Aδ and C fibers. A definitive gold standard for laboratory evaluation of these fibers is still needed and therefore, clinical evaluation remains fundamental in patients with small fiber neuropathies (SFN). Several clinical and research techniques have been developed for the assessment of small fiber function, such as (i) microneurography, (ii) laser evoked potentials, (iii) contact heat evoked potentials, (iv) pain-related electrically evoked potentials, (v) quantitative thermal sensory testing, (vi) skin biopsy-intraepidermal nerve fiber density and (vii) corneal confocal microscopy. The first five are physiological techniques, while the last two are morphological. They all have advantages and limitations, but the combined use of an appropriate selection of each of them would lead to gathering invaluable information for the diagnosis of SFN. In this review, we present an update on techniques available for the study of small afferent fibers and their clinical applicability. A summary of the anatomy and important physiological aspects of these pathways, and the clinical manifestations of their dysfunction is also included, in order to have a minimal common background., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)
- Published
- 2022
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10. Education and training in clinical neurophysiology: Actual state and future needs.
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Verdugo RJ and Matamala JM
- Abstract
Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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- 2022
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11. [Degenerative cervical myelopathy].
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Yurac R, Matamala JM, Zamorano JJ, Harrop JS, Davies BM, Nouri A, and Fehlings MG
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- Adult, Cervical Vertebrae diagnostic imaging, Cervical Vertebrae pathology, Disease Progression, Humans, Magnetic Resonance Imaging, Spinal Cord Compression diagnosis, Spinal Cord Compression etiology, Spinal Cord Compression therapy, Spinal Cord Diseases diagnostic imaging, Spinal Cord Diseases therapy
- Abstract
Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction in adults. Its prevalence is increasing as a result of population aging. The diagnosis of DCM is often delayed or overlooked, resulting in secondary neurologic morbidity. The natural course of DCM typically presents as a gradual neurological deterioration, with symptoms ranging from muscle weakness to complete paralysis, with variable degrees of sensory deficits and sphincter dysfunction. Magnetic resonance imaging (MRI) and electrophysiological studies allow the assessment of spinal cord function and its structural damage to determine treatment and clinical outcomes. All patients with signs and symptoms consistent with DCM should be referred to a spine surgeon for assessment and tailored treatment. Those patients with mild DCM can be managed non-operatively but require close monitoring and education about potentially alarming signs and symptoms. Surgery is not currently recommended for asymptomatic patients with evidence of spinal cord compression or cervical spinal stenosis on MRI, but they require a structured follow-up. Patients with moderate or severe DCM require surgical decompression to avoid further progression. The objective of this review is to raise awareness of degenerative cervical myelopathy and its increasing prevalence as well as to aid non-surgical healthcare workers for a timely diagnosis and management of this disabling condition.
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- 2022
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12. [Fasciculations and cramps: physiological bases and clinical approach of a complex phenomenon].
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Acosta I, Bastías P, and Matamala JM
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- Electromyography adverse effects, Humans, Motor Neurons physiology, Muscle Cramp diagnosis, Muscle Cramp etiology, Muscle Cramp therapy, Amyotrophic Lateral Sclerosis complications, Amyotrophic Lateral Sclerosis diagnosis, Amyotrophic Lateral Sclerosis therapy, Fasciculation diagnosis, Fasciculation etiology, Fasciculation therapy
- Abstract
Fasciculations and cramps originate in the motor unit, a functional unit that includes the lower motor neuron and their innervated muscle fibres. Both are common complaints in outpatient practice. These symptoms can be secondary to neurological or medical pathology, presenting a broad differential diagnosis and a complex approach. Recent neurophysiological studies have increased the knowledge of their origin mainly in amyotrophic lateral sclerosis. The symptomatic management of fasciculations and cramps depends on their etiology and includes pharmacological and non-pharmacological treatments. This article aims to present an updated review of the most relevant aspects of physiopathology, clinical approach, and differential diagnosis of both phenomena.
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- 2021
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13. [Quantitative electroencephalogram for prediction of delayed ischemia in subarachnoid haemorrhage. Report of one case].
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Castillo JL, Reyes S P, Gutiérrez R, Matamala JM, Segovia L, Menendez P, Torres C, Cid R, Bustamante G, and Feuerhake W
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- Aged, Cerebral Infarction, Electroencephalography adverse effects, Electroencephalography methods, Female, Humans, Retrospective Studies, Brain Ischemia diagnostic imaging, Brain Ischemia etiology, Subarachnoid Hemorrhage complications, Subarachnoid Hemorrhage diagnostic imaging
- Abstract
Subarachnoid hemorrhage (SAH) is a devastating disease, with a mortality rate of 35%. Among patients who survive the initial bleeding, the leading cause of morbidity and mortality is delayed cerebral ischemia (DCI). Electroencephalography (EEG) can detect cerebral ischemia in the early stages. We report a 66-year-old female patient who consulted for ictal headache and impaired consciousness. On admission, she was confused, dysarthric, and with meningeal signs. Brain angio-CT showed SAH FISHER IV and an aneurysm of the left posterior cerebral artery. After excluding the aneurysm (by coiling), the patient recovered the altered consciousness. Continuous EEG monitoring was initiated. On the sixth day of follow up, she had a transient headache and apathy. The brain MRI showed low cerebral blood flow in the left frontotemporal area, without ischemic lesions. On the seventh day, she presented expression aphasia and right facial-brachial paresis. Angiography confirmed severe vasospasm in M1 and M2 segments bilaterally. Pharmacological angioplasty with nimodipine was performed, with an excellent radiological response, although not clinical. A second MRI was carried out on the eighth day, which showed a left insular infarction and generalized vasospasm. A second therapeutic angiography was performed; the patient persisted with aphasia and left central facial paresis. The quantitative EEG analysis performed retrospectively showed a generalized reduction in the spectral edge frequency 95 (SEF95; meaning slowing in the EEG signal) at the fourth day of follow up, three days earlier than the clinical and imaging diagnosis of DCI was established.
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- 2021
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14. Effect of racial background on motor cortical function as measured by threshold tracking transcranial magnetic stimulation.
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Suzuki YI, Ma Y, Shibuya K, Misawa S, Suichi T, Tsuneyama A, Nakamura K, Matamala JM, Dharmadasa T, Vucic S, Fan D, Kiernan MC, and Kuwabara S
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- Adult, Amyotrophic Lateral Sclerosis physiopathology, Arm physiology, Asian People, Female, Humans, Male, Middle Aged, Peripheral Nerves physiology, White People, Amyotrophic Lateral Sclerosis ethnology, Evoked Potentials, Motor, Motor Cortex physiology, Transcranial Magnetic Stimulation standards
- Abstract
A previous study using traditional paired-pulse TMS methods (amplitude-tracking) has reported differences in resting motor threshold (RMT) and short-interval intracortical inhibition (SICI) between healthy subjects of Caucasian and Han Chinese backgrounds, probably due to differences in the skull shape. The amplitude-tracking method delivers stimuli with constant intensity and causes substantial variabilities in motor-evoked potential amplitudes. To overcome this variability, threshold tracking transcranial magnetic stimulation (TT-TMS) has been developed. The present study aimed to investigate whether racial differences in motor cortical function exist, using TT-TMS. A total of 83 healthy volunteers (30 Caucasians, 25 Han Chinese, and 28 Japanese) were included in the present series. In TT-TMS and nerve conduction studies, electrodes were placed on the dominant limb, with measures recorded from the abductor pollicis brevis muscle. Stimulations were delivered with a circular coil, directly above the primary motor cortex. There were no significant differences at all the SICI intervals between races. Similarly, there were no significant differences in other measures of excitability including mean RMT, intracortical facilitation, and cortical silent period. Contrary to traditional amplitude-tracking TMS, motor cortical excitability and thereby motor cortical function is minimally influenced by racial differences when measured by TT-TMS. Recent studies have disclosed that SICI measured by TT-TMS differentiates amyotrophic lateral sclerosis (ALS) from ALS mimic disorders, with high sensitivity and specificity, in Caucasians. This study suggested that TT-TMS can be applied for the ALS diagnosis in Asian patients, as well as Caucasians. NEW & NOTEWORTHY Threshold tracking transcranial magnetic stimulation (TT-TMS) was applied for Caucasians, Han Chinese, and Japanese. No significant differences were found in TMS excitability indexes among races. Recent studies have disclosed that TT-TMS indexes differentiate amyotrophic lateral sclerosis (ALS) from ALS mimic disorders, with high sensitivity and specificity, in Caucasians. This study suggested that TT-TMS can be applied for the ALS diagnosis in Asian patients, as well as Caucasians.
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- 2021
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15. [Subacute encephalopathy associated with relapsing polychondritis. Report of one case].
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Vera C, Matamala JM, Feuerhake W, Neira O, Vidal A, and Castillo JL
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- Adrenal Cortex Hormones, Adult, Brain diagnostic imaging, Female, Humans, Magnetic Resonance Imaging, Brain Diseases etiology, Polychondritis, Relapsing complications, Polychondritis, Relapsing diagnosis, Polychondritis, Relapsing drug therapy
- Abstract
Relapsing polychondritis (RP) is a rare multisystemic autoimmune disorder characterized by the inflammation and destruction of cartilages, with preference for auricular, nasal and laryngotracheal cartilages. RP may also affect proteoglycan-rich structures, such as, blood vessels, eyes, kidneys, and heart. The central nervous system (CNS) is involved in less than 3% of patients. We report a 32-year-old female with RP associated with a progressive subacute encephalopathy characterized by behavioral disturbances, auditory and visual hallucinations. The EEG showed generalized slow activity and a mononuclear pleocytosis with increased protein was found in the cerebrospinal fluid. The brain magnetic resonance imaging showed multiple supra and infratentorial nodular inflammatory lesions. After initiating treatment with corticosteroids and cyclophosphamide, a significant improvement in chondritis and neurological status was observed.
- Published
- 2021
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16. Evaluation of autonomic function: Standards needed are now available.
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Verdugo RJ and Matamala JM
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- Autonomic Nervous System, Humans, Autonomic Nervous System Diseases
- Abstract
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
- Published
- 2021
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17. Motor cortical excitability predicts cognitive phenotypes in amyotrophic lateral sclerosis.
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Agarwal S, Highton-Williamson E, Caga J, Howells J, Dharmadasa T, Matamala JM, Ma Y, Shibuya K, Hodges JR, Ahmed RM, Vucic S, and Kiernan MC
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- Aged, Behavior, Female, Humans, Male, Middle Aged, Phenotype, ROC Curve, Transcranial Magnetic Stimulation, Amyotrophic Lateral Sclerosis physiopathology, Cognition physiology, Cortical Excitability physiology, Motor Cortex physiopathology
- Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are well-recognised as an extended disease spectrum. This study hypothesised that cortical hyperexcitability, an early pathophysiological abnormality in ALS, would distinguish cognitive phenotypes, as a surrogate marker of pathological disease burden. 61 patients with ALS, matched for disease duration (pure motor ALS, n = 39; ALS with coexistent FTD, ALS-FTD, n = 12; ALS with cognitive/behavioural abnormalities not meeting FTD criteria, ALS-Cog, n = 10) and 30 age-matched healthy controls. Cognitive function on the Addenbrooke's cognitive examination (ACE) scale, behavioural function on the motor neuron disease behavior scale (MiND-B) and cortical excitability using transcranial magnetic stimulation (TMS) were documented. Cortical resting motor threshold (RMT), lower threshold indicating hyperexcitability, was lower in ALS-FTD (50.2 ± 6.9) compared to controls (64.3 ± 12.6, p < 0.005), while ALS-Cog (63.3 ± 12.7) and ALS (60.8 ± 13.9, not significant) were similar to controls. Short interval intracortical inhibition (SICI) was reduced across all ALS groups compared to controls, indicating hyperexcitability. On receiver operating characteristic curve analysis, RMT differentiated ALS-FTD from ALS (area under the curve AUC = 0.745, p = 0.011). The present study has identified a distinct pattern of cortical excitability across cognitive phenotypes in ALS. As such, assessment of cortical physiology may provide more precise clinical prognostication in ALS.
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- 2021
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18. Cortical inexcitability defines an adverse clinical profile in amyotrophic lateral sclerosis.
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Dharmadasa T, Howells J, Matamala JM, Simon NG, Burke D, Vucic S, and Kiernan MC
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- Evoked Potentials, Motor, Humans, Lower Extremity, Transcranial Magnetic Stimulation, Amyotrophic Lateral Sclerosis, Motor Cortex
- Abstract
Background and Purpose: In amyotrophic lateral sclerosis, studies using threshold-tracking transcranial magnetic stimulation (TMS) have identified corticomotoneuronal dysfunction as a key pathogenic mechanism. Some patients, however, display no motor response at maximal TMS intensities, termed here an 'inexcitable' motor cortex. The extent to which this cortical difference impacts clinical outcomes remains unclear. The aim of this study was to determine the clinical profile of patients with inexcitability to TMS., Methods: Motor cortex excitability was evaluated using TMS. Patients in whom a motor evoked potential could not be recorded in one or more limbs at maximal TMS intensities were classified as four-limb or partially inexcitable. Demographic information, clinical variables and survival data were analysed., Results: From 133 patients, 40 were identified with inexcitability. Patients with four-limb inexcitability were younger (P = 0.03) and had lower-limb disease onset (64%), greater functional disability (P < 0.001) and faster disease progression (P = 0.02), particularly if inexcitability developed within 1 year of symptoms (P < 0.01). Patients with partial inexcitability had higher resting motor thresholds compared to the excitable cohort (P < 0.01), but averaged short-interval intracortical inhibition was similar (P = 0.5). Mean survival was reduced if inexcitability involved all limbs within 12 months of symptom onset (P = 0.04)., Conclusion: Amyotrophic lateral sclerosis patients with inexcitability of all four limbs to TMS have a distinct clinical profile of younger age and lower-limb onset. Importantly, these patients display a more malignant disease trajectory, with faster progression, greater functional disability and reduced survival when occurring in early disease. This measure may provide an important prognostic marker in amyotrophic lateral sclerosis., (© 2020 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)
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- 2021
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19. [Monomelic amyotrophy. Report of one case].
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Matamala JM, Cea G, Salinas R, Vidal A, López I, Marileo R, and Stuardo A
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- Adult, Cervical Vertebrae diagnostic imaging, Electromyography, Hand diagnostic imaging, Humans, Magnetic Resonance Imaging, Male, Young Adult, Spinal Muscular Atrophies of Childhood complications, Spinal Muscular Atrophies of Childhood diagnosis
- Abstract
Monomelic amyotrophy, also known as Hirayama disease, is a rare lower motor neuron syndrome due to localized lower motor neuron loss in the spinal cord at the cervical level. Clinically, monomelic amyotrophy is defined by the insidious onset of unilateral atrophy and weakness involving the hand and forearm, typically beginning in the second or third decade of life. We report 19-year-old man with a two years history of slowly progressive unilateral weakness and atrophy of his right-hand muscles. Neurological examination revealed weakness and atrophy in his intrinsic hand muscles, with sparing of the abductor pollicis brevis muscle. Also, mild atrophy of the ulnar aspect of the forearm was detected with sparing of the brachioradialis muscle. Electromyography showed active and chronic neurogenic changes affecting C8 and T1 myotomes, with mild chronic neurogenic changes on C7 myotome. Magnetic resonance imaging of his cervical spine revealed spinal cord atrophy involving C5 to C7 segments, associated with forward displacement of the posterior wall of the dura in cervical spine flexion. The clinical features associated with the imaging and electrophysiological findings support the diagnosis of monomelic amyotrophy.
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- 2021
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20. Interrogating interneurone function using threshold tracking of the H reflex in healthy subjects and patients with motor neurone disease.
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Howells J, Sangari S, Matamala JM, Kiernan MC, Marchand-Pauvert V, and Burke D
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- Adult, Aged, Female, Humans, Male, Middle Aged, Motor Neuron Disease diagnosis, Motor Neurons physiology, Muscle, Skeletal physiopathology, Neural Inhibition, Peroneal Nerve physiopathology, Synaptic Potentials, Electromyography methods, H-Reflex, Interneurons physiology, Motor Neuron Disease physiopathology
- Abstract
Objective: The excitability of the lower motoneurone pool is traditionally tested using the H reflex and a constant-stimulus paradigm, which measures changes in the amplitude of the reflex response. This technique has limitations because reflex responses of different size must involve the recruitment or inhibition of different motoneurones. The threshold-tracking technique ensures that the changes in excitability occur for an identical population of motoneurones. We aimed to assess this technique and then apply it in patients with motor neurone disease (MND)., Methods: The threshold-tracking approach was assessed in 17 healthy subjects and 11 patients with MND. The soleus H reflex was conditioned by deep peroneal nerve stimulation producing reciprocal Ia and so-called D1 and D2 inhibitions, which are believed to reflect presynaptic inhibition of soleus Ia afferents., Results: Threshold tracking was quicker than the constant-stimulus technique and reliable, properties that may be advantageous for clinical studies. D1 inhibition was significantly reduced in patients with MND., Conclusions: Threshold tracking is useful and may be preferable under some conditions for studying the excitability of the motoneurone pool. The decreased D1 inhibition in the patients suggests that presynaptic inhibition may be reduced in MND., Significance: Reduced presynaptic inhibition could be evidence of an interneuronopathy in MND. It is possible that the hyperreflexia is a spinal pre-motoneuronal disorder, and not definitive evidence of corticospinal involvement in MND., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 International Federation of Clinical Neurophysiology. All rights reserved.)
- Published
- 2020
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21. A proposal for new diagnostic criteria for ALS.
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Shefner JM, Al-Chalabi A, Baker MR, Cui LY, de Carvalho M, Eisen A, Grosskreutz J, Hardiman O, Henderson R, Matamala JM, Mitsumoto H, Paulus W, Simon N, Swash M, Talbot K, Turner MR, Ugawa Y, van den Berg LH, Verdugo R, Vucic S, Kaji R, Burke D, and Kiernan MC
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- Electromyography standards, Humans, Motor Neurons physiology, Muscle, Skeletal physiopathology, Reference Standards, Amyotrophic Lateral Sclerosis diagnosis, Electromyography methods
- Abstract
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
- Published
- 2020
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22. Early focality and spread of cortical dysfunction in amyotrophic lateral sclerosis: A regional study across the motor cortices.
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Dharmadasa T, Matamala JM, Howells J, Vucic S, and Kiernan MC
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- Female, Functional Laterality physiology, Humans, Male, Middle Aged, Transcranial Magnetic Stimulation, Amyotrophic Lateral Sclerosis physiopathology, Evoked Potentials, Motor physiology, Motor Cortex physiopathology, Neural Conduction physiology
- Abstract
Objective: To characterise the regional cortical patterns underlying clinical symptomatology in amyotrophic lateral sclerosis (ALS)., Methods: 138 patients prospectively underwent transcranial magnetic stimulation studies from hand and leg cortical regions of each hemisphere, obtaining motor evoked potentials from all four limbs. Patients were categorised by clinical phenotype and underwent clinical and peripheral evaluation of disease., Results: Cortical dysfunction was evident across the motor cortices, with reduction in short-interval intracortical inhibition (SICI) suggesting the presence of widespread cortical hyperexcitability, most prominently from clinically affected regions (hand p < 0.0001; leg p < 0.01). In early disease, cortical abnormalities were asymmetric between hemispheres, focally corresponding to clinical site-of-onset (p < 0.05). Degrees of cortical dysfunction varied between phenotypes, with the bulbar-onset cohort demonstrating greatest reduction in SICI (p = 0.03)., Conclusions: The pattern of cortical dysfunction appears linked to clinical evolution in ALS, with early focal asymmetry preceding widespread changes in later disease. Cortical differences across phenotypes may influence clinical variability., Significance: This is the first study to extensively map cortical abnormalities from multiple motor regions across hemispheres. The early cortical signature mirrors symptom laterality, supporting a discrete region of disease onset. Phenotypes appear to exist within a pathophysiological continuum, but cortical heterogeneity may mediate observed differences in clinical outcome., Competing Interests: Declaration of Competing Interest None of the authors have potential conflicts of interest to be disclosed., (Crown Copyright © 2019. Published by Elsevier B.V. All rights reserved.)
- Published
- 2020
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23. Epidemiology of chronic inflammatory demyelinating polyneuropathy in the South-Eastern area of Santiago, Chile.
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Cea G, Idiáquez JF, Salinas R, Matamala JM, Villagra R, and Stuardo A
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- Adult, Aged, Chile epidemiology, Diabetes Mellitus epidemiology, Female, Humans, Incidence, Male, Middle Aged, Prevalence, Polyradiculoneuropathy, Chronic Inflammatory Demyelinating epidemiology
- Abstract
Chronic inflammatory demyelinating polyneuropathy (CIDP) is an immune-mediated polyneuropathy. It usually has an insidious onset, progressive course and heterogeneous clinical features. As far as we know, there is no epidemiological information on CIDP in South America and the Caribbean. Our aim was to estimate the frequency of CIDP in the South-Eastern region of Santiago, where our hospital is based and the population number assigned is officially reported every year by the health authorities. Records of 581 patients registered with the diagnosis of neuropathy were found and all patients meeting the diagnostic criteria of the EFNS/PNS for definitive and possible CIDP were included. Data were collected using a data extraction protocol designed by the authors and which included demographic, clinical, laboratory and electrophysiological information. The estimated prevalence and incidence of CIDP were 2.95/100,000 and 0.46/100,000 respectively. Fifteen patients (8 men, 7 women) were classified as definitive or possible CIDP. Nine patients had typical CIDP and three also had diabetes mellitus. The prevalence and incidence rates were similar to those reported in other regions of the world., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020. Published by Elsevier Ltd.)
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- 2020
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24. NOTCH3 Gene Mutation in a Chilean Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy Family.
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Gallardo A, Latapiat V, Rivera A, Fonseca B, Roldan A, Sandoval P, Sánchez C, and Matamala JM
- Subjects
- CADASIL diagnosis, CADASIL mortality, CADASIL therapy, Chile, Genetic Predisposition to Disease, Heredity, Humans, Male, Middle Aged, Pedigree, Phenotype, Prognosis, Risk Factors, CADASIL genetics, Mutation, Receptor, Notch3 genetics
- Abstract
Introduction: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a rare hereditary stroke disorder caused by mutations in the NOTCH3 gene. We report the first Chilean CADASIL family with complete radiological and histological studies., Methods: The family tree was constructed from an autopsy-confirmed confirmed patient, and includes 3 generations. We performed clinical, pathologic, genetic, and radiologic examinations on members of a family with CADASIL., Results: In the second generation, findings compatible with CADASIL were identified in 6 individuals, all of whom had a missense mutation in exon 3 (c.268C>T) resulting in an arginine to cysteine amino acid substitution at position 90 (R90C). In the third generation, a missense mutation was detected in one of the 4 asymptomatic individuals., Conclusions: There are similarities in clinical presentation between this family and previously described Asian and European series with R90C mutations. Detecting genotypes with a gain or loss of cysteine residues opens the door to future gene transfection-based therapies., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2020
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25. Clinical neurophysiology standards of EMG instrumentation: Twenty years of changes.
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Verdugo RJ and Matamala JM
- Subjects
- Electromyography, Neurophysiology
- Published
- 2020
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26. Single fiber EMG guidelines: Moving towards a "single" methodological consensus.
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Matamala JM and Verdugo RJ
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- Consensus, Electromyography
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- 2019
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27. Relationship between infarct size and serum uric acid levels during the acute phase of stroke.
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Fernández-Gajardo R, Matamala JM, Gutiérrez R, Lozano P, Cortés-Fuentes IA, Sotomayor CG, Bustamante G, Pasten JA, Vargas G, Guerrero R, Reyes P, Cavada G, Feuerhake W, and Rodrigo R
- Subjects
- Female, Fluorescence Recovery After Photobleaching, Humans, Linear Models, Magnetic Resonance Imaging, Male, Middle Aged, Stroke diagnostic imaging, Stroke physiopathology, Antioxidants metabolism, Stroke blood, Uric Acid blood
- Abstract
Introduction: Uric acid has gained considerable attention as a potential neuroprotective agent in stroke during the last decades, however, its role in the pathophysiology of ischemic stroke remains poorly understood. A serial evaluation of uric acid levels during the acute phase of stroke and its association with infarct size on magnetic resonance imaging is lacking., Methods: We present a cohort study of 31 patients with ischemic stroke who were not candidates for thrombolysis according to current criteria at the time. We performed daily measurements of serum uric acid and total antioxidant capacity of plasma during the first week after symptoms onset and 30 days after. Infarct size was determined in the acute phase by a DWI sequence and the final infarct size with a control MRI (FLAIR) at day 30., Results: Uric acid significantly decreases between days 2 to 6 compared to day 1, after adjustment by sex, age and DWI at diagnosis, with a nadir value at 72h. A mixed model analysis showed a negative association between DWI at diagnosis and uric acid evolution during the first week after stroke. Moreover, multivariable linear regression of uric acid values during follow up on DWI volumes demonstrated that DWI volume at diagnosis is negatively associated with uric acid levels at day 3 and 4. There were no significant associations between total antioxidant capacity of plasma and DWI at diagnosis, or FLAIR at any point., Discussion: Patients with larger infarcts exhibited a significant decrease in serum uric acid levels, accounting for a more prominent reactive oxygen species scavenging activity with subsequent consumption and decay of this antioxidant. The different kinetics of total antioxidant capacity of plasma and serum uric acid levels suggests a specific role of uric acid in the antioxidant response in ischemic stroke., Competing Interests: The authors have declared that no competing interests exist.
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- 2019
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28. The effect of coil type and limb dominance in the assessment of lower-limb motor cortex excitability using TMS.
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Dharmadasa T, Matamala JM, Howells J, Simon NG, Vucic S, and Kiernan MC
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- Adult, Aged, Evoked Potentials, Motor physiology, Female, Humans, Male, Middle Aged, Muscle, Skeletal physiology, Young Adult, Cortical Excitability physiology, Functional Laterality physiology, Lower Extremity physiology, Motor Cortex physiology, Transcranial Magnetic Stimulation instrumentation, Transcranial Magnetic Stimulation methods
- Abstract
Purpose: Clinical application of transcranial magnetic stimulation (TMS) has rapidly increased but the majority of studies have targeted upper limb muscles, with few exploring the lower-limb. Differences of coil choice have added to methodological difficulties of lower-limb studies and have challenged consistent interpretation of these parameters. The aims of this study were to determine the optimal coil choice for assessing lower-limb cortical excitability and assess laterality of normal cortical function., Methods: 69 recordings were undertaken from the tibialis anterior muscle from 48 healthy participants. Three coil types currently used in lower-limb studies (90 mm circular; 70 mm figure-of-8; and 110 mm double cone) were explored using single pulse TMS and paired-pulse threshold tracking TMS (TT-TMS) paradigms, with peripheral function also assessed. Cortical symmetry was ascertained with bilateral recordings (dominant versus non-dominant muscles)., Results: The double-cone coil showed greatest efficacy, with significantly lower resting motor thresholds (49.0 ± 2.3%, p<0.0005) and greater intracortical facilitation compared to the alternate coil choices. Using the double-cone coil, paired-pulse TT-TMS generated an averaged short interval intracortical inhibition of 11.3 ± 1.2%, with an averaged intracortical facilitation of -6.1 ± 1.9%. There were no differences between dominant and non-dominant hemispheres., Conclusions: The present study identified key differences in cortical parameters between the currently utilised coils for lower-limb TMS. Specifically, this indicates the importance of standardizing the lower-limb TMS protocol, particularly for accurate interpretation in disease pathology., (Copyright © 2019 Elsevier B.V. All rights reserved.)
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- 2019
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29. Network approach identifies Pacer as an autophagy protein involved in ALS pathogenesis.
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Beltran S, Nassif M, Vicencio E, Arcos J, Labrador L, Cortes BI, Cortez C, Bergmann CA, Espinoza S, Hernandez MF, Matamala JM, Bargsted L, Matus S, Rojas-Rivera D, Bertrand MJM, Medinas DB, Hetz C, Manque PA, and Woehlbier U
- Subjects
- Amyotrophic Lateral Sclerosis genetics, Animals, Disease Models, Animal, Humans, Mice, Transgenic, Spinal Cord metabolism, Spinal Cord pathology, Superoxide Dismutase genetics, Superoxide Dismutase metabolism, Amyotrophic Lateral Sclerosis metabolism, Amyotrophic Lateral Sclerosis pathology, Autophagy drug effects, DNA-Binding Proteins metabolism, Motor Neurons metabolism
- Abstract
Background: Amyotrophic lateral sclerosis (ALS) is a multifactorial fatal motoneuron disease without a cure. Ten percent of ALS cases can be pointed to a clear genetic cause, while the remaining 90% is classified as sporadic. Our study was aimed to uncover new connections within the ALS network through a bioinformatic approach, by which we identified C13orf18, recently named Pacer, as a new component of the autophagic machinery and potentially involved in ALS pathogenesis., Methods: Initially, we identified Pacer using a network-based bioinformatic analysis. Expression of Pacer was then investigated in vivo using spinal cord tissue from two ALS mouse models (SOD1
G93A and TDP43A315T ) and sporadic ALS patients. Mechanistic studies were performed in cell culture using the mouse motoneuron cell line NSC34. Loss of function of Pacer was achieved by knockdown using short-hairpin constructs. The effect of Pacer repression was investigated in the context of autophagy, SOD1 aggregation, and neuronal death., Results: Using an unbiased network-based approach, we integrated all available ALS data to identify new functional interactions involved in ALS pathogenesis. We found that Pacer associates to an ALS-specific subnetwork composed of components of the autophagy pathway, one of the main cellular processes affected in the disease. Interestingly, we found that Pacer levels are significantly reduced in spinal cord tissue from sporadic ALS patients and in tissues from two ALS mouse models. In vitro, Pacer deficiency lead to impaired autophagy and accumulation of ALS-associated protein aggregates, which correlated with the induction of cell death., Conclusions: This study, therefore, identifies Pacer as a new regulator of proteostasis associated with ALS pathology.- Published
- 2019
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30. [Idiopathic inflammatory myopathies. A review].
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Acosta I, Matamala JM, Jara P, Pino F, Gallardo A, and Verdugo R
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- Antibodies, Dermatomyositis pathology, Electromyography, Humans, Immunosuppressive Agents classification, Immunosuppressive Agents therapeutic use, Muscle, Skeletal pathology, Myositis drug therapy, Polymyositis pathology, Myositis pathology
- Abstract
Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of acquired immune-mediated diseases, which typically involve the striated muscle with a variable involvement of the skin and other organs. Clinically, they are characterized by proximal muscle weakness, elevation of muscle enzymes, myopathic changes on electromyography and an abnormal muscle biopsy. The different IIM have been classified according to their distinctive histopathologic features in dermatomyositis (DM), polymyositis (PM), inclusion body myositis (IBM) and immune-mediated necrotizing myopathy (IMNM). Several myositis-specific antibodies are associated with the different phenotypes, as well as with different risk of neoplastic disease and systemic complications. The basis for the treatment of DM, PM, and IMNM is immunosuppression. For IBM there are only symptomatic treatments. Steroids, associated or not with other immunosuppressant drugs, are the first line of treatment. Biologic drugs will allow future individualized therapies. The 10-year survival of DM, PM and IMNM is 62 to 90%. The leading causes of death are neoplastic, lung and cardiac complications. IBM does not impair survival, although it affects the quality of life.
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- 2019
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31. Amyotrophic lateral sclerosis diagnostic index: Toward a personalized diagnosis of ALS.
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Geevasinga N, Howells J, Menon P, van den Bos M, Shibuya K, Matamala JM, Park SB, Byth K, Kiernan MC, and Vucic S
- Subjects
- Adult, Aged, Amyotrophic Lateral Sclerosis physiopathology, Diagnosis, Differential, Female, Humans, Male, Middle Aged, Neural Inhibition, Neuromuscular Diseases diagnosis, Prospective Studies, Sensitivity and Specificity, Amyotrophic Lateral Sclerosis diagnosis, Evoked Potentials, Motor, Transcranial Magnetic Stimulation methods
- Abstract
Objective: The aim of the study was to assess the utility of a novel amyotrophic lateral sclerosis (ALS) diagnostic index (ALSDI)., Methods: A prospective multicenter study was undertaken on patients presenting with suspected ALS. The reference standard (Awaji criteria) was applied to all patients at recruitment. Patients were randomly assigned to a training (75%) and a test (25%) cohort. The ALSDI was developed in the training cohort and its diagnostic utility was subsequently assessed in the test cohort., Results: A total of 407 patients were recruited, with 305 patients subsequently diagnosed with ALS and 102 with a non-ALS mimicking disorder. The ALSDI reliably differentiated ALS from neuromuscular disorders in the training cohort (area under the curve 0.92, 95% confidence interval 0.89-0.95), with ALSDI ≥4 exhibiting 81.6% sensitivity, 89.6% specificity, and 83.5% diagnostic accuracy. The ALSDI diagnostic utility was confirmed in the test cohort (area under the curve 0.90, 95% confidence interval 0.84-0.97), with ALSDI ≥4 exhibiting 83.3% sensitivity, 84% specificity, and 83.5% diagnostic accuracy. In addition, the diagnostic utility of the ALSDI was confirmed in patients who were Awaji negative at recruitment and in those exhibiting a predominantly lower motor neuron phenotype., Conclusion: The ALSDI reliably differentiates ALS from mimicking disorders at an early stage in the disease process., Classification of Evidence: This study provides Class I evidence that for patients with suspected ALS, the ALSDI distinguished ALS from neuromuscular mimicking disorders., (© 2019 American Academy of Neurology.)
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- 2019
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32. Comparison of cross-sectional areas and distal-proximal nerve ratios in amyotrophic lateral sclerosis.
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Noto YI, Garg N, Li T, Timmins HC, Park SB, Shibuya K, Shahrizaila N, Huynh W, Matamala JM, Dharmadasa T, Yiannikas C, Vucic S, and Kiernan MC
- Subjects
- Adult, Aged, Electromyography, Female, Forearm innervation, Humans, Male, Middle Aged, Neural Conduction physiology, ROC Curve, Severity of Illness Index, Statistics, Nonparametric, Ultrasonography, Wrist innervation, Amyotrophic Lateral Sclerosis diagnostic imaging, Amyotrophic Lateral Sclerosis pathology, Median Nerve diagnostic imaging, Spinal Nerves diagnostic imaging
- Abstract
Introduction: This study explored potential diagnostic markers of nerve ultrasound in differentiating amyotrophic lateral sclerosis (ALS) from mimic disorders., Methods: Ultrasound of the median, ulnar, and tibial nerves was conducted in 53 patients with ALS, 32 patients with ALS-mimic disorders, and 30 controls. Nerve cross-sectional area (CSA) and distal-proximal ratios were calculated., Results: The median nerve CSA in the upper arm was decreased (7.9 ± 1.3 mm
2 vs. 9.0 ± 1.4 mm2 , P < 0.05), and the median nerve wrist-upper arm ratio was increased in ALS patients compared with controls (1.3 ± 0.4 vs. 1.1 ± 0.2; P < 0.01). In differentiating ALS from mimic presentations, assessment of median nerve CSA in the upper arm and comparison of a median and ulnar nerve CSA distal-proximal ratio provide diagnostic potential., Discussion: Assessment of nerve CSA combined with calculation of nerve CSA distal-proximal ratio provides a useful marker to aid in the diagnosis of ALS. Muscle Nerve 58:777-783, 2018., (© 2018 Wiley Periodicals, Inc.)- Published
- 2018
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33. In vivo evidence for reduced ion channel expression in motor axons of patients with amyotrophic lateral sclerosis.
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Howells J, Matamala JM, Park SB, Garg N, Vucic S, Bostock H, Burke D, and Kiernan MC
- Subjects
- Action Potentials, Adult, Aged, Electric Stimulation, Female, Humans, Ion Channels genetics, Male, Middle Aged, Amyotrophic Lateral Sclerosis metabolism, Gene Expression Regulation physiology, Ion Channels metabolism, Motor Neurons physiology
- Abstract
Key Points: The progressive loss of motor units in amyotrophic lateral sclerosis (ALS) is initially compensated for by the reinnervation of denervated muscle fibres by surviving motor axons. A disruption in protein homeostasis is thought to play a critical role in the pathogenesis of ALS. The changes in surviving motor neurons were studied by comparing the nerve excitability properties of moderately and severely affected single motor axons from patients with ALS with those from single motor axons in control subjects. A mathematical model indicated that approximately 99% of the differences between the ALS and control units could be explained by a non-selective reduction in the expression of all ion channels. These changes in ALS patients are best explained by a failure in the supply of ion channel and other membrane proteins from the diseased motor neuron., Abstract: Amyotrophic lateral sclerosis (ALS) is characterised by a progressive loss of motor units and the reinnervation of denervated muscle fibres by surviving motor axons. This reinnervation preserves muscle function until symptom onset, when some 60-80% of motor units have been lost. We have studied the changes in surviving motor neurons by comparing the nerve excitability properties of 31 single motor axons from patients with ALS with those from 21 single motor axons in control subjects. ALS motor axons were classified as coming from moderately or severely affected muscles according to the compound muscle action potential amplitude of the parent muscle. Compared with control units, thresholds were increased, and there was reduced inward and outward rectification and greater superexcitability following a conditioning impulse. These abnormalities were greater in axons from severely affected muscles, and were correlated with loss of fine motor skills. A mathematical model indicated that 99.1% of the differences between the moderately affected ALS and control units could be explained by a reduction in the expression of all ion channels. For the severely affected units, modelling required, in addition, an increase in the current leak through and under the myelin sheath. This might be expected if the anchoring proteins responsible for the paranodal seal were reduced. We conclude that changes in axonal excitability identified in ALS patients are best explained by a failure in the supply of ion channel and other membrane proteins from the diseased motor neuron, a conclusion consistent with recent animal and in vitro human data., (© 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.)
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- 2018
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34. A unified model of the excitability of mouse sensory and motor axons.
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Makker PGS, Matamala JM, Park SB, Lees JG, Kiernan MC, Burke D, Moalem-Taylor G, and Howells J
- Subjects
- Animals, Axons physiology, Female, Humans, Male, Mice, Mice, Inbred C57BL, Action Potentials physiology, Models, Animal, Motor Neurons physiology, Sensory Receptor Cells physiology
- Abstract
Non-invasive nerve excitability techniques have provided valuable insight into the understanding of neurological disorders. The widespread use of mice in translational research on peripheral nerve disorders and by pharmaceutical companies during drug development requires valid and reliable models that can be compared to humans. This study established a novel experimental protocol that enables comparative assessment of the excitability properties of motor and sensory axons at the same site in mouse caudal nerve, compared the mouse data to data for motor and sensory axons in human median nerve at the wrist, and constructed a mathematical model of the excitability of mouse axons. In a separate study, ischaemia was employed as an experimental manoeuvre to test the translational utility of this preparation. The patterns of mouse sensory and motor excitability were qualitatively similar to human studies under normal and ischaemic conditions. The most conspicuous differences between mouse and human studies were observed in the recovery cycle and the response to hyperpolarization. Modelling showed that an increase in temperature in mouse axons could account for most of the differences in the recovery cycle. The modelling also suggested a larger hyperpolarization-activated conductance in mouse axons. The kinetics of this conductance appeared to be much slower raising the possibility that an additional or different hyperpolarization-activated cyclic-nucleotide gated (HCN) channel isoform underlies the accommodation to hyperpolarization in mouse axons. Given a possible difference in HCN isoforms, caution should be exercised in extrapolating from studies of mouse motor and sensory axons to human nerve disorders., (© 2018 Peripheral Nerve Society.)
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- 2018
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35. [Neuropathy and Fabry's disease. Report of five cases].
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Jara P, Matamala JM, and Verdugo R
- Subjects
- Adult, Analgesics, Non-Narcotic therapeutic use, Carbamazepine therapeutic use, Enzyme Replacement Therapy, Fabry Disease drug therapy, Female, Humans, Male, Middle Aged, Peripheral Nervous System Diseases diagnosis, Sensitivity and Specificity, Somatosensory Disorders diagnosis, Young Adult, Fabry Disease diagnosis
- Abstract
Fabry's disease is an X-linked multisistemic lisosomal storage disorder caused by deficiency or absence in α-Galatosidase A. Symptoms develop early in childhood with small fiber neuropathy, autonomic disorders and skin lesions (angiokeratomas). More severe in males, patients develop over years heart disease (hypertrophic cardiomyopathy, bradycardia), proteinuria, renal failure, transient ischemic attacks and stroke, associated with decreased life expectancy. We report five patients with Fabry's disease aged between 21 to 56 years and with family history. Neuropathic symptoms are described and neurophysiological testing findings of nerve conduction studies, quantitative sensory testing, autonomic testing and sympathetic skin response are presented.
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- 2018
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36. Primary lateral sclerosis and the amyotrophic lateral sclerosis-frontotemporal dementia spectrum.
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Agarwal S, Highton-Williamson E, Caga J, Matamala JM, Dharmadasa T, Howells J, Zoing MC, Shibuya K, Geevasinga N, Vucic S, Hodges JR, Ahmed RM, and Kiernan MC
- Subjects
- Aged, Amyotrophic Lateral Sclerosis classification, Cognition, Disability Evaluation, Disease Progression, Female, Frontotemporal Dementia classification, Humans, Kaplan-Meier Estimate, Male, Middle Aged, Motor Cortex physiopathology, Motor Neuron Disease classification, Neuropsychological Tests, Survival Analysis, Transcranial Magnetic Stimulation, Amyotrophic Lateral Sclerosis physiopathology, Amyotrophic Lateral Sclerosis psychology, Frontotemporal Dementia physiopathology, Frontotemporal Dementia psychology, Motor Neuron Disease physiopathology, Motor Neuron Disease psychology
- Abstract
Aim: To investigate whether primary lateral sclerosis (PLS) represents part of the amyotrophic lateral sclerosis-frontotemporal dementia (ALS-FTD) spectrum of diseases., Methods: Comprehensive assessment was taken on 21 patients with PLS and results were compared to patients diagnosed with pure motor ALS (n = 27) and ALS-FTD (n = 12). Clinical features, Addenbrooke's Cognitive Examination (ACE) scores, Motor Neuron Disease Behaviour (Mind-B) scores, motor disability on the ALS functional rating scale (ALSFRS) and survival times were documented. Motor cortex excitability was evaluated using transcranial magnetic stimulation (TMS)., Results: Global cognition was impaired in PLS (mean total ACE score 82.5 ± 13.6), similar to ALS-FTD (mean total ACE score 76.3 ± 7.7, p > 0.05) while behavioural impairments were not prominent. TMS revealed that resting motor threshold (RMT) was significantly higher in PLS (75.5 ± 6.2) compared ALS-FTD (50.1 ± 7.2, p < 0.001) and ALS (62.3 ± 12.6, p = 0.046). Average short-interval intracortical inhibition (SICI) was similar in all three patient groups. The mean survival time was longest in PLS (217.4 ± 22.4 months) and shortest in ALS-FTD (38.5 ± 4.5 months, p = 0.002). Bulbar onset disease (β = - 0.45, p = 0.007) and RMT (β = 0.54, p = 0.001) were independent predictors of global cognition while motor scores (β = 0.47, p = 0.036) and SICI (β = 0.58, p = 0.006) were significantly associated with ALSFRS., Conclusion: The cognitive profile in PLS resembles ALS-FTD, without prominent behavioural disturbances. A higher RMT in PLS than ALS and ALS-FTD is consistent with differential cortical motor neuronal abnormalities and more severe involvement of corticospinal axons while SICI, indicative of inhibitory interneuronal dysfunction was comparable with ALS and ALS-FTD. Overall, while these findings support the notion that PLS lies on the ALS-FTD spectrum, the mechanisms underlying slow disease progression are likely to be distinct in PLS.
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- 2018
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37. Excitability of sensory axons in amyotrophic lateral sclerosis.
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Matamala JM, Howells J, Dharmadasa T, Huynh W, Park SB, Burke D, and Kiernan MC
- Subjects
- Adult, Aged, Amyotrophic Lateral Sclerosis diagnosis, Cross-Sectional Studies, Female, Humans, Male, Middle Aged, Prospective Studies, Action Potentials physiology, Amyotrophic Lateral Sclerosis physiopathology, Axons physiology, Sensory Receptor Cells physiology
- Abstract
Objective: To evaluate the excitability of sensory axons in patients with amyotrophic lateral sclerosis (ALS)., Methods: Comprehensive sensory nerve excitability studies were prospectively performed on 28 sporadic ALS patients, compared to age-matched controls. Sensory nerve action potentials were recorded from digit 2 following median nerve stimulation at the wrist. Disease severity was measured using motor unit number estimation (MUNE), the revised ALS Functional Rating Scale (ALSFRS-R) and the MRC scale., Results: There were no significant differences in standard and extended measures of nerve excitability between ALS patients and controls. These unchanged excitability measures included accommodation to long-lasting hyperpolarization and the threshold changes after two supramaximal stimuli during the recovery cycle. Excitability parameters did not correlate with MUNE, ALSFRS-R, APB MRC scale or disease duration., Conclusions: This cross-sectional study has identified normal axonal membrane properties in myelinated sensory axons of ALS patients. Previously described sensory abnormalities could be the result of axonal fallout, possibly due to a ganglionopathy, or to involvement of central sensory pathways rostral to gracile and cuneate nuclei., Significance: These results demonstrate the absence of generalized dysfunction of the membrane properties of sensory axons in ALS in the face of substantial deficits in motor function., (Copyright © 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)
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- 2018
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38. Inter-session reliability of short-interval intracortical inhibition measured by threshold tracking TMS.
- Author
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Matamala JM, Howells J, Dharmadasa T, Trinh T, Ma Y, Lera L, Vucic S, Burke D, and Kiernan MC
- Subjects
- Adult, Electromyography, Evoked Potentials, Motor, Female, Humans, Male, Middle Aged, Motor Cortex physiology, Reproducibility of Results, Young Adult, Cortical Excitability, Neural Inhibition, Transcranial Magnetic Stimulation methods
- Abstract
Paired-pulse transcranial magnetic stimulation (TMS) using fixed test stimuli suffers from marked variability of the motor evoked potential (MEP) amplitude. Threshold tracking TMS (TT-TMS) was introduced to overcome this problem. The aim of this work was to describe the absolute and relative reliability of short-interval intracortical inhibition (SICI) using TT-TMS. Cortical excitability studies were performed on twenty-six healthy subjects over three sessions (two recordings on the same day and one seven days apart), with MEPs recorded over abductor pollicis brevis. Reliability was established by calculating the standard error of the measurements (SEm), minimal detectable change (MDC) and intraclass correlation coefficient (ICC). Resting motor threshold and averaged SICI presented the lowest SEm and highest ICCs. SICI at 1 ms showed a higher SEm than SICI at 3 ms, suggesting different physiological processes, but averaging SICI over a number of intervals greatly increases the reproducibility. The variability was lower for tests undertaken at the same time of day seven days apart compared to tests performed on the same day, and in both instances the ICC for averaged SICI was ≥0.81. The MDC in averaged SICI was reduced from 6.7% to 2% if the number of subjects was increased from one to eleven. In conclusion, averaged SICI is the most reproducible variable across paired-pulse TT-TMS measures, showing an excellent ICC. It is recommended that, in longitudinal studies, testing be performed at the same time of day and that changes in cortical excitability should be measured and averaged over a number of interstimulus intervals to minimise variability., (Copyright © 2018 Elsevier B.V. All rights reserved.)
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- 2018
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39. Ectopic impulse generation in peripheral nerve hyperexcitability syndromes and amyotrophic lateral sclerosis.
- Author
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Noto YI, Simon NG, Selby A, Garg N, Shibuya K, Shahrizaila N, Huynh W, Matamala JM, Dharmadasa T, Park SB, Vucic S, and Kiernan MC
- Subjects
- Adult, Aged, Amyotrophic Lateral Sclerosis diagnostic imaging, Electromyography, Fasciculation diagnostic imaging, Female, Humans, Male, Middle Aged, Muscle, Skeletal diagnostic imaging, Peripheral Nervous System Diseases diagnostic imaging, Transcranial Magnetic Stimulation, Ultrasonography, Amyotrophic Lateral Sclerosis physiopathology, Cortical Excitability physiology, Fasciculation physiopathology, Motor Neurons physiology, Muscle, Skeletal physiopathology, Peripheral Nervous System Diseases physiopathology
- Abstract
Objective: To elucidate differences in the distribution and firing frequency of fasciculations between peripheral nerve hyperexcitability syndromes and amyotrophic lateral sclerosis (ALS) and to explore the generator site of fasciculations., Methods: Ultrasound of 14 preselected muscles was performed in patients with peripheral hyperexcitability and ALS. The distribution and firing frequency of fasciculations were calculated. Cortical excitability assessment was also done by threshold tracking transcranial magnetic stimulation., Results: In total, 518 muscles from 37 peripheral hyperexcitability patients and 756 muscles from 54 ALS patients were examined. Regarding the detection rate, 74% of muscles in ALS patients demonstrated fasciculations, compared with 34% of muscles in peripheral hyperexcitability patients (P < 0.001). The number of unique repeating focal muscle fasciculation movements per muscle and firing frequency of individual fasciculations in ALS were both significantly higher than those in peripheral hyperexcitability (P < 0.001). Furthermore, cortical silent period duration negatively correlated with the number and firing frequency of fasciculations in ALS (P < 0.05). A similar relationship was not evident in peripheral hyperexcitability., Conclusions: In ALS patients, fasciculations were more widespread, greater in number and higher in firing frequency than in peripheral hyperexcitability patients., Significance: A significant proportion of fasciculations in ALS may be influenced by changes in central excitability., (Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.)
- Published
- 2018
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40. Genome-wide circulating microRNA expression profiling reveals potential biomarkers for amyotrophic lateral sclerosis.
- Author
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Matamala JM, Arias-Carrasco R, Sanchez C, Uhrig M, Bargsted L, Matus S, Maracaja-Coutinho V, Abarzua S, van Zundert B, Verdugo R, Manque P, and Hetz C
- Subjects
- Adult, Aged, Animals, Biomarkers blood, Disease Models, Animal, Female, Humans, Male, Mice, Transgenic, Amyotrophic Lateral Sclerosis diagnosis, Amyotrophic Lateral Sclerosis genetics, Circulating MicroRNA blood, Circulating MicroRNA genetics, Genome-Wide Association Study, Transcriptome genetics
- Abstract
The occurrence of mutations of TDP-43, FUS, and C9ORF72 in amyotrophic lateral sclerosis (ALS) suggests pathogenic alterations to RNA metabolism and specifically to microRNA (miRNA) biology. Moreover, several ALS-related proteins impact stress granule dynamics affecting miRNA biogenesis and cellular miRNA levels. miRNAs are present in different biological fluids and have been proposed as potential biomarkers. Here we used next-generation sequencing to perform a comparative analysis of the expression profile of circulating miRNAs in the serum of 2 mutant superoxide dismutase 1 transgenic mice. Top hit candidates were then validated using quantitative real-time polymerase chain reaction, confirming significant changes for 6 miRNAs. In addition, one of these miRNAs was also altered in mutant TDP-43 mice. Then, we tested this set of miRNAs in the serum from sporadic ALS patients, observing a significant deregulation of hsa-miR-142-3p and hsa-miR-1249-3p. A negative correlation between the revised ALS functional rating scale and hsa-miR-142-3p levels was found. Bioinformatics analysis of the regulatory network governed by hsa-miR-142-3p identified TDP-43 and C9orf72 as possible targets, suggesting a connection with ALS pathogenesis. This study identifies miRNAs that are altered in ALS that may serve as potentials biomarkers., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2018
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41. Cerebral ring enhancing lesion with diffusion restriction in a South American patient.
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Matamala JM, Fernández-Gajardo R, Yañez A, Cea G, and Salinas R
- Subjects
- Diagnosis, Differential, Diffusion Magnetic Resonance Imaging, Humans, Brain, Magnetic Resonance Imaging
- Published
- 2018
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42. O 6 -methylguanine-DNA-methyltransferase immunostaining intensity in glioblastoma.
- Author
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Jiménez D, Matamala JM, Chiti A, Vergara C, Tissera C, Melo R, and Cartier L
- Subjects
- DNA, Humans, Brain Neoplasms, DNA Modification Methylases metabolism, DNA Repair Enzymes metabolism, Glioblastoma, Tumor Suppressor Proteins metabolism
- Abstract
Immunohistochemistry (IHC) for O
6 -methylguanine-DNA-methyltransferase (MGMT) has shown heterogeneous results. Cell staining intensity has not been included as a quantifiable variable in IHC analyses. We performed MGMT IHC in 29 patients diagnosed as glioblastoma classifying cells into three categories based on nuclear staining intensity compared with adjacent endothelium. The median proportions of strong-moderate, weak and no staining cells were 10%, 16% and 71%, respectively. The proportion of positive cases for MGMT expression varies from 38% to 52% depending on the classification of weakly stained cells. This letter challenges previous studies that have not included intensity as a variable for IHC analysis., (Copyright © 2017 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.)- Published
- 2018
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43. [O6-methylguanine-DNA-methyltransferase (MGMT) expression in patients with glioblastoma multiforme].
- Author
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Jiménez D, Matamala JM, Chiti A, Vergara C, Tissera C, Melo R, and Cartier L
- Subjects
- Adult, Aged, Biomarkers, Tumor genetics, Brain Neoplasms genetics, Chile, Female, Gene Expression Regulation, Neoplastic, Glioblastoma genetics, Humans, Immunohistochemistry, Male, Middle Aged, O(6)-Methylguanine-DNA Methyltransferase genetics, Prognosis, Retrospective Studies, Survival Rate, Biomarkers, Tumor metabolism, Brain Neoplasms enzymology, Glioblastoma enzymology, O(6)-Methylguanine-DNA Methyltransferase metabolism
- Abstract
Background: Patients with Glioblastoma multiforme (GBM) have a five years survival of less than 5%, but the response to chemotherapy with alkylating agents can vary depending on the methylation status of O6-methylguanine-DNA-methyltransferase (MGMT). Genetic testing has limitations for routine use, while immunohistochemistry (IHC) offers a fast and affordable technique but with heterogeneous results in the literature., Aim: To evaluate MGMT expression by IHC in tumor tissue of Chilean patients with GBM., Material and Methods: Tumor samples of 29 patients with a pathological diagnosis of GBM were studied. We performed IHC staining and manual analysis of positive and negative cells for MGMT expression. A cut-off of at least 10% of cells expressing MGMT was used. Demographic and clinical features of patients were obtained from clinical records., Results: The median number of cells counted per case was 692 (interquartile range [IQR] 492-928). Fifteen cases (52%) were positive for MGMT expression. Median overall survival was 5.3 months (IQR 3.4-12-8). The effect of MGMT expression on the therapeutic response was not studied since only 3 patients received chemotherapy., Conclusions: Our results are similar to international reports, but we were not able to determine the association between MGMT expression and therapeutic response.
- Published
- 2018
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44. Motor neurone disease.
- Author
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Dharmadasa T, Matamala JM, Huynh W, Zoing MC, and Kiernan MC
- Subjects
- Humans, Motor Neuron Disease physiopathology
- Abstract
Motor neurone disease (MND) patients exhibit poor gait, balance, and postural control, all of which significantly increases their risk of falling. Falls are frequent in the MND population, and are associated with an increased burden of disease. The complex interplay of both motor and extramotor manifestations in this disease contributes to the heterogeneous and multifactorial causes of such dysfunction. This review highlights the pathophysiologic influence of motor degeneration in gait disturbance, but also the additional influence on postural instability from other inputs such as cognitive impairment, autonomic dysregulation, cerebellar dysfunction, sensory impairment, and extrapyramidal involvement. In various combinations, these impairments are responsible for reduced gait speed and alteration in gait cycle, as well as structurally more variable and disorganized gait patterns. Based on these features, this chapter will also provide disease-specific interventions to assess, manage, and prevent falls in the MND cohort., (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Published
- 2018
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45. Detection of fasciculations in amyotrophic lateral sclerosis: The optimal ultrasound scan time.
- Author
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Noto YI, Shibuya K, Shahrizaila N, Huynh W, Matamala JM, Dharmadasa T, and Kiernan MC
- Subjects
- Aged, Cohort Studies, Female, Humans, Male, Middle Aged, Muscle, Skeletal diagnostic imaging, Muscle, Skeletal physiopathology, Prospective Studies, Time Factors, Ultrasonography standards, Video Recording methods, Amyotrophic Lateral Sclerosis diagnostic imaging, Amyotrophic Lateral Sclerosis physiopathology, Fasciculation diagnostic imaging, Fasciculation physiopathology, Video Recording standards
- Abstract
Introduction: This study seeks to elucidate the optimal scan time to detect fasciculations by using ultrasound in the diagnosis of amyotrophic lateral sclerosis (ALS)., Methods: The intervals between fasciculations were recorded from tongue, abdominal, and limb muscles in ALS patients, incorporating assessment of the cumulative probability of 2 fasciculations occurring., Results: From prospective studies of 228 muscles from 19 ALS patients, fasciculations were detectable in 68% of patients. The longest interfasciculation interval recorded was 81.4 s in the hand muscle. The cumulative probability of 2 fasciculations occurring was calculated as ≥0.9 in all muscles during a period of 60 s., Discussion: A definition of 2 or more fasciculations occurring during a scan time of 60 s reliably allowed detection of fasciculations in ALS. Muscle Nerve, 2017., (© 2017 Wiley Periodicals, Inc.)
- Published
- 2017
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46. [Acute polyradiculoneuropathy associated with human Herpes Virus 7 in an immunocompetent patient. Case report].
- Author
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Jara P, Matamala JM, Verdugo R, and Thompson L
- Subjects
- Acute Disease, Adult, Humans, Magnetic Resonance Imaging, Male, Polymerase Chain Reaction, Herpesvirus 7, Human isolation & purification, Immunocompetence, Polyradiculoneuropathy virology, Roseolovirus Infections complications
- Abstract
Human herpes virus 7 (HHV-7) is a cause of encephalitis, meningitis and myeloradiculoneuropathy in adults who are immunocompetent or with immunosuppression. The involvement of the peripheral nervous system is always associated with myelitis. We report a case of acute polyradiculoneuropathy due to HHV-7, without involvement of central nervous system, in an immunocompetent patient. A 35-years-old man complained of lumbar pain radiating to both buttocks. On examination muscle strength and tendon reflexes were normal. He had asymmetric pinprick and light touch saddle hypoesthesia and also in the perineal region, dorsum and lateral aspect of the left foot. Magnetic resonance imaging showed mild thickening and contrast enhancement of cauda equina nerve roots. Polymerase chain reaction performed on cerebrospinal fluid was positive for HVV-7. Other inflammatory, infectious and neoplastic etiologies were ruled out. Lumbar pain and hypoesthesia improved progressively and neurological examination was normal after one month. He did not receive antiviral therapy.
- Published
- 2017
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47. Cortical function and corticomotoneuronal adaptation in monomelic amyotrophy.
- Author
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Matamala JM, Geevasinga N, Huynh W, Dharmadasa T, Howells J, Simon NG, Menon P, Vucic S, and Kiernan MC
- Subjects
- Adult, Cohort Studies, Female, Humans, Male, Middle Aged, Prospective Studies, Spinal Muscular Atrophies of Childhood diagnosis, Young Adult, Adaptation, Physiological physiology, Evoked Potentials, Motor physiology, Motor Cortex physiopathology, Motor Neurons physiology, Spinal Muscular Atrophies of Childhood physiopathology, Transcranial Magnetic Stimulation methods
- Abstract
Objective: To evaluate corticomotoneuronal integrity in monomelic amyotrophy using threshold tracking transcranial magnetic stimulation (TT-TMS)., Methods: Cortical excitability studies were prospectively performed in 8 monomelic amyotrophy patients and compared to 21 early-onset amyotrophic lateral sclerosis (ALS) patients and 40 healthy controls. Motor evoked potentials responses were recorded over abductor pollicis brevis., Results: Maximal motor evoked potential (MEP/CMAP ratio) was significantly increased in monomelic amyotrophy compared with controls (monomelic amyotrophy 51.2±12.4%; control 22.7±2.1%, p=0.04). Averaged short-interval intracortical inhibition (SICI, ISI 1-7ms) in monomelic amyotrophy patients was similar to controls (monomelic amyotrophy 9.6±2.1%; control 10.0±0.9%, p=0.98). However, it was significantly reduced in early-onset ALS in comparison with monomelic amyotrophy patients (monomelic amyotrophy 9.6±2.1%; ALS 2.3±1.7%, p<0.001). Averaged SICI is a good parameter (area under the curve 0.79, p=0.02) to discriminate between monomelic amyotrophy and early-onset ALS patients., Conclusions: TT-TMS technique has identified normal cortical function in monomelic amyotrophy, a feature that distinguishes it from early-onset ALS. The greater corticomotoneuronal projections to spinal motoneurons may represent central nervous system adaptive change in monomelic amyotrophy., Significance: Corticomotoneuronal dysfunction does not drive the lower motor neurone loss presented in monomelic amyotrophy., (Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)
- Published
- 2017
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48. Dynamic muscle ultrasound identifies upper motor neuron involvement in amyotrophic lateral sclerosis.
- Author
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Noto YI, Simon N, Shibuya K, Matamala JM, Dharmadasa T, and Kiernan MC
- Subjects
- Adult, Aged, Amyotrophic Lateral Sclerosis physiopathology, Cohort Studies, Deglutition physiology, Electromyography methods, Female, Humans, Male, Middle Aged, Neck Muscles physiopathology, Prospective Studies, Ultrasonography methods, Amyotrophic Lateral Sclerosis diagnostic imaging, Motor Neurons pathology, Neck Muscles diagnostic imaging
- Abstract
Objective: The aim of the present study was to elucidate the pattern of change in bulbar muscles using ultrasound in patients diagnosed with amyotrophic lateral sclerosis (ALS)., Methods: Changes in the mylohyoid and geniohyoid muscle complex (mylohyoid-geniohyoid-muscle-complex) thickness were recorded while swallowing 5 ml of water using M-mode ultrasound in 30 ALS patients compared to 20 healthy controls. The ratio of mylohyoid-geniohyoid-muscle-complex thickness as determined by the maximum thickness of mylohyoid-geniohyoid-muscle-complex during swallowing divided by thickness at rest, was compared between ALS patients and controls, with the correlation between thickness ratio, echogenicity and clinical parameters assessed., Results: Overall, the thickness ratio in ALS patients was 1.39 ± 0.23 (mean ± SD) compared to 1.55 ± 0.17 in controls (p < 0.05). In sub-analysis, the thickness ratio was significantly decreased in ALS patients with bulbar-onset disease compared to those with limb-onset disease (p < 0.01) and controls (p < 0.01). Thickness ratio negatively correlated with the severity of upper motor neuron involvement in the bulbar region (p < 0.05)., Conclusions: Bulbar muscle ultrasound represents a novel method to detect impaired mobility and thereby provides an objective assessment of upper motor neuron involvement in the bulbar region of ALS patients.
- Published
- 2017
- Full Text
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49. Differentiating lower motor neuron syndromes.
- Author
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Garg N, Park SB, Vucic S, Yiannikas C, Spies J, Howells J, Huynh W, Matamala JM, Krishnan AV, Pollard JD, Cornblath DR, Reilly MM, and Kiernan MC
- Subjects
- Anterior Horn Cells pathology, Autoantibodies analysis, DNA Mutational Analysis, Diagnosis, Differential, Humans, Motor Neuron Disease genetics, Motor Neuron Disease pathology, Motor Neurons pathology, Muscular Atrophy, Spinal diagnosis, Muscular Atrophy, Spinal genetics, Muscular Atrophy, Spinal pathology, Polyradiculoneuropathy, Chronic Inflammatory Demyelinating diagnosis, Polyradiculoneuropathy, Chronic Inflammatory Demyelinating genetics, Polyradiculoneuropathy, Chronic Inflammatory Demyelinating pathology, Syndrome, Motor Neuron Disease diagnosis
- Abstract
Lower motor neuron (LMN) syndromes typically present with muscle wasting and weakness and may arise from pathology affecting the distal motor nerve up to the level of the anterior horn cell. A variety of hereditary causes are recognised, including spinal muscular atrophy, distal hereditary motor neuropathy and LMN variants of familial motor neuron disease. Recent genetic advances have resulted in the identification of a variety of disease-causing mutations. Immune-mediated disorders, including multifocal motor neuropathy and variants of chronic inflammatory demyelinating polyneuropathy, account for a proportion of LMN presentations and are important to recognise, as effective treatments are available. The present review will outline the spectrum of LMN syndromes that may develop in adulthood and provide a framework for the clinician assessing a patient presenting with predominantly LMN features., Competing Interests: Competing interests: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)
- Published
- 2017
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50. Prognostic factors in C9orf72 amyotrophic lateral sclerosis.
- Author
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Matamala JM, Dharmadasa T, and Kiernan MC
- Published
- 2017
- Full Text
- View/download PDF
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