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Introduction/Aims: Somatosensory evoked potentials (SSEPs) are described as a supportive tool to diagnose chronic inflammatory demyelinating polyradiculoneuropathy (CIDP); however, there is a lack of studies determining the effectiveness of SSEPs in monitoring the clinical course of individuals with this condition. The aims of this study are to evaluate the utility of SSEPs in monitoring patients with CIDP and to assess their association with clinical outcomes following immunomodulatory therapy. Methods: This was a single‐center retrospective observational study that included patients who met European Federation of Neurological Societies and Peripheral Nerve Society criteria for CIDP between 2018 and 2023. SSEPs were performed at diagnosis and during follow‐up after the start of immunomodulatory treatment. Fisher's exact test was employed to assess the association between clinical improvement and SSEP improvement. Results: Eighteen patients were included in the study. Ten patients had a typical CIDP pattern and 11 were male. In 17, SSEPs were abnormal prior to the start of immunomodulatory treatment. In patients who showed clinical improvement with immunomodulatory therapy, we observed that 15/17 had partial or complete improvement in SSEPs. Patients who showed no clinical improvement with first‐line treatment exhibited worsening SSEPs. There was a significant association between clinical and SSEPs improvement (p = 0.009). Discussion: We observed a positive association between improvement in SSEPs and clinical improvement in patients with CIDP. Our data suggest that SSEPs may be useful for monitoring the clinical course of patients with CIDP, but additional, larger studies are needed. [ABSTRACT FROM AUTHOR]

Introduction/objective: Biallelic expansion of the pentanucleotide AAGGG in the RFC1- gene is associated with cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS). This study aimed to comprehensively characterise this condition by conducting an in-depth neurophysiological examination of afflicted patients., Methods: A retrospective analysis was conducted in 31 RFC1-positive patients. Assessment included clinical examination and electrodiagnostic tests: nerve conduction studies, F waves, needle electromyography, H, blink and masseter reflexes; Autonomic Nervous System (ANS): Heart Rate Variability, Sympathetic Skin Response and Electrochemical Skin Conductance, and Quantitative Sensory Test (QST). Medullar tracts were assessed using Somatosensory Evoked Potentials (SEPs) and Transcranial Magnetic Stimulation., Results: All patients exhibited moderate to severe sensory axonal neuropathy/neuronopathy, whereas motor nerve conduction parameters and the pyramidal pathway showed no abnormalities. Tibial nerve SEPs were absent or severely attenuated in all patients, and were moderately affected by the median nerve. H-reflexes were preserved in 85.7% and blink reflex in 60% of tested patients. ANS tests yielded predominantly normal results, although 74% demonstrated impaired QST., Conclusions: Our findings highlight the characteristic features of sensory neuropathy/neuronopathy and severe somatosensory deficits, with predominantly preserved H-reflexes and motor sparing. Thermoalgesic fibres are frequently involved, whereas the ANS is relatively preserved., Significance: Neurophysiological examinations can objectively characterize the spectrum of RFC1-related disease., 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 © 2024 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Introduction: Pathogenic expansions in RFC1 have been described as a cause of a spectrum of disorders including late-onset ataxia, chronic cough, and cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS). Sensory neuronopathy/neuropathy appears to be a major symptom of RFC1-disorder, and RFC1 expansions are common in patients with sensory chronic idiopathic axonal neuropathy or sensory ganglionopathy. We aimed to investigate RFC1 expansions in patients with suspected RFC1-related disease followed-up in a Neuromuscular Diseases Unit, with a particular interest in the involvement of the peripheral nervous system., Methods: We recruited twenty consecutive patients based on the presence of at least two of the following features: progressive ataxia, sensory neuropathy/neuronopathy, vestibulopathy and chronic cough. Medical records were retrospectively reviewed for a detailed clinical description. More extensive phenotyping of the RFC1-positive patients and clinical comparison between RFC1 positive and negative patients were performed., Results: Biallelic AAGGG repeat expansions were identified in 13 patients (65%). The most frequent symptoms were chronic cough and sensory disturbances in the lower extremities (12/13). Only 4 patients (31%) had complete CANVAS. The phenotypes were sensory ataxia and sensory symptoms in extremities in 4/13; sensory ataxia, sensory symptoms, and vestibulopathy in 3/13; sensory symptoms plus chronic cough in 2/13. Chronic cough and isolated sensory neuronopathy were significantly more prevalent in RFC1-positive patients., Conclusion: Pathogenic RFC1 expansions are a common cause of sensory neuropathy/neuronopathy and should be considered in the approach to these patients. Identification of key symptoms or detailed interpretation of nerve conduction studies may improve patient selection for genetic testing., Competing Interests: Declaration of Competing Interest None of the authors has any conflict of interest to disclose in relation to this work., (Copyright © 2023. Published by Elsevier B.V.)

Introduction: The massive vaccination against the SARS-CoV-2 virus has demonstrated to be one of the major measures for the reduction of the morbidity and mortality that this virus causes. However, during the last months the administration of the vaccine has been also associated with some rare, but life-threatening, adverse effects., Case Report: In this article we describe the case of a patient that developed a Guillain-Barre syndrome and an Idiopathic thrombocytopenic purpura nine days after the vaccination with the third dose for the SARS-CoV-2 virus (Moderna). He had received previously two doses of the AstraZeneca vaccine. Moreover, the patient was positive for auto-antibodies anti-SSA/Ro60 and auto-antibodies IgG anti-GM1 and IgG anti-GM3., Discussion: Even though it is not possible to stablish a clear relation of causality between the administration of the vaccine booster for SARS-CoV-2 and the diseases developed by the patient, the association of two concomitant autoimmune processes is remarkable. As well as the positivity for the auto-antibodies anti-SSA/Ro60, which have been described in the bibliography in cases of SARS-CoV-2 infection.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that can rarely affect young individuals. Juvenile ALS (JALS) is defined for individuals with an onset of the disease before the age of 25. The contribution of genetics to ALS pathology is a field of growing interest. One of the differences between adult-onset ALS and JALS is their genetic background, with a higher contribution of genetic causes in JALS. We report a patient with JALS and a pathogenic variant in the TARDBP gene (c.1035C > G; p.Asn345Lys), previously reported only in adult-onset ALS, and with an atypical phenotype of marked upper motor neuron predominance. In addition, the proband presented an additional variant in the NEK1 gene, c.2961C > G (p.Phe987Leu), which is classified as a variant of unknown significance. Segregation studies showed a paternal origin of the TARDBP variant, while the variant in NEK1 was inherited from the mother. We hypothesize that the NEK1 variant acts as a disease modifier and suggests the possibility of a functional interaction between both genes in our case. This hypothesis could explain the peculiarities of the phenotype, penetrance, and the age of onset. This report highlights the heterogeneity of the phenotypic presentation of ALS associated with diverse pathogenic genetic variants., Competing Interests: The authors declare no conflict of interest.

Introduction: Weakness is a frequent complication in those critically ill due to COVID-19. This study describes its characteristics and the factors that can condition and predict it., Patients and Methods: We conducted a prospective, descriptive, observational study of patients admitted to the intensive care unit (ICU) due to COVID-19 between April and May 2020 with muscle weakness. A motor balance equal to or lower than 3/5 according to the modified Medical Research Council muscle strength scale was considered to be severe clinical impairment. Altogether 25 analytical studies, 16 neurophysiological studies and one muscle biopsy were performed, with a telephone follow-up at one month, a comparative analysis between the groups with and without severe compromise, and determination of cut-off points for analytical parameters to predict severe involvement using ROC curves., Results: The sample consisted of 25 patients with a mean age of 58 years (standard deviation ± 9). The median length of stay in the ICU was 27.5 days. All the electromyograms exhibited a myogenic pattern and 75% also showed neuropathy. The group with severe clinical involvement had higher levels of D-dimer (p = 0.08), lactate dehydrogenase (p = 0.03) and interleukin-6 (p = 0.10), and the combination of the alteration of any two of these three parameters predicted severe involvement with a sensitivity of 100% and a specificity of 76.9%. At one month of follow-up, 36% were unable to walk autonomously and 92% continued with muscle weakness., Conclusions: Weakness in severe COVID-19 patients has a major clinical impact. Its early detection and study by means of predictors of its development may allow for better management. The absence in some cases of classical risk factors for ICU-acquired weakness suggests a different pathophysiology.

Introduction: Levodopa-carbidopa intestinal gel (LCIG) infusion has demonstrated to improve motor fluctuations. The aim of this study is to assess the long-term safety and effectiveness of LCIG infusion in advanced Parkinson's disease (PD) patients with motor fluctuations and its effect in nonmotor symptoms., Methods: Adverse events (AE) and their management, clinical motor, and nonmotor aspects were assessed up to 10 years. Thirty-seven patients were treated with LGIC; in three subsets of patients, specific batteries of tests were used to assess cognitive and behavior assessment for 6 months, quality of sleep for 6 months, and quality of life and caregiver burden for 1 year., Results: There was a high number of AE, but manageable, most of mild and moderate severity. All patients experienced significant improvement in motor fluctuations with a reduction in mean daily off time of 4.87 hr after 3 months ( n  = 37) to 6.25 hr after 9 years ( n  = 2). Diskynesias remained stables in 28 patients (75.7%) and improved in 5 patients (13.5%). There was no neuropsychological deterioration, but an improvement in attentional functions, voluntary motor control, and semantic fluency. Quality of sleep did not worsen, and there was an improvement in the subjective parameters, although overnight polysomnography did not change. There was a significant sustained improvement of 37% in PD-Q39 after 3 months and to 1 year, and a significant reduction in caregiver burden of 10% after 3 months., Conclusion: LCIG infusion is a safe and efficacious treatment for the control of motor fluctuations, and for improvement or nonworsening of nonmotor aspects, long-term sustained, and feasible for use in routine care.

Background: Neurological complications after lung transplantation are common. The full spectrum of neurological complications and their impact on clinical outcomes has not been extensively studied., Methods: We investigated the neurological incidence of complications, categorized according to whether they affected the central, peripheral or autonomic nervous systems, in a series of 109 patients undergoing lung transplantation at our center between January 1 2013 and December 31 2014., Results: Fifty-one patients (46.8%) presented at least one neurological complication. Critical illness polyneuropathy-myopathy (31 cases) and phrenic nerve injury (26 cases) were the two most prevalent complications. These two neuromuscular complications lengthened hospital stays by a median period of 35.5 and 32.5 days respectively. However, neurological complications did not affect patients' survival., Conclusions: The real incidence of neurological complications among lung transplant recipients is probably underestimated. They usually appear in the first two months after surgery. Despite not affecting mortality, they do affect the mean length of hospital stay, and especially the time spent in the Intensive Care Unit. We found no risk factor for neurological complications except for long operating times, ischemic time and need for transfusion. It is necessary to develop programs for the prevention and early recognition of these complications, and the prevention of their precipitant and risk factors.

Objective: To assess the utility of bedside ultrasound combining B- and M-mode in the diagnosis of abnormal diaphragmatic motion in children after heart surgery., Design: Prospective post hoc blinded comparison of ultrasound performed by two different intensivists and fluoroscopy results with electromyography., Setting: Tertiary university hospital., Subjects: Children with suspected abnormal diaphragmatic motion after heart surgery., Interventions: None., Measurements and Main Results: Abnormal diaphragmatic motion was suspected in 26 children. Electromyography confirmed the diagnosis in 20 of 24 children (83.3%). The overall occurrence rate of abnormal diaphragmatic motion during the study period was 7.5%. Median patient age was 5 months (range, 16 d to 14 yr). Sensitivity and specificity of chest ultrasound performed at the bedside by the two intensivists (91% and 92% and 92% and 95%, respectively) were higher than those obtained by fluoroscopy (87% and 83%). Interobserver agreement (k) between both intensivists was 0.957 (95% CI, 0.87-100)., Conclusions: Chest ultrasound performed by intensivists is a valid tool for the diagnosis of diaphragmatic paralysis, presenting greater sensitivity and specificity than fluoroscopy. Chest ultrasound should be routinely used after pediatric heart surgery given its reliability, reproducibility, availability, and safety.

Biallelic mutations in the SBF1 gene have been identified in one family with demyelinating Charcot-Marie-Tooth disease (CMT4B3) and two families with axonal neuropathy and additional neurological and skeletal features. Here we describe novel sequence variants in SBF1 (c.1168C>G and c.2209_2210del) as the potential causative mutations in two siblings with severe axonal neuropathy, hearing loss, facial weakness and bulbar features. Pathogenicity of these variants is supported by co-segregation and in silico analyses and evolutionary conservation. Our findings suggest that SBF1 mutations may cause a syndromic form of autosomal recessive axonal neuropathy (AR-CMT2) in addition to CMT4B3.

Background: Myasthenia gravis (MG) is an autoimmune disease caused by a failure of neuromuscular transmission. Familial clustering has been reported despiteMG usually manifesting as a sporadic condition presumed not to be inherited. Our study investigated the prevalence of FAMG in a Spanish cohort, characterizing their phenotype,antibody titres and thymus findings., Material/methods: We investigated the presence of familial cases in 462 MG patients, characterizing by age and MGFA class at debut, quantitative MG score, antibody titres, MGFA post-intervention status and thymus pathology., Results: Sixteen cases from8 unrelated pedigrees were identified. The prevalence of FAMG caseswas 3.46%.Mean age at onset was 57.8 ± 17.4 years (range=23–82). Distribution at debut was: 6 ocular, 4 IIa, 4IIb, 1 IIIa and 1 IIIb. Thymoma was identified in two of the 7 thymectomized individuals., Conclusions: The prevalence of FAMG in Spain is similar to other populations. Post-intervention status did not differ from sporadic autoimmune MG. As in other neuromuscular disorders, phenotype and inheritance heterogeneity are present in FAMG. In addition to the interfamilial heterogeneity observed, members of the same family affected with FAMG may even present different ages of onset, severity and thymus involvement. Further studies are necessary to clarify the role of genetic risk factors in this form of autoimmune MG.

Background & Aims: Ornithine phenylacetate (OP) is a new drug that has been proposed for the treatment of hepatic encephalopathy (HE) because it decreases plasma ammonia. We performed a study to assess if OP would impact on neuronal function., Methods: Motor-evoked potentials (MEP), a surrogate of hepatic encephalopathy, were assessed (without anesthesia) in rats with portacaval anastomosis (PCA) that received gastrointestinal blood (GIB). Rats were pre-treated with OP prior to GIB. Ammonia and related metabolites (plasma, urine, and brain microdialysis) were assessed by HPLC and mass spectroscopy., Results: OP (one dose or 3 days) prevented disturbances in MEP induced by GIB in PCA rats. In rats treated with OP for 3 days, the amplitude and latency of MEP remained stable (-1% and +1%), while in the control group the amplitude decreased -21% and the latency increased +12% (p<0.01). OP attenuated the rise of ammonia in plasma by 45%, ammonia in brain microdialysate by 48%, induced a faster glutamine rise and the appearance of phenylacetylglutamine in plasma and urine. In addition, OP was associated with a lower concentration of ammonia and glutamate in brain microdialysate (approx. 50%)., Conclusions: OP prevents abnormalities in MEP precipitated by GIB in a model of HE. This is probably due to the enhancement of glutamine synthesis and metabolism, which results in a lower rise of plasma ammonia and the prevention of changes in glutamate in microdialysate. Thus, OP may be a good drug to prevent HE precipitated by gastrointestinal bleeding., (Copyright © 2011 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Unlabelled: Experimental models of hepatic encephalopathy (HE) are limited by difficulties in objectively monitoring neuronal function. There are few models that examine a well-defined neuronal pathway and lack the confounding effects of anesthetics. Motor-evoked potentials (MEPs) assess the function of the motor tract, which has been shown to be impaired in patients with cirrhosis. MEPs were elicited by cranial stimulation (central) and compound motor action potential by sciatic nerve stimulation (peripheral) in several models of HE in the rat. The experiments were performed using subcutaneous electrodes without anesthetics. Brain water content was assessed by gravimetry, brain metabolites were measured by magnetic resonance spectroscopy, and amino acids in microdialysates from the frontal cortex were analyzed by high-performance liquid chromatography. Abnormalities of MEP were observed in acute liver failure (ALF) induced by hepatic devascularization in relation to the progression of neurological manifestations. Similar disturbances were seen in rats with portocaval anastomosis after the administration of blood or lipopolysaccharide, but were absent in rats with biliary duct ligation. Hypothermia (≤35°C) and mannitol prevented the development of brain edema in acute liver failure, but only hypothermia avoided the decrease in the amplitude of MEP. Disturbances of MEP caused by the administration of blood into the gastrointestinal tract in rats with portocaval anastomosis were associated with an increase in ammonia, glutamine, and glutamate in brain microdialysate., Conclusion: Assessment of MEP in awake rats is a valid method to monitor HE in models of ALF and precipitated HE. This method shows the lack of efficacy of mannitol, a therapy that decreases brain edema, and relates disturbances of the function of the motor tract to ammonia and its metabolites., (Copyright © 2010 American Association for the Study of Liver Diseases.)