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Background Objectives Methods Results Conclusion There are few published data on the prevalence, pattern of anatomic distribution and predictors of various cranial tremors (eg, head, voice, jaw) in essential tremor (ET). Given the high levels of diagnostic misclassification in ET, data on observed clinical patterns would be valuable.To assess the prevalence, pattern of anatomic distribution and predictors of occurrence of cranial tremors in ET.ET cases who enrolled in two studies (respective n's = 301 and 175, total n = 476) underwent a detailed clinical assessment, which included a videotaped neurological examination. A senior movement disorders neurologist reviewed the examination and coded a range of cranial tremors as present or absent.The proportion of cases with any cranial tremor was 57.1% (Study 1) and 73.7% (Study 2). The following patterns emerged: (1) Head only and head + voice were the most commonly observed anatomical distribution of tremor. (2) Jaw tremors were rare, and face and tongue tremors, exceedingly rare. (3) There was a general layering‐on of tremor from head to head + voice to head + voice + jaw in more advanced cases. (4) Women were more likely to have head tremors than men, although there was no sex predilection tremor in other locations. (5) The likelihood of cranial tremor increased with greater tremor severity and age but was unrelated to tremor duration.We observed and quantified several patterns in the expression of cranial tremors in ET. Data on such patterns may assist clinicians and researchers in assigning diagnoses. [ABSTRACT FROM AUTHOR]

Objective: Tremor is a frequent co-occurring feature in patients with dystonia, especially in focal and segmental dystonia. Clinical studies have shown that tremor is more commonly observed when dystonia spreads to contiguous body regions. However, there is insufficient characterization of tremor physiology in focal and segmental forms of dystonia. We aimed to ascertain the characteristics of tremor presenting in these specific subtypes. Methods: We enrolled dystonia patients with head and arm tremors presenting to our center. We categorized these participants as focal and segmental dystonia following the Movement Disorders Society guidelines. We recorded the frequency, amplitude, rhythmicity, burst duration, and discharge pattern on accelerometer and electromyography recordings. We compared the physiology of tremors in focal vs. segmental dystonia. We determined whether the physiology was affected by clinical features such as demographics, age at onset, dystonia duration, alcohol responsiveness, family history, and botulinum toxin responsiveness. Results: 72 patients, mainly focal cervical dystonia and focal cervical + arm or cranial dystonia (segmental) were enrolled. In the analysis of the head tremor recordings (n = 66; frequency range 3-6.5 Hz), we found that focal vs. segmental dystonia comparisons revealed a significantly lower frequency (mean ± standard deviation; 4.0 ± 0.9 Hz vs. 4.7 ± 1.0 Hz; p = 0.02), lower amplitude (0.004 ± 0.008 g2/Hz vs. 0.006 ± 0.008 g2/Hz; p = 0.03) and longer muscle burst durations (111.1 ± 40.4 ms vs. 91.5 ± 24 ms; p = 0.04). In the analysis of arm tremor recordings (n = 31; frequency range 3.5-7 Hz), we found focal vs. segmental dystonia comparison revealed a lower amplitude (0.04 ± 0.07 g2/Hz vs. 0.06 ± 0.06 g2/Hz; p = 0.045). In the stepwise regression analysis, the age at evaluation (ß - 0.44; p = 0.006) and age at onset (ß - 0.61; p = 0.005) significantly predicted the head tremor frequency whereas the alcohol responsiveness tended to predict the amplitude of the head tremor (ß - 0.5; p = 0.04) and the arm tremor (ß - 0.6; p = 0.02). Conclusion: Our study found that the physiological characteristics of tremor in focal and segmental dystonia are somewhat distinct, suggesting that the spread of dystonia symptoms from one body region to another may have a bearing on the physiology of co-occurring tremor. The frequency of head tremors in younger participants was observed to be higher compared to older participants. The head and arm tremor tended be less severe in patients reporting alcohol responsiveness. [ABSTRACT FROM AUTHOR]

ObjectiveTremor is a frequent co-occurring feature in patients with dystonia, especially in focal and segmental dystonia. Clinical studies have shown that tremor is more commonly observed when dystonia spreads to contiguous body regions. However, there is insufficient characterization of tremor physiology in focal and segmental forms of dystonia. We aimed to ascertain the characteristics of tremor presenting in these specific subtypes.MethodsWe enrolled dystonia patients with head and arm tremors presenting to our center. We categorized these participants as focal and segmental dystonia following the Movement Disorders Society guidelines. We recorded the frequency, amplitude, rhythmicity, burst duration, and discharge pattern on accelerometer and electromyography recordings. We compared the physiology of tremors in focal vs. segmental dystonia. We determined whether the physiology was affected by clinical features such as demographics, age at onset, dystonia duration, alcohol responsiveness, family history, and botulinum toxin responsiveness.Results72 patients, mainly focal cervical dystonia and focal cervical + arm or cranial dystonia (segmental) were enrolled. In the analysis of the head tremor recordings (n = 66; frequency range 3–6.5 Hz), we found that focal vs. segmental dystonia comparisons revealed a significantly lower frequency (mean ± standard deviation; 4.0 ± 0.9 Hz vs. 4.7 ± 1.0 Hz; p = 0.02), lower amplitude (0.004 ± 0.008 g2/Hz vs. 0.006 ± 0.008 g2/Hz; p = 0.03) and longer muscle burst durations (111.1 ± 40.4 ms vs. 91.5 ± 24 ms; p = 0.04). In the analysis of arm tremor recordings (n = 31; frequency range 3.5–7 Hz), we found focal vs. segmental dystonia comparison revealed a lower amplitude (0.04 ± 0.07 g2/Hz vs. 0.06 ± 0.06 g2/Hz; p = 0.045). In the stepwise regression analysis, the age at evaluation (β - 0.44; p = 0.006) and age at onset (β - 0.61; p = 0.005) significantly predicted the head tremor frequency whereas the alcohol responsiveness tended to predict the amplitude of the head tremor (β - 0.5; p = 0.04) and the arm tremor (β - 0.6; p = 0.02).ConclusionOur study found that the physiological characteristics of tremor in focal and segmental dystonia are somewhat distinct, suggesting that the spread of dystonia symptoms from one body region to another may have a bearing on the physiology of co-occurring tremor. The frequency of head tremors in younger participants was observed to be higher compared to older participants. The head and arm tremor tended be less severe in patients reporting alcohol responsiveness.

Isolated head tremor (IHT) is a pathological condition characterized by tremor of the head without dystonic posturing or tremor in other parts of the body. In the past, head tremor was commonly referred to as essential tremor because it is very common in families of patients with essential tremor and may precede hand tremor. Several recent observations cast doubt on this theory. The irregular character of the tremor, the low efficacy of the drugs used for essential tremor and the use of botulinum neuroprotein type A with good response point to the dystonic character of the tremor. Neurophysiological evidence for a relationship between IHT and dystonia includes an altered somatosensory temporal discrimination threshold, metabolic changes according to DAT spectrography (positron emission spectrography to determine changes in dopamine levels) and a change in the blink reflex.

Background: Head tremor is common in dystonia syndromes and difficult to treat. Deep brain stimulation (DBS) is a therapeutic option in medically‐refractory cases. In most DBS‐centers, the globus pallidus internus (GPi) is targeted in patients with predominant dystonia and the ventrointermediate nucleus of the thalamus (Vim) in predominant tremor. The aim of the study was to evaluate the effect of GPi‐ versus Vim‐DBS in dystonic or essential head tremor. Methods: All patients with dystonia or essential tremor (ET) (n = 381) who underwent DBS surgery at our institution between 1999 and 2020 were screened for head tremor in our database according to predefined selection criteria. Of the 33 patients meeting inclusion criteria tremor and dystonia severity were assessed at baseline, short‐ (mean 10 months) and long‐term follow‐up (41 months) by two blinded video‐raters. Results: Twenty‐two patients with dystonic head tremor received either GPi‐ (n = 12) or Vim‐stimulation (n = 10), according to the prevailing clinical phenotype. These two groups were compared with 11 patients with ET, treated with Vim‐stimulation. The reduction in head tremor from baseline to short‐ and long‐term follow‐up was 60–70% and did not differ significantly between the three groups. Conclusions: GPi‐DBS effectively and sustainably reduced head tremor in idiopathic dystonia. The effect was comparable to the effect of Vim‐DBS on head tremor in dystonia patients with predominant limb tremor and to the effect of Vim‐DBS on head tremor in ET. [ABSTRACT FROM AUTHOR]

BackgroundHead tremor (HT) is a common feature of cervical dystonia (CD), usually quantified by subjective observation. Technological developments offer alternatives for measuring HT severity that are objective and amenable to automation.ObjectivesOur objectives were to develop CMOR (Computational Motor Objective Rater; a computer vision-based software system) to quantify oscillatory and directional aspects of HT from video recordings during a clinical examination and to test its convergent validity with clinical rating scales.MethodsFor 93 participants with isolated CD and HT enrolled by the Dystonia Coalition, we analyzed video recordings from an examination segment in which participants were instructed to let their head drift to its most comfortable dystonic position. We evaluated peak power, frequency, and directional dominance, and used Spearman's correlation to measure the agreement between CMOR and clinical ratings.ResultsPower averaged 0.90 (SD 1.80) deg2/Hz, and peak frequency 1.95 (SD 0.94) Hz. The dominant HT axis was pitch (antero/retrocollis) for 50%, roll (laterocollis) for 6%, and yaw (torticollis) for 44% of participants. One-sided t-tests showed substantial contributions from the secondary (t = 18.17, p

IntroductionA common view is that head tremor (HT) in cervical dystonia (CD) decreases when the head assumes an unopposed dystonic posture and increases when the head is held at midline. However, this has not been examined with objective measures in a large, multicenter cohort.MethodsFor 80 participants with CD and HT, we analyzed videos from examination segments in which participants were instructed to 1) let their head drift to its most comfortable position (null point) and then 2) hold their head straight at midline. We used our previously developed Computational Motor Objective Rater (CMOR) to quantify changes in severity, amplitude, and frequency between the two postures.ResultsAlthough up to 9% of participants had exacerbated HT in midline, across the whole cohort, paired t-tests reveal no significant changes in overall severity (t = -0.23, p = 0.81), amplitude (t = -0.80, p = 0.43), and frequency (t = 1.48, p = 0.14) between the two postures.ConclusionsWhen instructed to first let their head drift to its null point and then to hold their head straight at midline, most patient's changes in HT were below the thresholds one would expect from the sensitivity of clinical rating scales. Counter to common clinical impression, CMOR objectively showed that HT does not consistently increase at midline posture in comparison to the null posture.

Essential tremor (ET) may present with head tremor (HT), of presumed cerebellar nature. Deep brain stimulation (DBS) targeting the ventral intermediate (Vim) nucleus of the thalamus is a highly effective therapy for medication-refractory ET. However, stimulation-related side effects may include cerebellar abnormalities, such as postural instability. This retrospective cohort study evaluated the risk of post-Vim DBS postural instability (primary outcome measure) in patients with versus without head tremor (HT vs. nHT). The primary outcome measure, namely post-DBS postural instability, was assessed in both groups using a Wilcoxon rank sum t-test. The time to postural instability was determined using Cox proportional hazards regression analysis adjusted for age and sex. Out of 30 patients analyzed during the follow up period, there was similar postural instability detected in HT (9/14, 64%) and nHT patients (11/16, 69%) at 24 months post-Vim DBS (p=0.82), adjusted hazard ratio[aHR]=0.82, p=0.69). These data suggest that the presence or absence of HT does not have an impact on postural instability after bilateral Vim DBS in patients with ET. [ABSTRACT FROM AUTHOR]

Simple Summary: Canine idiopathic head tremor syndrome (CIHTS) represents a condition characterized by an episodic, uncontrolled horizontal ("no"), vertical ("yes") or rotatory movement of the head in dogs. The condition appears to affect young adults, starting when a dog is less active or at rest and stops after applying a stimulus. CIHTS can be an expression of a partial epilepsy. To date, there is a limited number of CIHTS cases in which an electroencephalographic pattern was identified. In this paper, we describe a dog with clinical signs of CIHTS in which a new pattern of interictal epileptic discharges was identified. Canine idiopathic head tremor syndrome (CIHTS) represents a benign condition characterized by episodic, uncontrolled movement of the head. Even though the condition might be an expression of a partial motor epilepsy, to date, there is a limited number of studies describing the electroencephalographic features. In this report, we describe the case of a dog diagnosed with partial motor epilepsy resembling CIHTS symptomatology, a new slow spike–wave complex pattern similar to that of Lennox–Gastaut syndrome in humans identified on electroencephalographic examination. We also studied the efficacy of phenobarbitone therapy over a period of two years. [ABSTRACT FROM AUTHOR]

BackgroundAlthough abnormal head and neck postures are defining features of cervical dystonia (CD), head tremor (HT) is also common. However, little is known about the relationship between abnormal postures and HT in CD.MethodsWe analyzed clinical data and video recordings from 185 patients enrolled by the Dystonia Coalition. We calculated the likelihood of their HT and HT type ("regular" vs. "jerky") given directionality of abnormal head postures, disease duration, sex, and age.ResultsPatients with retrocollis were more likely to have HT than patients with anterocollis (X2 (1, N = 121) = 7.98, p = 0.005). There was no difference in HT likelihood given left or right turning in laterocollis and rotation. Patients with HT had longer disease duration (t(183) = 2.27, p = 0.024). There was no difference in age between patients with and without HT. In a logistic regression model, anterocollis/retrocollis direction (X2 (1, N = 121) = 6.04, p = 0.014), disease duration (X2 (1, N = 121) = 7.28, p = 0.007), and the interaction term between age and disease duration (X2 (1, N = 121) = 7.77, p = 0.005) collectively contributed to HT likelihood. None of the postural directionality or demographic variables were associated with differential likelihood of having regular versus jerky HT.DiscussionWe found that HT is more likely for CD patients with a specific directionality in their predominant posture. Our finding that CD patients with longer disease duration have a higher likelihood of HT also raises the question of whether HT becomes more likely over time in individual patients.

Background: Midline essential tremor (Mid-ET) is a distinctive group of essential tremor (ET) in which tremor affects the neck, jaw, tongue, and/or voice. For long, it has been considered as an ultimate stage of the disease and a marker of its severity. However, recent studies pointed its complexity in terms of non-motor presentation. Thus, we aimed to investigate the non-motor signs (NMS) in Mid-ET.Design: We conducted a cross-sectional study in a tertiary neurology referral center including ET patients classified into two groups based on the presence or not of midline tremor (Mid-ET vs. No-Mid-ET). We assessed NMS using the non-motor severity scale (NMSS), a large battery of cognitive tests, clinical and electrophysiological study of the autonomic nervous system along with the evaluation of sleep disturbances.Results: A total of 163 patients were included: Mid-ET (n = 79) and No-Mid-ET (n = 84) matched in gender and age of onset. Mid-ET patients had higher proportion of late-onset ET (> 60 years old, p = 0.002) and more extrapyramidal signs (p = 0.005). For NMS, Mid-ET was marked with cognitive dysfunction (p = 0.008). The hallmarks of the neuropsychiatric profile of Mid-ET were executive dysfunction (p = 0.004), attention problems (p < 0.000), episodic memory impairment (p = 0.003), and greater depression (p = 0.010). The presence of RBD was a trait of Mid-ET (p = 0.039). In both Mid-ET and No-Mid-ET phenotypes, clinical and neurophysiological dysautonomia correlated with cognitive dysfunction.Conclusion: Mid-ET patients had greater cognitive dysfunction, depression, RBD, higher proportion of late-onset ET, and more extrapyramidal signs. Taken all together, these findings could provide a redesigned insight into the underlying physiopathology of Mid-ET indicative of a greater cerebellar dysfunction. [ABSTRACT FROM AUTHOR]

Canine idiopathic head tremor syndrome (CIHTS) represents a benign condition characterized by episodic, uncontrolled movement of the head. Even though the condition might be an expression of a partial motor epilepsy, to date, there is a limited number of studies describing the electroencephalographic features. In this report, we describe the case of a dog diagnosed with partial motor epilepsy resembling CIHTS symptomatology, a new slow spike–wave complex pattern similar to that of Lennox–Gastaut syndrome in humans identified on electroencephalographic examination. We also studied the efficacy of phenobarbitone therapy over a period of two years.

Background: Although abnormal head and neck postures are defining features of cervical dystonia (CD), head tremor (HT) is also common. However, little is known about the relationship between abnormal postures and HT in CD. Methods: We analyzed clinical data and video recordings from 185 patients enrolled by the Dystonia Coalition. We calculated the likelihood of their HT and HT type (“regular” vs. “jerky”) given directionality of abnormal head postures, disease duration, sex, and age. Results: Patients with retrocollis were more likely to have HT than patients with anterocollis (X2 (1, N = 121) = 7.98, p = 0.005). There was no difference in HT likelihood given left or right turning in laterocollis and rotation. Patients with HT had longer disease duration (t(183) = 2.27, p = 0.024). There was no difference in age between patients with and without HT. In a logistic regression model, anterocollis/retrocollis direction (X2 (1, N = 121) = 6.04, p = 0.014), disease duration (X2 (1, N = 121) = 7.28, p = 0.007), and the interaction term between age and disease duration (X2 (1, N = 121) = 7.77, p = 0.005) collectively contributed to HT likelihood. None of the postural directionality or demographic variables were associated with differential likelihood of having regular versus jerky HT. Discussion: We found that HT is more likely for CD patients with a specific directionality in their predominant posture. Our finding that CD patients with longer disease duration have a higher likelihood of HT also raises the question of whether HT becomes more likely over time in individual patients.

Dystonia is the third most common movement disorder affecting three million people worldwide. Cervical dystonia is the most common form of dystonia. Despite common prevalence the pathophysiology of cervical dystonia is unclear. Traditional view is that basal ganglia is involved in pathophysiology of cervical dystonia, while contemporary theories suggested the role of cerebellum and proprioception in the pathophysiology of cervical dystonia. It was recently proposed that the cervical dystonia is due to malfunctioning of the head neural integrator – the neuron network that normally converts head velocity to position. Most importantly the neural integrator model was inclusive of traditional proposal emphasizing the role of basal ganglia while also accommodating the contemporary view suggesting the involvement of cerebellum and proprioception. It was hypothesized that the head neural integrator malfunction is the result of impairment in cerebellar, basal ganglia, or proprioceptive feedback that converge onto the integrator. The concept of converging input from the basal ganglia, cerebellum, and proprioception to the network participating in head neural integrator explains that abnormality originating anywhere in the network can lead to the identical motor deficits – drifts followed by rapid corrective movements – a signature of neural integrator dysfunction. We tested this hypothesis in an experiment examining simultaneously recorded globus pallidal single-unit activity, synchronized neural activity (local field potential), and electromyography (EMG) measured from the neck muscles during the standard-of-care deep brain stimulation surgery in 12 cervical dystonia patients (24 hemispheres). Physiological data were collected spontaneously or during voluntary shoulder shrug activating the contralateral trapezius muscle. The activity of pallidal neurons during shoulder shrug exponentially decayed with time constants that were comparable to one measured from the pretectal neural integrator and the trapezius electromyography. These results show that evidence of abnormal neural integration is also seen in globus pallidum, and that latter is connected with the neural integrator. Pretectal single neuron responses consistently preceded the muscle activity; while the globus pallidum internus response always lagged behind the muscle activity. Globus pallidum externa had equal proportion of lag and lead neurons. These results suggest globus pallidum receive feedback from the muscles or the efference copy from the integrator or the other source of the feedback. There was bi-hemispheric asymmetry in the pallidal single-unit activity and local field potentials. The asymmetry correlated with degree of lateral head turning in cervical dystonia patients. These results suggest that bihemispheric asymmetry in the feedback leads to asymmetric dysfunction in the neural integrator causing head turning.

Background: Directional, deep-brain stimulation may prove beneficial for targets (1) thinner along the lead trajectory, and (2) whose borders are not easily visible by neuroimaging. When targeting the ventral intermediate (VIM) nucleus of the thalamus for essential tremor, even baseline ataxia may be exacerbated by medial spread of current and antidromic stimulation of vestibular-cerebellar-thalamic afferents. Case Report: The present patient with essential tremor developed refractory head tremor leading to implantation of bilateral St. Jude/Abbott segmented leads into the VIM to afford additional programming options. Discussion: Video evidence showed that directional stimulation did not exacerbate ataxia beyond baseline, whereas nondirectional stimulation exacerbated ataxia consistently. We discuss how this programming advantage may help address a common complication from DBS implantation for essential tremor patients.

Background: Although head tremor (HT) and pain are prevalent in cervical dystonia (CD), their joint relationship to phenotypic features of focal dystonia remains unclear. Objectives: We examined how severity of HT and pain are associated with age of CD onset and duration, and whether HT subtypes ("jerky" or "regular") exhibit distinct relationships between severity of HT and pain. Methods: The severity of HT and pain were assessed with the Toronto Western Spasmodic Torticollis Rating Scale in retrospective review of 188 CD patients recruited through the Dystonia Coalition. Results: HT severity was associated with longer CD duration (p < 0.0005), whereas pain severity was associated with younger age at onset (p = 0.043). HT severity and pain severity were not correlated for jerky HT (p = 0.996), but positively correlated for regular HT (p = 0.01). Conclusions: The distinct associations of HT and pain with age at onset, disease duration, and HT subtype further characterize the heterogeneity of CD's clinical presentation and suggest similarly heterogeneous underlying mechanisms. [ABSTRACT FROM AUTHOR]

Introduction: Resting limb tremor (RLT) is a well known feature in parkinsonism. There is very little information on resting head tremor (RHT) in parkinsonism, and none in pathologically confirmed cases. The association between RLT and RHT remains uncertain.Methods: A Caucasian male developed upper limb tremor and voice changes at age 70. He was first assessed at our clinic at age 72. At age 73 he developed resting head tremor (RHT) which prevented him from falling asleep. His status was documented in longitudinal follow-up at our clinic. He had a total of 14 clinical evaluations and four videos made over 6 years. Autopsy of the brain and spinal cord was performed.Results: The resting head tremor improved on antiparkinsonian drugs and resolved completely after four years. Coincident with RHT remission, the upper limb tremor worsened and interfered with feeding, and his lower limb resting tremor became more pronounced. During his course he developed slow, scanning speech and all the cardinal motor findings of parkinsonism. There was no ophthalmoplegia. Post-mortem neuropathological examination revealed prominent progressive supranuclear palsy (PSP) changes and minor Lewy body pathology.Conclusion: This is the first autopsy confirmed case of parkinsonism with RHT. He had dual pathology. Dissociation between RHT and RLT indicates that the oscillatory brain centers for the two were different in this case. [ABSTRACT FROM AUTHOR]

Head tremor in patients with dystonia is referred to as dystonic tremor. During surgical treatment, numerous targets may be selected, including the internal segment of the globus pallidus and the ventral intermediate (Vim) nucleus; however, there is no consensus concerning the most effective treatment target. We report herein a case of dystonic head tremor in which improvement persisted for 5 years after deep brain stimulation (DBS) of the bilateral thalamic Vim and ventro-oral internus (Voi) nuclei. The patient, a 67-year-old woman, has a horizontal head tremor associated with cervical dystonia that had been resistant to drug treatment over 3 years. Immediately following surgery, dystonia and tremor symptoms had completely improved. Voice volume declined and dysarthria occurred but improved upon adjusting the stimulation conditions. Over 5 years, both head tremor and cervical dystonia have been completely controlled, and no other obvious complications have been observed. As the Voi nucleus receives pallidothalamic projections involved in dystonia and the Vim nucleus receives cerebellothalamic projections involved in tremors, stimulating these 2 nuclei with the same electrode appears reasonable in the treatment of dystonic tremor. This case suggests that Vim-Voi DBS may be effective for treating dystonic head tremor. [ABSTRACT FROM AUTHOR]

Traditional Chinese veterinary medicine (TCVM) including acupuncture, Chinese herbal medicine, food therapy and Tui-na is focused on providing a unique group of strategies for therapy of neurological disorders. Recent studies have looked at improved treatment of neurological disease by optimizing strategies using traditional Chinese veterinary medicine versus the sole use of conventional treatments. In this case series, successful management of brain and spinal cord disease with acupuncture as the sole treatment or acupuncture and Chinese herbal medicine combined is documented in 3 dogs. [ABSTRACT FROM AUTHOR]

Background: A defining characteristic of dystonia is its position-dependence. In cervical dystonia (CD), sensory tricks ameliorate head tremor (HT). But it remains unknown whether raising the arms alone has the same impact. Methods: We analyzed data collected from patients enrolled by the Dystonia Coalition. For 120 patients with HT, we assessed how raising their arms without touching their head changed their HT severity. Results: Forty-eight out of 120 patients exhibited changes in HT severity when raising their arms. These patients were more likely to exhibit decreases in HT severity (N = 35) than increases (N = 13, X2 (1, N = 48) = 10.1, p = 0.002). Demographic factors and sensory trick efficacy were not significant predictors of whether HT severity changed when raising their arms. Discussion: Raising the arms without touching the head is a posture that can reduce HT severity in some CD patients. Our results extend the concept of position-dependent motor symptoms in CD to include the position of the arms. [ABSTRACT FROM AUTHOR]

BackgroundDeep brain stimulation (DBS) of the posterior subthalamic area (PSA) provides a potentially effective treatment for medication-refractory essential tremor (ET).ObjectiveTo study the clinical benefits and adverse-event profile of bilateral PSA-DBS for refractory ET.MethodsSeven patients with refractory ET underwent bilateral PSA-DBS surgery under general anesthesia between September 2017 and May 2018. Clinical outcome assessments, using the Essential Tremor Rating Scale, were performed at 1-, 6-, and 12-month follow-up, except for the last assessment of one patient who was followed up to 9 months. Analysis was focused on changes in patients’ motor symptoms and quality of life following surgery as well as documenting the adverse-event profile associated with the surgical PSA-DBS treatment.ResultsAfter surgery, patients’ motor symptoms, including upper limb tremor and head tremor, were improved by 84.2% and their quality of life by 81.25% at 1-month follow-up. The clinical benefits to patients were maintained at 6-month and last follow-up. Adverse side effects included dysarthria (n = 4), balance disorder (n = 2), and paresthesia of the right limb (n = 1). No habituation effects were observed throughout the follow-up.ConclusionBilateral PSA-DBS seems to offer an effective and safe alternative treatment for medically intractable ET, warranting further research into its clinical utility, adverse-event profile, and comparative effectiveness.

Objectives: Essential tremor (ET) patients presenting tremor in the midline structures may be a distinct subtype of the syndrome. Therefore, we sought to explore the clinical manifestations, especially non‐motor symptoms (NMS) of Chinese ET patients with midline tremor (MT). Methods: In the cross‐sectional study, we grouped 290 definite or probable ET patients based on their MT conditions. The NMS in ET patients were evaluated using the NMS scale (NMSS). NMS and other clinical correlates were then compared among subgroups with, and without MT. Results: We revealed that 39.0%, 27.6%, and 6.9% of the patients respectively had neck, voice, and facial tremors. With the accumulation of tremor in midline structures, NMS became more severe and prevalent. Logistic regression analyses revealed that factors such as: female gender (OR = 2.164, 95% CI: 1.307‐3.583), having least or highest action arm tremor (OR = 2.512, 95% CI: 1.520‐4.151), having higher score of sleep/fatigue domain (OR = 1.692, 95% CI: 1.004‐2.850) and mood/apathy (OR = 1.926, 95% CI: 1.143‐3.246) domain, to be independently associated with MT manifestation. Conclusions: Our study demonstrates the heterogeneity of symptoms in ET patients with MT, especially in prominent NMS. In addition, the discrepancy of NMS between patients with, and without MT provides novel insight into the underlying pathophysiology and therapeutic of ET. [ABSTRACT FROM AUTHOR]

Background: Deep brain stimulation (DBS) of the posterior subthalamic area (PSA) provides a potentially effective treatment for medication-refractory essential tremor (ET). Objective: To study the clinical benefits and adverse-event profile of bilateral PSA-DBS for refractory ET. Methods: Seven patients with refractory ET underwent bilateral PSA-DBS surgery under general anesthesia between September 2017 and May 2018. Clinical outcome assessments, using the Essential Tremor Rating Scale, were performed at 1-, 6-, and 12-month follow-up, except for the last assessment of one patient who was followed up to 9 months. Analysis was focused on changes in patients' motor symptoms and quality of life following surgery as well as documenting the adverse-event profile associated with the surgical PSA-DBS treatment. Results: After surgery, patients' motor symptoms, including upper limb tremor and head tremor, were improved by 84.2% and their quality of life by 81.25% at 1-month follow-up. The clinical benefits to patients were maintained at 6-month and last follow-up. Adverse side effects included dysarthria (n = 4), balance disorder (n = 2), and paresthesia of the right limb (n = 1). No habituation effects were observed throughout the follow-up. Conclusion: Bilateral PSA-DBS seems to offer an effective and safe alternative treatment for medically intractable ET, warranting further research into its clinical utility, adverse-event profile, and comparative effectiveness. [ABSTRACT FROM AUTHOR]

Neuropathic tremors are often encountered in both hereditary as well as acquired inflammatory demyelinating neuropathies, such as IgM paraproteinemic neuropathy and chronic inflammatory demyelinating polyradiculoneuropathy and occasionally during the recovery phase of Guillain-Barré syndrome (GBS). Acute motor axonal neuropathy (AMAN) accounts for up to 30–65% the patients with GBS in East Asia and is rarely associated with a neuropathic tremor. We report a patient with AMAN, who presented with pure motor quadriplegia with bulbar symptoms and a prominent atypical resting head tremor during the acute phase of illness, which showed an excellent response to topiramate therapy.

In addition to having postural and kinetic tremor of the upper limbs, some patients with essential tremor (ET) may have head tremor as well as cognitive and psychiatric disorders. We aimed to investigate whether the variable clinical presentation in ET patients, including motor and non-motor symptoms, differs in patients with and without head tremor. We consecutively enrolled 70 patients with a diagnosis of ET. Tremor severity was assessed by means of clinical rating scales. Patients also underwent kinematic recordings of postural and kinetic tremor of the upper limbs based on an optoelectronic system. Several neuropsychological tests were also administered. Finally, we adopted the structured interviews for DSM-IV, SCID-I, and SCID-II to investigate psychiatric and personality disorders. ET patients with upper limb tremor plus head tremor exhibited more severe kinetic tremor of the upper limbs and a higher occurrence of axis I psychiatric disorders than ET patients with upper limb tremor only. Cognitive and other motor and psychiatric features did not differ significantly with respect to tremor distribution. The study findings support the hypothesis that body tremor distribution, i.e., the presence of head tremor, influences the variable clinical presentation of ET. The study results support the notion that cases with head tremor may represent a distinct ET subtype, characterized by a prominent cerebellar involvement, and that psychiatric disorders should be considered as a specific manifestation of ET. [ABSTRACT FROM AUTHOR]

Introduction: Dystonia is often associated with repetitive jerky oscillations (i.e. dystonic tremor), while tremor is characterized by sinusoidal oscillations. We propose two competing predictions for dystonic tremor and sinusoidal tremor relationship. In any given patient, (1) the oscillation could be characterized as either sinusoidal or jerky based on the degree of distortion in the waveforms, (2) the oscillation consists of both sinusoidal and jerky waveforms mixed in a certain proportion that varies among individuals. We objectively test these predictions in patients with cervical dystonia.Methods: We recorded head oscillations in 14 subjects with cervical dystonia using a high-resolution magnetic field search coil system. Distortion in the signal was used as a measure of jerkiness. A hierarchical clustering classified the oscillations based on distortion characteristics.Results: Signal analysis in the frequency domain allowed identification of the components of the waveforms at frequencies other than the fundamental frequency. The distortion from the component at fundamental frequency was present in both low and high frequency range. Based on varying levels of distortions, i.e. jerkiness, the head oscillations were grouped into 4 clusters: one cluster with lowest distortion (sinusoidal waveforms), one cluster with highest distortion (jerky waveforms), and two intermediate clusters - one with distortion at low frequency and another with distortion at high frequency. The distribution of 4 clusters varied across subjects suggesting co-existence of sinusoidal and jerky waveforms.Conclusion: These results support the prediction that jerky and sinusoidal waveforms concur in cervical dystonia. Amount of concurrence varies amongst patients. [ABSTRACT FROM AUTHOR]

Background: Cervical dystonia (CD) can present with head tremor. It is unclear whether ataxic features are differentially associated with this phenotype at onset of CD. Objectives: We sought to evaluate: (1) the demographic features of CD patients with (Tr-CD) and without head tremor (nTr-CD) at onset, and (2) the differential ataxic features between these CD subtypes. Methods: For the first objective, we compared demographic data in Tr-CD versus nTr-CD subtypes in the entire cohort of CD subjects enrolled in the Dystonia Coalition Natural History and Biorepository studies (n = 1608). For the second objective, we rated the standardized videos from consecutively enrolled Tr-CD subjects (n = 50) and age-, gender-, and disease duration-matched nTr-CD subjects (n = 50) for ataxia severity scoring using the Scale for the Assessment and Rating of Ataxia (SARA) and the International Cooperative Ataxia Rating Scale (ICARS); and for dystonia severity using the Toronto Western Spasmodic Torticollis Rating Scale section-I (TWSTRS) and the Global Dystonia Rating Scale (GDRS). Results: Of 1,608 subjects, 18.1% (n = 291) were classified as Tr-CD and 81.9% (n = 1317) as nTr-CD. The Tr-CD cohort was older, predominantly female, and had longer disease duration than the nTr-CD cohort (p = 0.01). Compared to nTr-CD, Tr-CD subjects had worse generalized ataxia, speech, and gait and posture scores. High ataxia severity with low dystonia severity distinguished Tr-CD from nTr-CD with high accuracy (area under the curve, 0.91 (95% CI 0.85–0.97). Conclusions: Head tremor at disease onset represents a clinically distinguishable subtype of cervical dystonia affecting predominantly older women, with worse ataxia and milder dystonia than the non-tremulous dystonic phenotype. [ABSTRACT FROM AUTHOR]

Abstract Dystonia is the third most common movement disorder affecting three million people worldwide. Cervical dystonia is the most common form of dystonia. Despite common prevalence the pathophysiology of cervical dystonia is unclear. Traditional view is that basal ganglia is involved in pathophysiology of cervical dystonia, while contemporary theories suggested the role of cerebellum and proprioception in the pathophysiology of cervical dystonia. It was recently proposed that the cervical dystonia is due to malfunctioning of the head neural integrator – the neuron network that normally converts head velocity to position. Most importantly the neural integrator model was inclusive of traditional proposal emphasizing the role of basal ganglia while also accommodating the contemporary view suggesting the involvement of cerebellum and proprioception. It was hypothesized that the head neural integrator malfunction is the result of impairment in cerebellar, basal ganglia, or proprioceptive feedback that converge onto the integrator. The concept of converging input from the basal ganglia, cerebellum, and proprioception to the network participating in head neural integrator explains that abnormality originating anywhere in the network can lead to the identical motor deficits – drifts followed by rapid corrective movements – a signature of neural integrator dysfunction. We tested this hypothesis in an experiment examining simultaneously recorded globus pallidal single-unit activity, synchronized neural activity (local field potential), and electromyography (EMG) measured from the neck muscles during the standard-of-care deep brain stimulation surgery in 12 cervical dystonia patients (24 hemispheres). Physiological data were collected spontaneously or during voluntary shoulder shrug activating the contralateral trapezius muscle. The activity of pallidal neurons during shoulder shrug exponentially decayed with time constants that were comparable to one measured from the pretectal neural integrator and the trapezius electromyography. These results show that evidence of abnormal neural integration is also seen in globus pallidum, and that latter is connected with the neural integrator. Pretectal single neuron responses consistently preceded the muscle activity; while the globus pallidum internus response always lagged behind the muscle activity. Globus pallidum externa had equal proportion of lag and lead neurons. These results suggest globus pallidum receive feedback from the muscles or the efference copy from the integrator or the other source of the feedback. There was bi-hemispheric asymmetry in the pallidal single-unit activity and local field potentials. The asymmetry correlated with degree of lateral head turning in cervical dystonia patients. These results suggest that bihemispheric asymmetry in the feedback leads to asymmetric dysfunction in the neural integrator causing head turning. Highlights • Integrative network of brainstem, cerebellum, and basal ganglia can cause dystonia. • Integration is changing dynamic signal to steady-state discharge. • Discharge property of the basal ganglia output reflect abnormal neural integration. • Basal ganglia abnormality is secondary, due to impaired network feedback. [ABSTRACT FROM AUTHOR]

Background: Directional, deep-brain stimulation may prove beneficial for targets (1) thinner along the lead trajectory, and (2) whose borders are not easily visible by neuroimaging. When targeting the ventral intermediate (VIM) nucleus of the thalamus for essential tremor, even baseline ataxia may be exacerbated by medial spread of current and antidromic stimulation of vestibular-cerebellar-thalamic afferents. Case Report: The present patient with essential tremor developed refractory head tremor leading to implantation of bilateral St. Jude/Abbott segmented leads into the VIM to afford additional programming options. Discussion: Video evidence showed that directional stimulation did not exacerbate ataxia beyond baseline, whereas nondirectional stimulation exacerbated ataxia consistently. We discuss how this programming advantage may help address a common complication from DBS implantation for essential tremor patients. [ABSTRACT FROM AUTHOR]

Head tremor is a common symptom of essential tremor (ET) and cervical dystonia (CD). In clinical practice, it is often difficult to distinguish between these two conditions, especially in cases where head tremor predominates. To investigate which clinical and instrumental methods best differentiate ET and CD in patients with head tremor. 65 patients were included, of which 23 were diagnosed with ET and head tremor (HT+), 21 with ET without head tremor (HT-) and 21 with CD and dystonic head tremor. 22 healthy volunteers served as controls. All patients were examined using the rating scales for ET (TETRAS), cervical dystonia (TWSTRS), and ataxia (SARA). The Somatosensory Temporal Discrimination Threshold (STDT) was defined as the shortest interval in which an individual recognizes two tactile stimuli as temporally separated. TETRAS and SARA scores were higher in the HT+ group compared with HT- and CD, with no significant difference between mild head tremor subscores in HT+ and CD. In most HT+ and CD patients, head tremor disappeared supine. The STDT values were significantly higher in the HT+ group compared with controls. While TWSTRS contributed to assess dystonia severity, the scales of tremor and ataxia were not helpful in differentiating head tremor syndromes. The cessation of head tremor in the supine position could be related to the overall mild head tremor scores in both groups. Increased SARA scores and STDT values in HT+ patients suggest a possible role of cerebellar involvement and altered somatosensory timing that merit further verification. • While TWSTRS assessed dystonia, scales of tremor and ataxia failed to differentiate essential and dystonic head tremors. • Head tremor (HT) stopped in the supine resting position in nearly all patients with mild essential and dystonic HT. • Essential tremor (ET) patients with HT exhibited higher scores on the scale of ataxia, compared to ET patients without HT. • Somatosensory temporal discrimination threshold was not useful in distinguishing essential HT from cervical dystonic HT. [ABSTRACT FROM AUTHOR]

Tremors are commonly encountered in clinical practice and are the most common movement disorders seen. It is defined as a rhythmic, involuntary oscillatory movement of a body part around one or more joints. In the majority of the population, tremor tends to be mild. They have varying etiology; hence, classifying them appropriately helps in identifying the underlying cause. Clinically, tremor is classified as occurring at rest or action. They can also be classified based on their frequency, amplitude, and body part involved. Parkinsonian tremor is the most common cause of rest tremor. Essential tremor (ET) and enhanced physiological tremor are the most common causes of action tremor. Isolated head tremor is more likely to be dystonic rather than ET. Isolated voice tremor could be considered to be a spectrum of ET. Psychogenic tremor is not a diagnosis of exclusion; rather, demonstration of various clinical signs is needed to establish the diagnosis. Severity of tremor and response to treatment can be assessed using clinical rating scales as well as using electrophysiological measurements. The treatment of tremor is symptomatic. Medications are effective in half the cases of essential hand tremor and in refractory patients; deep brain stimulation is an alternative therapy. Midline tremors benefit from botulinum toxin injections. It is also the treatment of choice in dystonic tremor and primary writing tremor.

Keywords: Spastic ataxia; SPG46; GBA2; Head tremor; Dystonia EN Spastic ataxia SPG46 GBA2 Head tremor Dystonia 13 15 3 01/09/21 20210101 NES 210101 Hereditary spastic paraplegias (HSP) are a clinically and genetically heterogenous group of neurodegenerative disorders. Both our cases had a typical presentation of SPG46 with progressive spastic ataxic syndrome and cerebellar atrophy except for the head tremor, cervical and UL dystonia in case-1 and UL dystonia in case -2. Dystonia in SPG46 has also been rarely reported, with one case each of cervical with jaw opening dystonia, cervical with upper limb dystonia [[5]], and isolated cervical dystonia [[3]]. [Extracted from the article]

Head tremor usually requires bilateral deep brain stimulation of ventralis intermedius nucleus of thalamus. Ablation of VIM nucleus (VIM thalamotomy) is applied for limb tremor unilaterally because of serious complications from bilateral thalamotomy. Therefore, effects of thalamotomy on head tremor have been rarely reported. We report a successful long‐term outcome of head tremor with combined unilateral VIM thalamotomy and contralateral VIM‐DBS simultaneously. The patient was a 49‐year‐old man with head and bilateral hand tremors. His Fahn‐Tolosa‐Marin Tremor Rating Scale scores (head tremor score, range 8‐0, higher scores indicate greater severity) before and after the surgery were 8 and 0, respectively. Only transient tongue numbness was confirmed as a surgical complication. At the final follow‐up (36 months), the patient was completely free from tremor of the head and bilateral hands. Combined thalamotomy and DBS can be an alternative treatment option for head tremor. [ABSTRACT FROM AUTHOR]

Background: Mild and transient head tremor may sometimes be observed in otherwise tremor-free relatives of essential tremor (ET) cases, although its prevalence is unclear. A diagnostic question is whether this transient, isolated head tremor, often observed as no more than a wobble, is an early manifestation of ET or whether it is a normal finding. A direct comparison with controls is needed.Methods: Two hundred and forty-one first-degree relatives of ET cases (FD-ET) and 77 spousal controls (Co) were enrolled in a study of ET. Each underwent a detailed evaluation that included a tremor history and videotaped neurological examination. None of the enrollees reported tremor, had a prior diagnosis of ET, or had significant tremor on screening spirals. All videotaped examinations were initially reviewed by a movement disorder neurologist blinded to subject type, and among those with head tremor on examination, co-reviewed by two additional movement disorders neurologists.Results: Twenty-six (10.8, 95% Confidence interval [CI] = 7.5–15.3%) of 241 FD-ET vs. 2 (2.6, 95% CI = 0.7–9.0%) of 77 Co had isolated, transient head tremor (odds ratio = 4.54, 95% CI = 1.05–19.57, p = 0.04). No enrollee had significant upper extremity tremor and none met inclusion criteria for ET based on the presence of upper extremity tremor. With one exception, head tremor occurred during or after phonation. It was always transient (generally a single back and forth wobble) and rare (observed briefly on one or two occasions during the videotaped examination) and had a faster frequency, lower amplitude and a different quality than voluntary head shaking.Conclusion: The basis for the observed isolated head tremor is unknown, but it could be an early feature of ET in ET families.Indeed, one-in-ten otherwise unaffected first-degree relatives of ET cases exhibited such tremor. To a far lesser extent it was also observed in “unaffected” controls. In both, it is likely a sign of early, emerging, undiagnosed ET, although follow-up studies are needed to confirm this. If it were ET, it would indicate that the prevalence of ET may be considerably higher than previously suspected.

Acquired periodic alternating nystagmus (PAN) describes a horizontal jerk nystagmus that reverses its direction with a predictable cycle, and is thought to arise from lesions involving the brainstem and cerebellum. We report a 20-year-old patient with PAN who presented with an acute vertiginous episode and developed an involuntary head movement that initially masked the PAN. The involuntary head movements were abolished with a subtherapeutic dose of botulinum toxin to the neck muscles. We propose that the head movements initially developed as a compensatory movement to the nystagmus, to maintain visual fixation in the presence of the underlying nystagmus, and became an entrained involuntary behavior. This case highlights the importance of disambiguating psychogenic from organic pathology as this may have clinical therapeutic implications, in this case resolution of the most disabling symptom which was her head oscillations, leading to improved day-to-day function despite PAN.

Propranolol is used as the first-line treatment in essential tremor and it has also been proposed as a treatment for tremor in dystonia. However, several issues remain uncertain. For example, it is still not clear whether propranolol exerts a beneficial effect on head tremor. Moreover, no studies have investigated whether the effect of propranolol on head and upper limb tremor in essential tremor differs from that in dystonia. We aimed to assess the effects of propranolol on tremor in different body parts in essential tremor and in patients with tremor and dystonia. Twenty-nine patients with head and upper limb tremor were enrolled in the study, 14 with essential tremor, and 15 with dystonia. Participants underwent a clinical and kinematic analysis of tremor in two sessions, i.e., without (baseline) and ‘on therapy’ with propranolol. We found that head tremor was more severe in patients with dystonia, while upper limb tremor was more evident in patients with essential tremor (P < 0.05). Propranolol had no effect on head tremor in either group (all Ps > 0.05), but it did reduce upper limb tremor in patients with essential tremor. The present study demonstrates differential effects of propranolol on head and upper limb tremor in patients with essential tremor. The lack of effect on head and upper limb tremor in patients with dystonia suggests that the pathophysiological mechanisms underlying tremor in these two conditions and in different body parts may be distinct. [ABSTRACT FROM AUTHOR]

Background: Mild and transient head tremor may sometimes be observed in otherwise tremor-free relatives of essential tremor (ET) cases, although its prevalence is unclear. A diagnostic question is whether this transient, isolated head tremor, often observed as no more than a wobble, is an early manifestation of ET or whether it is a normal finding. A direct comparison with controls is needed. Methods: Two hundred and forty-one first-degree relatives of ET cases (FD-ET) and 77 spousal controls (Co) were enrolled in a study of ET. Each underwent a detailed evaluation that included a tremor history and videotaped neurological examination. None of the enrollees reported tremor, had a prior diagnosis of ET, or had significant tremor on screening spirals. All videotaped examinations were initially reviewed by a movement disorder neurologist blinded to subject type, and among those with head tremor on examination, co-reviewed by two additional movement disorders neurologists. Results: Twenty-six (10.8, 95% Confidence interval [CI] = 7.5-15.3%) of 241 FD-ET vs. 2 (2.6, 95% CI = 0.7-9.0%) of 77 Co had isolated, transient head tremor (odds ratio=4.54, 95%CI=1.05-19.57, p=0.04). No enrollee had significant upper extremity tremor and none met inclusion criteria for ET based on the presence of upper extremity tremor. With one exception, head tremor occurred during or after phonation. It was always transient (generally a single back and forth wobble) and rare (observed briefly on one or two occasions during the videotaped examination) and had a faster frequency, lower amplitude and a different quality than voluntary head shaking. Conclusion: The basis for the observed isolated head tremor is unknown, but it could be an early feature of ET in ET families.Indeed, one-in-ten otherwise unaffected first-degree relatives of ET cases exhibited such tremor. To a far lesser extent it was also observed in "unaffected" controls. In both, it is likely a sign of early, emerging, undiagnosed ET, although follow-up studies are needed to confirm this. If it were ET, it would indicate that the prevalence of ET may be considerably higher than previously suspected. [ABSTRACT FROM AUTHOR]

Acquired periodic alternating nystagmus (PAN) describes a horizontal jerk nystagmus that reverses its direction with a predictable cycle, and is thought to arise from lesions involving the brainstem and cerebellum. We report a 20-year-old patient with PAN who presented with an acute vertiginous episode and developed an involuntary head movement that initially masked the PAN. The involuntary head movements were abolished with a subtherapeutic dose of botulinum toxin to the neck muscles. We propose that the head movements initially developed as a compensatory movement to the nystagmus, to maintain visual fixation in the presence of the underlying nystagmus, and became an entrained involuntary behavior. This case highlights the importance of disambiguating psychogenic from organic pathology as this may have clinical therapeutic implications, in this case resolution of the most disabling symptom which was her head oscillations, leading to improved day-to-day function despite PAN. [ABSTRACT FROM AUTHOR]

The identification of ocular tremor in a small cohort of patients with Parkinson’s disease (PD) had lay somewhat dormant until the recent report of a pervasive ocular tremor as a universal finding in a large PD cohort that was, however, generally absent from a cohort of age-matched healthy subjects. The reported tremor had frequency characteristics similar to those of PD limb tremor, but the amplitude and frequency of the tremor did not correlate with clinical tremor ratings. Much controversy ensued as to the origin of such a tremor, and specifically as to whether a pervasive ocular tremor was a fundamental feature of PD, or rather a compensatory eye oscillation secondary to a transmitted head tremor, and thus a measure of a normal vestibulo-ocular reflex. In this mini review, we summarize some of the evidence for and against the case for a pervasive ocular tremor in PD and suggest future experiments that may help resolve these conflicting opinions.