Arm Tremor Research Articles

Successful Therapy of Holmes Tremor with a Silicone Hand-Wrist Orthesis and Botulinum Toxin A

Background: We report a 15-year-old boy, who had a cerebral bleeding in the thalamus and basal ganglia area with a consecutive hemiparesis. The patient suffered from a persisting weakness of underarm and hand and a increasing intention and postural tremor of the whole arm (Holmes tremor). In the tremor analysis, we saw a tremor of low frequency and high amplitude, especially of the upper arm (abduction/elevation) and the hand/dorsal extension/palmar flexion). The hand could not be stabilized—causing a loss of hand function. The tremor was trigged by the “trembling” wrist.

Quantification of sound instability in embouchure tremor based on the time-varying fundamental frequency.

Task-specific tremor in musicians is an involuntary oscillating muscular activity mostly of the hand or the embouchure, which predominantly occurs while playing the instrument. In contrast to arm or hand tremors, which have been examined and objectified based on movement kinematics and muscular activity, embouchure tremor has not yet been investigated. To quantify and describe embouchure tremor we analysed sound production and investigated the fluctuation of the time-varying fundamental frequency of sustained notes. A comparison between patients with embouchure tremor and healthy controls showed a significantly higher fluctuation of the fundamental frequency for the patients in the high pitch with a tremor frequency range between 3 and 8Hz. The present findings firstly provide further information about a scarcely described movement disorder and secondly further evaluate a new quantification method for embouchure tremor, which has recently been established for embouchure dystonia.

Rest tremor in idiopathic adult-onset dystonia.

Tremor in dystonia has been described as a postural or kinetic abnormality. In recent series, however, patients with idiopathic adult-onset dystonia also displayed rest tremor. The frequency and distribution of rest tremor were studied in a cohort of 173 consecutive Italian patients affected by various forms of idiopathic adult-onset dystonia attending our movement disorder clinic over 8 months. Examination revealed tremor in 59/173 patients (34%): 12 patients had head tremor, 34 patients had arm tremor, whilst 13 patients presented tremor in both sites. Head tremor was postural in all patients, whereas arm tremor was postural/kinetic in 28 patients, only at rest in one and both postural/kinetic and at rest in 18 patients. Patients with tremor were more likely to have segmental/multifocal dystonia. Patients who had rest tremor (either alone or associated with action tremor) had a higher age at dystonia onset and a greater frequency of dystonic arm involvement than patients with action tremor alone or without tremor. Both action and rest tremor are part of the tremor spectrum of adult-onset dystonia and are more frequently encountered in segmental/multifocal dystonia. The higher age at dystonia onset and the greater frequency of arm dystonia in patients with rest tremor may have pathophysiological implications and may account, at least in part, for the previous lack of identification of rest tremor as one possible type of tremor present in dystonia.

Comparison of motor and non-motor features between essential tremor and tremor dominant Parkinson's disease

BackgroundDifferential diagnosis of tremor disorders, including essential tremor (ET) and Parkinson's disease-tremor dominant type (PD-TDT), requires further investigation. Therefore, the current study aimed to compare non-motor and tremor features in order to differentiate between ET and PD-TDT. MethodsTwenty-eight patients with classic ET and 24 patients with typical PD-TDT were retrospectively enrolled in a multi-stage investigation process. Tremor features including surface electromyogram (EMG) were analyzed in detail. For non-motor symptom analyses, the global cognition test, frontal function test, and non-motor symptoms scale (NMSS) were administered, in addition to collecting patient history data. ResultsPatients with PD-TDT presented with more asymmetric tremor, whereas patients with ET presented with more symmetric tremor. Leg tremor was observed only in patients with PD-TDT. Surface EMG analyses of arm tremor demonstrated considerable overlaps in tremor type, tremor frequency, and contractive patterns. However, patients with PD-TDT were significantly more likely to exhibit resting tremor, and experienced alternative contraction patterns only for kinetic tremor, which was in contrast to patients with ET. For non-motor symptom analyses, patients with PD-TDT had more non-motor symptoms compared to patients with ET (mean=5.0 vs. 2.6; P=0.002). Specifically, patients with PD-TDT exhibited higher frequencies of hyposmia, REM sleep behavior disorder (RBD)-like symptom, urinary frequency, and memory disturbance. Age- and gender- matched analyses for the severity of NMSS scores did not indicate significant differences. However, patients with PD-TDT displayed slightly lower scores of frontal function test compared to patients with ET. ConclusionsCareful and detailed evaluations of both tremor features and non-motor symptoms are required in order to distinguish between ET and PD-TDT.

Prenatal exposure to the organophosphate pesticide chlorpyrifos and childhood tremor

BackgroundThe organophosphate insecticide chlorpyrifos (CPF), widely used for agricultural purposes, has been linked to neurodevelopmental deficits. Possible motor effects at low to moderate levels of exposure have not been evaluated. MethodsPrenatal exposure to CPF was measured in umbilical cord blood in a sample of 263 inner-city minority children, who were followed prospectively. At approximately 11 years of age (mean age 10.9±0.85 years, range=9.0–13.9), during a neuropsychological assessment, children were asked to draw Archimedes spirals. These were rated by a senior neurologist specializing in movement disorders who was blind to CPF exposure level. ResultsCompared to all other children, those with prenatal CPF exposure in the upper quartile range (n=43) were more likely to exhibit mild or mild to moderate tremor (≥1) in either arm (p=0.03), both arms (p=0.02), the dominant arm (p=0.01), and the non-dominant arm (p=0.055). Logistic regression analyses showed significant CPF effects on tremor in both arms, either arm, the dominant arm (p-values <0.05), and the non-dominant arm (p=0.06), after adjustment for sex, age at testing, ethnicity, and medication. ConclusionPrenatal CPF exposure is associated with tremor in middle childhood, which may be a sign of the insecticide's effects on nervous system function.

Tremor in Charcot-Marie-Tooth disease: No evidence of cerebellar dysfunction

ObjectivesTremor in Charcot-Marie-Tooth disease (CMT) can be disabling. Cerebellar abnormalities are thought to underpin neuropathic tremor. Here, we aim to clarify the potential role of the cerebellum in CMT tremor. MethodsWe assessed prevalence of tremor by questionnaire in 84 patients with CMT. Of those, 23 patients with CMT with and without arm tremor and healthy controls underwent a clinical assessment, classical eyeblink conditioning, electro-oculography, visuomotor adaptation test, tremor recording with surface EMG and accelerometry, and retrospective correlation with nerve conduction studies to investigate the possible mechanisms of tremor generation. ResultsThe prevalence study revealed tremor in 21% of patients and in 42% of those it caused impairment of function. Tremor recordings revealed a mild-to-moderate amplitude tremor with a weight load-invariant 7.7Hz frequency component. Performance on classical eyeblink conditioning, visuomotor adaptation and electro-oculography were no different between tremulous and non-tremulous patients and healthy controls. ConclusionsThese results argue against a prominent role for an abnormal cerebellum in tremor generation in the patients studied with CMT. Rather, our results suggest an enhancement of the central neurogenic component of physiological tremor as a possible mechanism for tremor in the patients studied. SignificanceThis study is the first to propose differing pathogenic mechanisms for subtypes of neuropathic tremor.

5.: Dystonic features are common in multiple sclerosis-related tremor and contribute to its severity

Detailed phenomenological studies are needed to characterize multiple sclerosis (MS)-related tremor and investigate factors that may predict its severity. We completed a detailed, blinded study in order to define clinical features that may be unique to MS tremor patients and that may inform the underlying pathophysiology of MS tremor. The objectives of this study were to investigate clinical factors that contribute to tremor severity in patients with MS, and to determine if dystonia is more common in MS tremor patients than disease-matched, non-tremor controls. We recruited 54 MS patients with and without disabling arm tremor matched for age, sex and disability. Both limbs were assessed in bilateral tremor, resulting in 39 limbs per group. Cerebellar function was rated with the Scale for the Assessment and Rating of Ataxia. Assessments of tremor severity (Bain score for tremor severity, writing and drawing) and dystonia (Global Dystonia Scale [GDS] for proximal and distal arms) using video and handwriting recordings were completed. All samples were shuffled and rated by a blinded movement disorder expert. The presence and severity of dystonic posturing, mirror movements and geste antagonistes were scored. We found associations ( p p p p = 0.022) increase in tremor severity and a 1 unit ( p = 0.001) increase in drawing scores. One unit increase in proximal GDS predicted a 0.93 unit increase ( p p = 0.050) increase in writing scores and a 1.5 unit ( p = 0.002) increase in drawing score. The results of this study demonstrate the importance of recognizing dystonia as part of the complex movement disorder that represents MS tremor. The presence of dystonia points to injury in the cerebello-pallido-thalamo-cortical network and could explain the efficacy of onabotulinumtoxin-A therapy in the treatment of MS tremor.

Patients with scans without evidence of dopaminergic deficit: a long-term follow-up study.

We previously reported on a cohort of dystonic tremor and patients with scans without evidence of dopaminergic deficit (SWEDDs). We aim to report the long-term clinical and imaging follow-up of these patients. Patients with at least 5-year follow-up were included. These patients had an asymmetric arm tremor, a previous diagnosis of Parkinson's disease (PD), and a subsequent normal DaTscan. The imaging and clinical follow-up was done on the clinical basis. Sixteen patients were included. The mean gap between the first and subsequent scans was 5.4 years. Two patients (12.5%) had reduced nigrostriatal uptake on follow-up DaTscan, whereas 14 continued to have normal dopaminergic imaging. This is the longest follow up of patients with asymmetric rest tremor and normal DaT scans (SWEDDs) reported to date. We show here that only a minority of them show reduced striatonigral uptake over long term follow up.

Intention Tremor of the Legs in Essential Tremor: Prevalence and Clinical Correlates.

To estimate the prevalence and assess the clinical correlates of intention tremor in the legs in essential tremor (ET) patients. The cerebellar features of ET are of growing interest to clinical neurologists. Arm tremor has an intentional component in many ET patients. Intention tremor in the legs, however, has never been systematically evaluated. One-hundred-twenty-eight ET patients were enrolled in a clinical-epidemiological study at Columbia University. A videotaped neurological examination included 10 toe-to-target movements with each foot. Videotapes were independently reviewed by two movement disorder neurologists who noted the presence vs. absence of intentional leg tremor. Two patients underwent quantitative computerized tremor analysis to study the physiological characteristics of the tremor. Thirty-five patients (27.3%) had intentional leg tremor; in 21, tremor was unilateral and in 14 it was bilateral. The 35 patients with intentional leg tremor did not differ from the remaining 93 patients in their clinical characteristics. Analyses comparing the 14 patients with bilateral intentional leg tremor to the 93 patients with no intentional leg tremor showed trends towards longer disease duration and more severe intentional arm tremor in the former. Tremor analysis showed a 3-fold increase in average tremor amplitude from movement onset to the point just prior to touching the target. Our data suggest that intentional leg tremor, another cerebellar feature, is common in ET patients. The tremor may be associated with longer disease duration and more severe intentional arm tremor, but these preliminary trends need to be assessed in larger study samples.

Head and Arm Tremor in X-linked Spinal and Bulbar Muscular Atrophy

Head and Arm Tremor in X-linked Spinal and Bulbar Muscular Atrophy

Head and Arm Tremor in X-linked Spinal and Bulbar Muscular Atrophy.

BackgroundX-linked spinal and bulbar muscular atrophy (SBMA) is a rare adult-onset neuronopathy. Although tremor is known to occur in this disease, the number of reported cases of SBMA with tremor is rare, and the number with videotaped documentation is exceedingly rare. Our aim was to describe/document the characteristic signs of tremor in spinal and bulbar muscular atrophy.Case ReportWe report a case of a 58-year-old male with a positive family history of tremor. On examination, the patient had jaw and hand tremors but he also exhibited gynecomastia, progressive bulbar paresis, and wasting and weakness primarily in the proximal limb muscles. The laboratory tests revealed an elevated creatine phosphokinase. Genetic testing was positive for X-SBMA, with 42 CAG repeats.DiscussionEssential tremor is one of the most common movement disorders, yet it is important for clinicians to be aware of the presence of other distinguishing features that point to alternative diagnoses. The presence of action tremor associated with muscle atrophy and gynecomastia should lead to a suspicion of SBMA.

Orthostatic tremor: a review of 45 cases.

To evaluate the clinical characteristics, associated features, and treatment response of a large orthostatic tremor series seen over a 26-year period. We reviewed the medical records of 45 patients seen between 1987 and 2013 who fulfilled the diagnostic criteria for orthostatic tremor. The mean age at onset was 59.5 years and 23/45 (51%) were men. A family history of any tremor was noted in 23/45 (51%) patients. A family history of orthostatic tremor was reported in 3/45 (7%) patients. 40/45 (89%) had primary orthostatic tremor with (n = 30) or without (n = 10) an associated postural arm tremor. We found that 5/45 (11%) had orthostatic tremor plus additional neurological features. One patient was diagnosed with dementia with Lewy bodies preceded by orthostatic tremor for 20 years. Prospective follow-up data was available for 30/45 patients and averaged 54.4 months. Treatment response to medications was modest and inconsistent. In 11/30 cases, orthostatic tremor worsened over the follow-up period. One patient with primary orthostatic tremor underwent thalamic deep brain stimulation surgery. In our population of orthostatic tremor patients, mild postural hand tremor was a frequent finding. Over half of our patients had a family history of tremor, but a family history of orthostatic tremor was uncommon. Additional neurological features were seen in the minority of patients and we report possibly the first case of dementia with Lewy bodies associated with orthostatic tremor. Our series is the largest series of orthostatic tremor reported in the literature and contributes to understanding the clinical characteristics of this rare disease.

Essential tremor suppression by a novel self-balancing device

There are many associated devices using impedance method. However, they cannot completely suppress tremor. Other methods using active vibration control have been a challenging problem for industrial and academic researchers. Potential applications of the latter for tremor patients are still not realized. This article presents a novel method for suppressing human lower arm tremor in essential tremor by using a self-balancing technique. In this article, a rotating unbalanced mass actuator was used to imitate an arm tremor with the same frequency range obtained from clinical sources. A novel counter-balance device was designed to attach the fictitious arm. The tremor reduction is expecting quantitatively. A Proportional-Integral-Derivative controller and an algorithm programmed in LabVIEW are proposed to control a rotating unbalanced mass actuator, anti-shaker, in order to counter the tremor. The self-balancing system for the new approach was obtained when both amplitudes and frequencies of anti-shaker and tremor are the same. The results show that this method can reduce vibration of tremor in the order of 0.001 rad/s(2). This method can suppress the vibration and can also auto-tune to counter the tremor in a range of 4-12 Hz bandwidth. The therapy of arm tremor was associated with using counter-devices to palliate the vibration magnitude. Conventional methods such as physical surgery and drugs cannot completely eliminate tremor. The novel counter-device is an alternative technique with promising application for clinical uses for tremor patients without involving harmful surgery.

The phenotypic spectrum of DYT24 due to ANO3 mutations

Genes causing primary dystonia are rare. Recently, pathogenic mutations in the anoctamin 3 gene (ANO3) have been identified to cause autosomal dominant craniocervical dystonia and have been assigned to the dystonia locus dystonia-24 (DYT24). Here, we expand on the phenotypic spectrum of DYT24 and provide demonstrative videos. Moreover, tremor recordings were performed, and back-averaged electroencephalography, sensory evoked potentials, and C-reflex studies were carried out in two individuals who carried two different mutations in ANO3. Ten patients from three families are described. The age at onset ranged from early childhood to the forties. Cervical dystonia was the most common site of onset followed by laryngeal dystonia. The characteristic feature in all affected individuals was the presence of tremor, which contrasts DYT24 from the typical DYT6 phenotype. Tremor was the sole initial manifestation in some individuals with ANO3 mutations, leading to misdiagnosis as essential tremor. Electrophysiology in two patients with two different mutations showed co-contraction of antagonist muscles, confirming dystonia, and a 6-Hz arm tremor at rest, which increased in amplitude during action. In one of the studied patients, clinically superimposed myoclonus was observed. The duration of the myoclonus was in the range of 250 msec at about 3 Hz, which is more consistent with subcortical myoclonus. In summary, ANO3 causes a varied phenotype of young-onset or adult-onset craniocervical dystonia with tremor and/or myoclonic jerks. Patients with familial cervical dystonia who also have myoclonus-dystonia as well as patients with prominent tremor and mild dystonia should be tested for ANO3 mutations. © 2014 The Authors. Movement Disorders published by International Parkinson and Movement Disorder Society

Rest and other types of tremor in adult-onset primary dystonia

IntroductionKnowledge regarding tremor prevalence and phenomenology in patients with adult-onset primary dystonia is limited. Dystonic tremor is presumably under-reported, and we aimed to assess the prevalence and the clinical correlates...

Triggering essential head tremor with sustained phonation: A clinical phenomenon with potential diagnostic value

Here we report a clinical phenomenon that we have observed repeatedly in clinical research settings; namely, a triggering and/or exacerbation of head tremor during or immediately following sustained phonation. To our knowledge, it has not been reported previously nor has it been the subject of study. Here we: 1) report the phenomenon, 2) provide several visual illustrations, 3) estimate its prevalence, and 4) analyze its clinical correlates. Head tremor was assessed qualitatively, and scores were assigned pre-, during, and post-sustained phonation using the Tremor Research Group Essential Tremor Rating Assessment Scale. Seventy (68.6%) of 102 essential tremor (ET) patients exhibited a qualitative increase in head tremor amplitude during and/or immediately after sustained phonation; in 5 (4.9%), head tremor would not have been detected without the voice activation maneuver (i.e., it was not visible at any other point in the videotape aside from the period during/immediately following sustained phonation). Women were more likely than men to exhibit this phenomenon (p = 0.05), whereas age, age at onset, duration of tremor, and total tremor score did not predict responsiveness of head tremor to sustained phonation. Sustained voice activation is a useful examination maneuver that may elicit or amplify head tremor in ET. Head tremor is not reported to occur in patients with enhanced physiological tremor. Thus, this maneuver, by triggering head tremor, may be a useful diagnostic supplement, particularly in research/clinical settings where arm tremor is mild and the diagnosis (mild ET vs. enhanced physiological tremor) would otherwise be ambiguous.

Impaired activation of somatosensory cortex as FMRI correlate of reduced dexterity in PD

WCN 2013 No: 1278 Topic: 2 — Movement Disorders Impaired activation of somatosensory cortex as FMRI correlate of reduced dexterity in PD T. Foki, W. Pirker, A. Geissler, D. Haubenberger, M. Hilbert, I. Hoellinger, M. Wurnig, J. Rath, J. Lehrner, S. Trattnig, E. Auff, R. Beisteiner. Department of Neurology, Medical University of Vienna, Vienna, Austria; MR Center of Excellence, Department of Radiology, Medical University of Vienna, Vienna, Austria; Department of Radiology, Medical University of Vienna, Vienna, Austria Background: Previously (1ab), the DOPA-resistant component of decreased dexterity in PD was called limb-kinetic apraxia (LkA). Our recent fMRI pilot study (2) investigating PD patients OFF medication suggested impaired activation of primary somatosensory cortex (SSC) as closely related to LkA. Both in the behavioral (1ab) and FMRI studies (2), coin rotation (CR, LkA task, target condition) was contrasted with simple finger tapping (FT, bradykinesia task, reference condition). FMRI signal changes were hence corrected for basic motor skills and represented activation particularly associated with dexterity. Based on the DOPA resistance of CR performance in (1ab), we hypothesized a reproducibility of impaired activation of the SSC ON medication. Objective: The objective of this study is to confirm dysfunction of SSC as closely related to DOPA-resistant dexterity deficits in PD. Patients and methods: According to the experimental setup (CR vs. FT) mentioned above, 10 PD patients performed the FMRI experiment in the ON as well as the OFF condition. 14 healthy controls performed the same experiment. Patients were compared to controls (SPM8). Results: Confirming our pilot study, we assessed decreased activation of the SSC in patients OFF medication compared to controls. In line with our study hypothesis, this finding was reproducible in patients ON medication compared to controls (p b 0.01, uncorr., k = 25 vox.). Comparing FMRI signals in the SSC between ON and OFF conditions, no differences could be assessed (lowering even to p b 0.05). Conclusions: Dexterity deficits in PD are linked to a dysfunction of the SSC. (1a) Gebhardt-et-al._MovDisord 2008;23 :1701-6. (1b) Quencer-et-al._Neurology 2007;68:150-1. (2) Foki-et-al._ExpNeurol 2010;225:416-22. doi:10.1016/j.jns.2013.07.405 Abstract — WCN 2013 No: 1269 Topic: 2 — Movement Disorders Subjective and objective alcohol responsiveness in different tremor disorders WCN 2013 No: 1269 Topic: 2 — Movement Disorders Subjective and objective alcohol responsiveness in different tremor disorders P. Schwingenschuh, M. Koegl-Wallner, U. Werner, T. Pendl, C. Ghadery, S. Seiler, K. Wenzel, R. Schmidt, P. Katschnig-Winter. Department of Neurology, Medical University of Graz, Graz, Austria Background: A few studies exist on the effect of alcohol in essential tremor (ET) and Parkinson s disease (IPD), but so far no systematic studies have been performed in other tremor syndromes. Nevertheless, a positive response to alcohol – commonly simply inquired by history – is used as supportive diagnostic criterion for ET. Objective: The objective of this study is to investigate if subjective/ objective alcohol responses distinguish a broad range of tremor disorders. Methods: (1) We assessed drinking habits and response of tremor to alcohol intake in 100 consecutive patients with arm tremor. (2) For a double-blind placebo-controlled oral alcohol test we recruited 12 patients with ET, 10 IPD, and 7 dystonic tremor (DT). The effect to alcohol/placebo was assessed at baseline and after 30/ 60/120 min by clinical rating scales and accelerometry. Results: (1) We investigated 44 patients with IPD, 22 ET, 20 DT, and 14 others. Of 77 patients drinking alcohol, 23 had no response, 26 had improvement, and 28 never paid attention. None of the evaluated parameters differed between the groups. (2) ET, IPD, and DT had a significant tremor improvement with placebo and alcohol. There were no significant between group differences. However, in the ET group there was a stronger objective effect of alcohol compared to placebo. Conclusions: Subjective alcohol response inquired by history may not be suitable as supportive diagnostic criterion for ET. Objectively, all investigated patients improved with alcohol. This effect seems to be truly alcohol related in ET only. doi:10.1016/j.jns.2013.07.406 Abstract — WCN 2013 No: 1258 Topic: 2 — Movement Disorders Exome sequencing analysis in familial progressive supranuclear palsy WCN 2013 No: 1258 Topic: 2 — Movement Disorders Exome sequencing analysis in familial progressive supranuclear palsy C. Bettencourt, A. Tucci, R. Ros, J. Lopez-Sendon, J. Hardy, J. Garcia deYebenes,H.Houlden. Department ofMolecularNeuroscience, UCL Institute of Neurology, London, UK; Department of Neurology, Hospital Ramon y Cajal, Madrid, Spain Background: Progressive supranuclear palsy (PSP) is a clinicopathological syndrome characterized by akinesia, supranuclear gaze palsy, Abstracts / Journal of the Neurological Sciences 333 (2013) e109–e151 e121

Unilateral thalamic deep brain stimulation in essential tremor demonstrates long-term ipsilateral effects

IntroductionDeep Brain Stimulation (DBS) of thalamus in essential tremor (ET) is effective for the treatment of contralateral tremors. Bilateral DBS controls tremors on both sides but is associated with increased morbidity and risks. We evaluated if unilateral surgery had ipsilateral benefits on tremors and thus could be a potentially safer alternative to bilateral DBS. MethodsMedication refractory ET patients undergoing unilateral thalamic DBS were included and longitudinally followed. Tremor rating scale was used to record total motor, arm tremor and activities of daily living (ADL) scores at baseline, six months and at last visit (three or more years after surgery). Postoperative scores were recorded with DBS turned OFF and ON. ResultsTwenty-two patients with a mean follow-up 3.4 ± 0.14 years were enrolled. When baseline scores were compared to scores with the DBS turned ON, significant improvements were noted in total tremor (40%), ADL (67%) and arm tremor scores both on the ipsilateral and the contralateral side at six months and at the last visit of follow-up (all p < 0.05). Ipsilateral arm tremor (∼56%) improvements were milder compared to the contralateral side (∼73%) tremors. ConclusionUnilateral thalamic DBS in ET demonstrates significant long-term benefits for ipsilateral arm tremors and can be offered to higher risk and to select patients.

The "head snap": a subtle clinical feature during the finger-nose-finger maneuver in essential tremor.

Essential tremor is characterized by several hyperkinetic movements, including arm and head tremors. We report another movement of the head in patients with essential tremor, which we term the "head snap." This was observed as a jerking motion of the head in some patients while they performed the finger-nose-finger maneuver. We compared the prevalence of the head snap in essential tremor patients vs. Parkinson's disease patients. We also assessed the clinical correlates of the head snap. Ten (20%) of 50 essential tremor patients exhibited a head snap of any severity (rating ≥0.5) vs. 0 of 50 Parkinson's disease patients (p = 0.001). Patients with head snap had more severe arm tremor on Archimedes spiral drawings (p = 0.019) and were more likely to have head tremor (p = 0.03) than those without it. This sign could be a useful aid in the clinical diagnosis of tremor.

Tremulous cervical dystonia is likely to be familial: Clinical characteristics of a large cohort

BackgroundPrimary cervical dystonia is the most common form of adult-onset focal dystonia. Although most frequently sporadic, 15–20% of patients report a positive family history, suggesting a possible genetic cause. Head tremor is often present in patients with cervical dystonia and may be a prominent symptom. ObjectiveTo describe the clinical characteristics of patients with tremulous cervical dystonia. MethodsPatients with primary cervical dystonia attending our botulinum toxin clinic were assessed with an interview and neurological examination and their notes reviewed. Patients were classified as having either tremulous or non-tremulous cervical dystonia, according to the presence or absence of head tremor on examination. Clinical and demographic data were compared between groups. ResultsFrom 273 patients included (190 females, 83 males), 125 (46%) were classified as tremulous and 148 (54%) as non-tremulous. Tremulous patients were more likely to have a segmental distribution (61% vs 25%), often involving the arms (48%), and had more frequently associated arm tremor (55% vs 10%). A positive family history of dystonia and/or tremor was more frequent in tremulous patients (50% vs 18%). ConclusionsPatients with cervical dystonia with associated head tremor are more likely to have a segmental distribution (with frequent arm involvement), associated arm tremor and a positive family history, suggesting a genetic etiology in this subgroup of patients.