Clinical characteristics of patients with migraine accompanied by tremor

OBJECTIVES

Migraine and tremor share some genetic mutation sites, and clinical studies have also confirmed their correlation. This study aims to explore the clinical and electrophysiological characteristics of migraine patients with concomitant tremor, and to analyze the relevant influential factors of tremor occurrence.

METHODS

We retrospectively analyzed the clinical data of 217 migraine patients who visited the Third Affiliated Hospital of Qiqihar Medical University from June 2022 to October 2023. The Clinical Rating Scale for Tremor (CRST), Numerical Rating Scale (NRS), Generalized Anxiety Disorder-7 (GAD-7), and Patient Health Questionnaire-9 (PHQ-9) were respectively used to assess the tremor symptoms, degree of headache, anxiety, and depression of patients. All patients underwent routine head MR scanning and electromyography examination, and were divided into a migraine with tremor group and a migraine without tremor group based on the electromyogram examination.

RESULTS

The migraine with tremor group and the migraine without tremor group were included 52 patients (23.96%) and 165 patients (76.04%), respectively. Compared with the migraine without tremor group, the migraine with tremor group had a longer course and duration of headache, higher frequency of headache attacks, higher NRS score, GAD-7 score, and PHQ-9 score, and fewer weekly physical exercises. The differences were statistically significant (all P<0.05). There were no statistically significant differences in the presence or absence of prodromal headache and white matter hyperintensities (WMHs) between the 2 groups (both P>0.05). The evaluation results of the CRST showed that out of 217 migraine patients, 39 patients (17.97%) were accompanied by tremors. The electromyographic results showed that all 52 migraine patients with tremors had upper limb tremors, including 28 migraine patients with postural tremors and 24 migraine patients with static tremors. Compared with the migraine patients with static tremors, the migraine patients with postural tremors had lower average frequency, peak frequency, and headache onset frequency (all P<0.05). Multiple linear regression analysis showed that frequency of physical exercise, duration of illness, frequency of headache attacks, NRS score, GAD-7 score, and PHQ-9 score were risk factors for migraine patients with concomitant tremors (all P<0.05).

CONCLUSIONS

Patients with migraine mainly experience upper limb postural tremors. Reduced physical exercise, long course of disease, long duration of headache, frequent headache attacks, severe headache, anxiety, and depression are risk factors for migraine patients with concomitant tremors.

The association between tacrolimus exposure and tremor, headache and insomnia in adult kidney transplant recipients: A systematic review

PURPOSE

Tremor, headache and insomnia have been linked to the immunosuppressant, tacrolimus. The aim of this systematic review was to determine if there is a correlation between tacrolimus exposure and new-onset tremor, headache and insomnia experienced by adult kidney transplant recipients.

METHODS

PubMed, Embase, Cochrane Library and CINAHL databases were searched up to 11 April 2023 for published studies which reported on tacrolimus exposure in adult kidney transplant recipients, alongside information on treatment-emergent neurologic manifestations, including tremor, headache and insomnia. Review articles, case studies, conference abstracts and articles not published in English in peer-reviewed journals were excluded. The Physiotherapy Evidence Database and Newcastle-Ottawa Quality Assessment Scales were used to assess risk of bias. Extracted data was analysed via a narrative synthesis.

RESULTS

Eighteen studies involving 4030 patients in total were included in the final analysis. These comprised five randomised control trials and thirteen observational studies. Studies failed to find significant association between tacrolimus trough concentrations in whole blood and the incidence of neurologic side effects such as tremor, headache and insomnia; however, in one study the incidence of toxicity requiring a dose reduction increased with increasing, supratherapeutic targeted levels. Females, especially Black females, and older age were positively associated with the prevalence of neurologic adverse effects. Results were conflicting regarding whether extended-release formulations were associated with fewer neurologic complications than immediate-release formulations.

CONCLUSION

The varied study designs and criteria for reporting tremor, headache and insomnia impacted on the quality of the data for exploring the relationship between tacrolimus exposure and the onset of neurologic manifestations experienced after kidney transplantation. Studies that examine defined neurologic complications as the primary outcome, and that consider novel markers of tacrolimus exposure while assessing the potential contribution of multiple covariate factors, are required.

The Spectrum of Non-Parkinsonian Tremor: A Registry at a Tertiary Care Teaching Institute

Background

Tremors other than those associated with Parkinson's disease (non-parkinsonian tremor) are commonly observed in clinical settings. However, their frequency and clinical characteristics have rarely been reported.

Objectives

To classify non-parkinsonian tremors based on the consensus statement on the classification of tremors, from the task force of the International Parkinson and Movement Disorder Society published in 2018.

Methods

A prospective registry at a tertiary care teaching institute.

Results

A total of 475 patients with non-parkinsonian tremors were recruited for the study. 67.57% (n = 321) of our patients were male and a family history of tremor was present in 20.84% (n = 99) of patients. Dystonic tremor (DT) was the most common non-parkinsonian tremor (33.26%). 27.78% of patients fulfilled the new classification criteria for essential tremor, with 13.47% classified as pure ET (ET) and 14.31% exhibiting neurological soft signs, leading to the classification of ET plus (ETP). Patients with ETP had more family history (57.35%) [vs DT (26.48%, p = 0.00004) and ET (10.93%, p = 0.00003], longer duration of disease [mean ± standard deviation (SD) = 9.53 ± 8.64 years] [vs DT (5.60 ± 5.93, p = 0.0003) and ET (6.38 ± 5.97, p = 0.01) years], and more severe tremor as measured by the essential tremor rating assessment scale total score [mean ± SD = 27.42 ± 11.70] [vs DT (23.50 ± 8.62, p = 0.007) and ET (22.12 ± 8.19, p = 0.007)] compared with patients with DT and ET.

Conclusions

DT was the most common cause of non-parkinsonian tremor in our registry followed by essential tremor syndrome. ETP was more common than ET.

Dystonic head tremor in paroxysmal dyskinesia in 17 dogs (2021-2023)

BACKGROUND

Dystonia is a common component of the movement disorder paroxysmal dyskinesia (PD) in dogs. However, the incidence of dystonic head tremor (DHT) in these dogs has not previously been evaluated.

METHODS

The medical records of dogs presenting with PD between 2021 and 2023 were retrospectively reviewed, and those with available video footage and the presence of a head tremor were selected for further analysis.

RESULTS

Seventeen of the 39 (43.6%) dogs diagnosed with PD that had video footage available manifested DHT. Poodle or Poodle-cross was the most commonly affected breed (7/17). DHTs were described as fine irregular head tremors accompanied by cervical dystonia (17/17), truncal (11/17) or head (10/17) sway, shifting limb (10/17) or single limb (6/17) dystonia, freezing (8/17), ataxia (6/17), ptyalism (5/17), falling (5/17), kyphosis (4/17) and prayer posture (4/17). Neurological examination and advanced imaging, when available, were within normal limits.

LIMITATIONS

The limitations of the study include its retrospective nature, the lack of video recordings for all PD patients and the lack of electrophysiological evaluation of tremors and electroencephalography.

CONCLUSIONS

DHT exists in dogs with PD; it has characteristic features, and it should be considered in differential diagnoses for dogs with head tremors.

Tremor Induced by Cyclosporine, Tacrolimus, Sirolimus, or Everolimus: A Review of the Literature

Calcineurin inhibitors such as cyclosporine and tacrolimus are immunosuppressant drugs that are known to induce tremors. Non-calcineurin inhibitors such as sirolimus and everolimus have also reportedly been accompanied by tremors, albeit less likely. However, the prevalence rates reported in the literature are notably wide, and the risk profiles for these drug-induced tremors are less understood. We searched PubMed to extract data on the risk of tremors with these drugs when prescribed for various transplant and non-transplant indications. We ascertained whether the risk of drug-induced tremor is influenced by the underlying diagnosis, dosing formulations, drug concentrations, and blood monitoring. We extracted data on treatment strategies and outcomes for tremors. Articles were primarily screened based on English language publications, abstracts, and studies with n ≥ 5, which included case series, retrospective studies, case-controlled studies, and prospective studies. We found 81 eligible studies comprising 33 cyclosporine, 43 tacrolimus, 6 sirolimus, and 1 everolimus that discussed tremor as an adverse event. In the pooled analysis of studies with n > 100, the incidence of tremor was 17% with cyclosporine, 21.5% with tacrolimus, and 7.8% with sirolimus and everolimus together. Regarding the underlying diagnosis, tremor was more frequently reported in kidney transplant (cyclosporine 28%, tacrolimus 30.1%) and bone marrow transplant (cyclosporine 40%, tacrolimus 41.9%) patients compared with liver transplant (cyclosporine 9%, tacrolimus 11.5%) and nontransplant indications (cyclosporine 21.5%, tacrolimus 11.3%). Most studies did not report whether the risk of tremors correlated with drug concentrations in the blood. The prevalence of tremors when using the twice-daily formulation of tacrolimus was nearly the same as the once-daily formulation (17% vs 18%). Data on individual-level risk factors for tremors were lacking. Except for three studies that found some benefit to maintaining magnesium levels, there were minimal data on treatments and outcomes. A large body of data supports a substantive and wide prevalence of tremor resulting from tacrolimus use followed by cyclosporine, especially in patients receiving a kidney transplant. However, there is little reporting on the patient-related risk factors for tremor, risk relationship with drug concentrations, treatment strategies, and outcomes.

Prevalence and Clinical Types of Tremor in Multiple Sclerosis and its Associated Disability: A Systematic Review

Objective

To describe the state of literature regarding prevalence, clinical types of tremor in Multiple Sclerosis and associated disability.

Background

Tremor has long been recognized as an important symptom of multiple sclerosis. This can be intention and postural tremor that affects the upper limbs. Patients with multiple sclerosis who experience tremor of any severity typically retire early or lose their jobs due to disability.

Methods

This systematic review was performed up to September 9, 2022. Article selection was performed by searching the MEDLINE (PubMed) and EMBASE electronic bibliographic databases. The search strategy was not limited by study design but only for articles in the English language.

Results

A total of nine full-text articles were included in the analysis. Six studies were cross-sectional studies; one each was a prospective observational study, a case-control study, a community-based cohort. The prevalence of tremor in the multiple sclerosis (MS) population among studies ranged widely, between 12.5% and 68.9%. The presence of severe tremor ranged from 3% to 33%. Younger age was a significant predictor of tremor in two studies. The most common tremor subtype was action tremor. Upper extremities were the most common site involved in the majority of our studies, followed by head and neck.

Conclusions

Prevalence of tremor ranged from 12.5% to 68.9% in the MS population with severe tremor being an infrequent complication. Severity of tremor correlated with increasing disability. Upper limb action tremor was the most common with rare occurrences of resting and rubral tremor.

Diagnosis of vascular parkinsonism: A new tool for gait hypokinesia occurring in older persons

INTRODUCTION

Reliable diagnosis of vascular parkinsonism (VaP) in the presence of a gait hypokinesia is an issue that is encountered in geriatrics. The EVAMAR-AGEX study was focusing on the phenomenon of recurrent falls in older persons (OP) with this parkinsonian gait. The present study is focusing on the diagnosis of VaP-related parkinsonian gait by developing a diagnostic guidance model adapted to OP.

METHODS

Data from baseline and the 2-year follow-up visit were used to carry out univariate analysis and calculation of odds ratios, allowing to identify relevant variables to include in the diagnostic guidance model. To evaluate the model, confusion matrices were created, evaluating true positive, false negative, false positive and true negative incidences, sensitivity and specificity, and negative and positive predictive values.

RESULTS

79 patients included 58% male; average age 81.24 years. VaP diagnosis according to Zijlmans criteria occurred in 28%; neurodegenerative parkinsonian syndromes in 72%. A 4-criteria model was established to facilitate diagnostic: lack of prior hallucinations, lack of movement disorders tremor excluded, no cognitive fluctuations, and ≥75 years of age at diagnosis. In combination of 4/4 criteria, all of them were required to disclose a specificity of 91% in the diagnosis of VaP. In combination of 3/4, in case of negative test, a negative predictive value for VaP diagnosis of 0.97 was obtained.

CONCLUSION

The challenge of our tool is both to be able to rule out what is probably not a VaP and to argue what makes a VaP diagnosis probable in OP.

Clinical and demographic characteristics of patients with functional movement disorders: a consecutive cohort study from a specialized clinic

There is a growing interest in functional movement disorders (FMD). However, epidemiological data from large cohorts of patients with FMD are scarce and come mainly from General Neurology and Movement Disorders Clinics. Recently, specialized FMD clinics have been developed and epidemiological data from such clinics may provide useful information. We aimed to describe the clinical and sociodemographic features of patients diagnosed with FMD at our specialized FMD clinic. A standardized form was used to extract data from electronic records from the first-100 consecutive patients who were evaluated and diagnosed with FMD at our clinic from 2017 to 2019. Mean age was 40.88 ± (14.02) years, 63% females. Most patients were within working-age range, but only 16% were working at the time of consultation. Mean disease duration was 3.74 ± 5.73 years and was longer among men. The most common FMD were gait disturbance (42%), tremor (22%) and dystonia (15%). A precipitating event (mainly physical) was reported by 74%. The onset was mostly acute (83%) and the clinical course fluctuating (62%). Pain (64%) and fatigue (44%) were common comorbidities. Potential joint-hypermobility was present in 21%, mostly women (90%) and related to the presence of dystonia. FMD affects men and women mostly in working-age. Gait disturbance was the most common diagnosis, possibly because it causes a higher level of disability that may lead to consultation in a specialized clinic. Non-motor symptoms (pain and fatigue) were frequent in this cohort. Further data from specialized units may contribute to both understanding and management of FMD.

Gender differences in motor and non-motor symptoms in early Parkinson disease

Gender differences in motor and non-motor symptoms in Parkinson disease (PD) are still controversial. This study aimed to investigate gender differences in clinical characteristics in patients with early PD.This study included 415 PD patients (201 men and 214 women) with modified Hoehn-Yahr stage 1 to 3 and a disease duration of ≤5 years. Demographic information was obtained by interviews, and motor and non-motor PD symptoms were evaluated with appropriate scales.Women with PD had a shorter duration of formal education than men with PD. No significant differences were found in other demographic variables. Women with PD had significantly lower scores in Unified Parkinson Disease Rating Scale part III and postural tremor compared to men with PD, which was significant after controlling for formal education. No significant gender-related differences were found in scores related to other motor symptoms. Concerning non-motor symptoms, men with PD had higher scores of sexual function on the Non-Motor Symptoms Scale, which means sexual dysfunction was more severe or occurred more frequently in men with PD. Women with PD had significantly higher scores of sleep disturbance in the Pittsburgh Sleep Quality Index, which was not significant after adjustment for multiple comparison.The present study suggests that women with PD had milder motor symptoms compared to men with PD, and gender differences in sexual function can be observed as non-motor symptoms.

Tremor and Rigidity in Patients with Parkinson's Disease: Emphasis on Epidemiology, Pathophysiology and Contributing Factors

Parkinson's disease (PD) is the second most prominent neurodegenerative movement disorder after Alzheimer's disease, involving 2-3% of the population aged above 65 years. This is mainly triggered by the depletion of dopaminergic neurons located in substantia nigra pars compacta (SNpc) in the region of basal ganglia. At present, diagnosis for symptoms of PD is clinical, contextual, unspecified and therapeutically incomprehensive. Analysis of various causes of PD is essential for an accurate examination of the disease. Among the different causes, such as tremors and rigidity, unresponsiveness to the current treatment approach contributes to mortality. In the present review article, we describe various key factors of pathogenesis and physiology associated with tremors and rigidity necessary for the treatment of PI (postural instability) in patients with PD. Additionally, several reports showing early tremor and rigidity causes, particularly age, cortex lesions, basal ganglia lesions, genetic abnormalities, weakened reflexes, nutrition, fear of fall, and altered biomechanics, have been explored. By summarizing the factors that contribute to the disease, histopathological studies can assess rigidity and tremor in PD. With a clear understanding of the contributing factors, various prospective studies can be done to assess the incidence of rigidity and tremors.

Predictive modeling of spread in adult-onset isolated dystonia: Key properties and effect of tremor inclusion

BACKGROUND AND PURPOSE

Several clinical and demographic factors relate to anatomic spread of adult-onset isolated dystonia, but a predictive model is still lacking. The aims of this study were: (i) to develop and validate a predictive model of anatomic spread of adult-onset isolated dystonia; and (ii) to evaluate whether presence of tremor associated with dystonia influences model predictions of spread.

METHODS

Adult-onset isolated dystonia participants with focal onset from the Dystonia Coalition Natural History Project database were included. We developed two prediction models, one with dystonia as sole disease manifestation ("dystonia-only") and one accepting dystonia OR tremor in any body part as disease manifestations ("dystonia OR tremor"). Demographic and clinical predictors were selected based on previous evidence, clinical plausibility of association with spread, or both. We used logistic regressions and evaluated model discrimination and calibration. Internal validation was carried out based on bootstrapping.

RESULTS

Both predictive models showed an area under the curve of 0.65 (95% confidence intervals 0.62-0.70 and 0.62-0.69, respectively) and good calibration after internal validation. In both models, onset of dystonia in body regions other than the neck, older age, depression and history of neck trauma were predictors of spread.

CONCLUSIONS

This predictive modeling of spread in adult-onset isolated dystonia based on accessible predictors (demographic and clinical) can be easily implemented to inform individuals' risk of spread. Because tremor did not influence prediction of spread, our results support the argument that tremor is a part of the dystonia syndrome, and not an independent or coincidental disorder.

Head tremor and pain in cervical dystonia

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.

Ataxia Prevalence in Primary Orthostatic Tremor

Background

The exact pathophysiology of primary Orthostatic Tremor (OT) is unknown. A central oscillator is assumed, and previous imaging studies show involvement of cerebellar pathways. However, the presence of ataxia on clinical exam is disputed. We set out to study ataxia in OT prospectively.

Methods

EMG-confirmed primary OT subjects and spousal controls received a neurological exam with additional semiquantitative evaluations of ataxia as part of a multinational, prospective study. These included detailed limb coordination (DLC), detailed stance and gait evaluation (DS), and the Brief Ataxia Rating Scale (BARS). Intra- and inter-rater reliability were assessed and satisfactory.

Results

34 OT subjects (mean age = 67 years, 88% female) and 21 controls (mean age = 66 years, 65% male) were enrolled. Average disease duration was 18 years (range 4-44). BARS items were abnormal in 88% of OT patients. The OT subjects were more likely to have appendicular and truncal ataxia with significant differences in DLC, DS and BARS. Ocular ataxia and dysarthria were not statistically different between the groups.

Discussion

Mild-to-moderate ataxia could be more common in OT than previously thought. This is supportive of cerebellar involvement in the pathophysiology of OT. We discuss possible implications for clinical care and future research.

Highlights

Previous studies of Primary Orthostatic Tremor (OT) have proposed pathophysiologic involvement of the cerebellar pathways.However, presence of ataxia has not been systematically studied in OT.This is a prospective comprehensive ataxia assessment in OT compared to controls. Mild-to-moderate appendiculo-truncal ataxia was found to be common in OT.

Isolated Voice Tremor: A Clinical Variant of Essential Tremor or a Distinct Clinical Phenotype?

Background

The consensus statement by the Task Force on Tremor of the International Parkinson and Movement Disorder Society excludes individuals with "isolated voice tremor" as a clinical variant of essential tremor (ET). This clinical viewpoint presents a rationale for reconsideration of "isolated voice tremor" as a clinical variant of ET.

Methods

Evidence from the literature was extracted to characterize the clinical phenotype of "isolated voice tremor," or essential vocal tremor (EVT). Clinical features were extracted from relevant literature available at pubmed.gov using the terms "EVT," "essential voice tremor," "primary voice tremor," and "organic voice tremor."

Results

The average age of onset in those with EVT was older than 60 years (range 19-84 years), with 75-93% being female. The typical duration of vocal tremor ranged from 1 to 13 years (average 6 years). The distribution of structures exhibiting tremor included the larynx, soft palate, pharynx, and base of tongue in the majority of patients, with some exhibiting tremor of the head and respiratory musculature. The condition of tremor occurred during speech and quiet respiration in 74% of individuals. Rate of tremor ranged from 4 to 10 Hz. Nearly 70% reported onset of vocal tremor prior to upper limb involvement. Family history of tremor was reported in 38-42% of individuals.

Discussion

Those previously classified with EVT demonstrate a similar familial history, rate, tremor classification, and body distribution of ET. EVT is proposed as a clinical variant of ET in the pattern of onset and progression of body distribution from the midline cranial to spinal neural pathways.

Survival and Progression in Synucleinopathy Phenotypes With Parkinsonism: A Population-Based Study

OBJECTIVE

To compare survival by the presenting parkinsonism symptoms at diagnosis among patients with incident clinically diagnosed synucleinopathies.

PATIENTS AND METHODS

Using the Rochester Epidemiology Project medical records-linkage system, we identified all persons residing in Olmsted County, Minnesota, who received a diagnostic code of parkinsonism from January 1, 1991, through December 31, 2010. A movement disorder specialist reviewed the complete medical records of each individual to confirm the presence of parkinsonism, determine the type of synucleinopathy, and identify the onset dates of each cardinal symptom (tremor at rest, bradykinesia, rigidity, and impaired postural reflexes). We determined the median time from age at diagnosis to death or censoring (June 30, 2015) for each presenting symptom and the age- and sex-adjusted risk of death.

RESULTS

From 1991 through 2010, a total of 433 individuals had a synucleinopathy diagnosed (301 [69.5%], Parkinson disease; 68 [15.7%], dementia with Lewy bodies; 52 [12.0%], Parkinson disease dementia; and 12 [2.8%], multiple systems atrophy with parkinsonism). Overall, the risk of death in the tremor-predominant group was less than that in the bradykinesia/rigidity-only group (hazard ratio [HR], 0.59; 95% CI, 0.40-0.87; P=.007). Similarly, risk of death in the bradykinesia/rigidity-only group was significantly greater than in the tremor-predominant group (HR, 1.75; 95% CI, 1.23-2.51; P=.002) and compared with tremor before bradykinesia (HR, 1.75; 95% CI, 1.24-2.47; P=.001).

CONCLUSION

Patients with tremor as a presenting symptom have longer survival. In contrast, the presence of bradykinesia/rigidity as a presenting symptom correlates with reduced survival across all types of synucleinopathies.

The use of smartphone in measuring stance and gait patterns in patients with orthostatic tremor

Orthostatic tremor (OT) is a rare movement disorder characterized by a fast tremor (13–18 Hz) in the lower extremities during stance. Patients with OT typically complain of instability while standing/walking. However, due to the geographical limitation, the standing instability or gait problems in patients with OT cannot be assessed and monitored frequently. The increasing popularity of using smartphone-based accelerometers could be a solution to eliminate this limitation. This study examined the feasibility of using smartphone-based accelerometers to identify the changes in body movement in different standing and locomotor tasks. Twenty patients with OT and seven healthy controls were consented to participate in this study. Subjects stood with eyes open or eyes closed for 20 seconds. They also performed four different locomotor tasks (normal walking, tandem walk, walking on an elevated surface, and obstacle negotiation). When performed different locomotor tasks, patients with OT had a larger acceleration of body movement than controls in the medial-lateral direction (tandem walk: p = 0.026, walking on an elevated surface: p = 0.002, and stepping over the obstacle: p = 0.028). Patients with OT had smaller acceleration of body movement than controls while standing with eyes open in the vertical direction (p = 0.012), in the anterior-posterior direction (p = 0.013) and in the medial-lateral direction (p = 0.011). This study provides objective evidence of balance instability in patients with OT not only while standing but also during different challenging locomotor tasks by using smartphone-based accelerometers.

Head tremor at disease onset: an ataxic phenotype of cervical dystonia

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.

Tremor in normal adults: A population-based study of 1158 adults in the Faroe Islands

There are virtually no population-based data on tremor in normal individuals. Using a population-based sample of 1158 normal adults ages 40-98 years in the Faroe Islands, we characterized the extent of normal action tremor across age and gender strata. Participants drew two Archimedes spirals with each hand, and tremor was systematically quantified by a senior movement disorder neurologist using a reliable and valid ordinal rating scale (ratings = 0-3). Tremor was nearly universal - 1145 (98.9%) participants had a total mean spiral score > 0. Older age was associated with more tremor (p < .001) and spiral scores were higher in males than females (p < .001). The proportion of individuals with a spiral rating ≥ 1.5 (i.e., more than mild tremor) was low (1.8% - 8.5%); however, this value reached 19.6% in left-hand spirals of males ≥70 years old. In this population-based study of more than one thousand normal adults, the vast bulk (i.e., 98.9%) had tremor on spiral drawing. In general, the tremor was mild. The proportion of individuals with tremor above the mild range varied across age and gender strata. These extensive data may be used as a gold standard for defining normal levels of tremor within adult populations.

The nature of postural tremor in Parkinson disease

OBJECTIVE

To disentangle the different forms of postural tremors in Parkinson disease (PD).

METHODS

In this combined observational and intervention study, we measured resting and postural tremor characteristics in 73 patients with tremulous PD by using EMG of forearm muscles. Patients were measured both "off" medication (overnight withdrawal) and after dispersible levodopa-benserazide 200/50 mg. We performed an automated 2-step cluster analysis on 3 postural tremor characteristics: the frequency difference with resting tremor, the degree of tremor suppression after posturing, and the dopamine response.

RESULTS

The cluster analysis revealed 2 distinct postural tremor phenotypes: 81% had re-emergent tremor (amplitude suppression, frequency difference with resting tremor 0.4 Hz, clear dopamine response) and 19% had pure postural tremor (no amplitude suppression, frequency difference with resting tremor 3.5 Hz, no dopamine response). This finding was manually validated (accuracy of 93%). Pure postural tremor was not associated with clinical signs of essential tremor or dystonia, and it was not influenced by weighing.

CONCLUSION

There are 2 distinct postural tremor phenotypes in PD, which have a different pathophysiology and require different treatment. Re-emergent tremor is a continuation of resting tremor during stable posturing, and it has a dopaminergic basis. Pure postural tremor is a less common type of tremor that is inherent to PD, but has a largely nondopaminergic basis.

Fragile X-associated tremor/ataxia syndrome

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a hereditary neurodegenerative disorder caused by a mutation on the X chromosome. The major signs and symptoms are tremor, ataxia and parkinsonism. Up to one in 2 000 persons over 50 years of age will develop the syndrome. There is reason to believe that too few individuals in Norway undergo testing for this condition.

The clinical features and functional impact of valproate-induced tremor

BACKGROUND

Tremor is a known side-effect of anticonvulsants, particularly of valproate. However, there is a dearth of information regarding detailed clinical features and functional impact of valproate-induced tremor.

METHODS

We studied a cohort of patients treated with anticonvulsants for neurological disorders, through blinded evaluations using the Clinical Rating Scale for Tremor (CRST); we compared the frequency, severity and functional impact of drug-induced tremor between patients treated with valproate and those treated with other anticonvulsants.

RESULTS

From a cohort of 218 consecutive patients, 171 were fully evaluated; 118 patients were taking valproate alone or combined with other anticonvulsants and 53 patients were taking other anticonvulsants. Mean age (±SD) at evaluation of the cohort was 32 ± 13 years, females represented 55.6% of cases. Tremor was more frequently observed in patients taking valproate particularly postural upper limb tremor: 49% vs. 15% (right-side) (P < 0.001) and 48.3% vs. 13.2% (left-side), (P < 0.001); had a higher total CRST score: 12.14 vs. 3.06 (P < 0.001), and required more frequently treatment for drug-induced tremor: 23.7% vs. 5.6% (P=0.005) compared with patients taking other anticonvulsants. Among 118 patients taking valproate, women had a higher total CRST score compared with men: 14.54 ± 14.9 vs. 9.56 ± 9.55 (P=0.034). A weak correlation between the total CRST score, dose per Kg of valproate and serum levels of valproate were observed.

CONCLUSIONS

Tremor is frequently observed in patients taking valproate and is severe enough to require treatment in about 24% of cases.

Is tremor related to celiac disease?

Neurological features in celiac disease (CD) are not rare (5%-36%), but tremor is scarcely described. Subjects with CD and healthy controls completed an online survey using WHIGET tremor rating scale. One thousand five hundred and twelve subjects completed the survey, finally 674 CD patients and 290 healthy subjects were included. A higher prevalence of tremor in CD patients was observed in comparison to controls (28% vs 14%, P < 0.001). Frequency of family history of tremor in CD patients with and without tremor was 25% and 20% (P = 0.2), while in the control group it was 41% and 10% (P < 0.001). Controls with tremor showed a higher frequency of family history of tremor when compared to CD patients with tremor (41.5% vs 24.6%, P = 0.03). The results suggested that tremor in CD might be more frequent and possibly related to the disease itself and not due to associated essential tremor.

Aging in Fragile X Premutation Carriers

It is now recognized that FMR1 premutation carriers (PC) are at risk to develop a range of neurological, psychiatric, and immune-mediated disorders during adulthood. There are conflicting findings regarding the incidence of hypertension, hypothyroidism, diabetes, and cancer in these patients that warrant further study. A retrospective controlled study was performed in a convenience sample of 248 controls (130 men, 118 women) and 397 FMR1 PC with and without fragile X-associated tremor ataxia syndrome (FXTAS) (176 men, 221 women); all participants were at least 45 years old (men: mean 62.4, SD 9.5; women: mean 62.8, SD 9.9; p = 0.63). Memory and cognitive assessments (Wechsler Adult Intelligence Scale (WAIS-III), Wechsler Memory Scale (WMS-III)) and molecular testing (CGG repeats and FMR1-mRNA levels) were performed. Additional data included body mass index (BMI), cholesterol levels, blood pressure, hemoglobin A1c (HbA1c) levels, and medical history. A higher percentage of PC subjects self-reported having a diagnosis of hypertension (50.0 vs. 35.0 %, p = 0.006) and thyroid problems (20.4 vs. 10.0 %, p = 0.012) than control subjects. When comparing controls versus PC with FXTAS, the association was higher for diabetes (p = 0.043); however, the effect was not significant after adjusting for demographic predictors. Blood pressure, blood glucose levels, HbA1c, and BMI values were not significantly different between the two groups. The PC with FXTAS group performed consistently lower in neuropsychological testing compared with the PC without FXTAS group, but the differences were very small for all but the WAIS full-scale IQ. Based on these findings, it appears that the risk for hypertension, thyroid problems, and diabetes may be more frequent in PC with FXTAS, which will require verification in future studies.

Tremor in progressive supranuclear palsy

INTRODUCTION

Tremor is thought to be a rare feature of progressive supranuclear palsy (PSP).

METHODS

We retrospectively reviewed the database of the CurePSP brain bank at Mayo Clinic Florida to retrieve all available clinical information for PSP patients. All patients underwent a standard neuropathological assessment and an immunohistochemical evaluation for tau and α-synuclein. DNA was genotyped for the MAPT H1/H2 haplotype.

RESULTS

Of the 375 PSP patients identified, 344 had a documented presence or absence of tremor, which included 146 (42%) with tremor, including 29 (20%) with postural/action tremors, 16 (11%) with resting tremor, 7 (5%) with intention tremor, 20 (14%) with a combination of different types of tremor, and 74 (51%) patients who had tremor at some point during their illness, but details were unavailable. The tremor severity of 96% of the patients (54/55) who had this data was minimal to mild. The probability of observing a tremor during a neurological examination during the patient's illness was estimated to be ∼22%. PSP patients with postural/action tremors and PSP patients with resting tremor responded to carbidopa-levodopa therapy more frequently than PSP patients without tremor, although the therapy response was always transient. There were no significant differences in pathological findings between the tremor groups.

CONCLUSIONS

Tremor is an inconspicuous feature of PSP; however, 42% (146/344) of the PSP patients in our study presented some form of tremor. Because there is no curative therapy for PSP, carbidopa/levodopa therapy should be tried for patients with postural, action, and resting tremor.

Psychiatric comorbidities in patients from seven families with autosomal dominant cortical tremor, myoclonus, and epilepsy

OBJECTIVE

The objective of this report was to assess the psychiatric comorbidity in a group of patients affected by autosomal dominant cortical tremor, myoclonus, and epilepsy (ADCME).

METHODS

Reliable and validated psychodiagnostic scales including the BDI (Beck Depression Inventory), STAI-Y1 and 2 (State-Trait Anxiety Inventory - Y; 1 and 2), MMPI-2 (Minnesota Multiphasic Personality Inventory - 2), and QoLIE-31 (Quality of Life in Epilepsy Inventory - 31) were administered to 20 patients with ADCME, 20 patients with juvenile myoclonic epilepsy (JME), and 20 healthy controls.

RESULTS

There was a higher prevalence of mood disorders in patients with ADCME compared to patients with JME and healthy controls, particularly depression (p=0.035 and p=0.017, respectively) and state anxiety (p=0.024 and p=0.019, respectively). Trait anxiety was not different from JME (p=0.102) but higher than healthy controls (p=0.017). The myoclonus score positively correlated with both state (rho: 0.58, p=0.042) and trait anxiety (rho: 0.65, p=0.011). These psychiatric features were also often associated with pathological traits of personality: paranoid (OR: 25.7, p=0.003), psychasthenia (OR: 7.0, p=0.023), schizophrenia (OR: 8.5, p=0.011), and hypomania (OR: 5.5, p=0.022). Finally, in patients with ADCME, decreased quality of life correlated with these psychiatric symptoms.

SIGNIFICANCE

Patients with ADCME show a significant psychiatric burden that impairs their quality of life. A comprehensive psychiatric evaluation should be offered at the time of diagnosis to detect these comorbidities and to treat them.

Environmental exposure to manganese in air: Associations with tremor and motor function

BACKGROUND

Manganese (Mn) inhalation has been associated with neuropsychological and neurological sequelae in exposed workers. Few environmental epidemiologic studies have examined the potentially neurotoxic effects of Mn exposure in ambient air on motor function and hand tremor in adult community residents. Mn exposed residents were recruited in two Ohio towns: Marietta, a town near a ferro-manganese smelter, and East Liverpool, a town adjacent to a facility processing, crushing, screening, and packaging Mn products.

METHODS

Chronic (≥ 10 years) exposure to ambient air Mn in adult residents and effects on neuropsychological and neurological outcomes were investigated. Participants from Marietta (n=100) and East Liverpool (n=86) were combined for analyses. AERMOD dispersion modeling of fixed-site outdoor air monitoring data estimated Mn inhalation over a ten year period. Adult Mn-exposed residents' psychomotor ability was assessed using Finger Tapping, Hand Dynamometer, Grooved Pegboard, and the Computerized Adaptive Testing System (CATSYS) Tremor system. Bayesian structural equation modeling was used to assess associations between air-Mn and motor function and tremor.

RESULTS

Air-Mn exposure was significantly correlated in bivariate analyses with the tremor test (CATSYS) for intensity, center frequency and harmonic index. The Bayesian path analysis model showed associations of air-Mn with the CATSYS non-dominant center frequency and harmonic index; while the Bayesian structural equation model revealed associations between air-Mn and lower Finger Tapping scores. Household income was significantly associated with motor dysfunction but not with tremor.

CONCLUSION

Tremor and motor function were associated with higher exposure to airborne Mn.

Prevalence and characteristics of tremor in the NARCOMS multiple sclerosis registry: a cross-sectional survey

OBJECTIVES

(1)To describe the prevalence and severity of tremor in patients with multiple sclerosis (MS) registered within a large North American MS registry; (2) to provide detailed descriptions on the characteristics and severity of tremor in a subset of registrants and (3) to compare several measures of tremor severity for strength of agreement.

SETTING

The North American Research Committee on MS (NARCOMS) registry.

PARTICIPANTS

Registrants of NARCOMS reporting mild or greater tremor severity.

OUTCOME MEASURES

We determined the cross-sectional prevalence of tremor in the NARCOMS registry over three semiannual updates between fall 2010 and fall 2011. A subset of registrants (n=552) completed a supplemental survey providing detailed descriptions of their tremor. Outcomes included descriptive characteristics of their tremors and correlations between outcome measures to determine the strength of agreement in assessing tremor severity.

RESULTS

The estimated prevalence of tremor in NARCOMS ranged from 45% to 46.8%, with severe tremor affecting 5.5-5.9% of respondents. In the subset completing the supplemental survey, mild tremor severity was associated with younger age of MS diagnosis and tremor onset than those with moderate or severe tremor. However, tremor severity did not differ by duration of disease or tremor. Respondents provided descriptions of tremor symptoms on the Clinical Ataxia Rating Scale, which had a moderate to good (ρ=0.595) correlation with the Tremor Related Activities of Daily Living (TRADL) scale. Objectively scored Archimedes' spirals had a weaker (ρ=0.358) correlation with the TRADL. Rates of unemployment, disability and symptomatic medication use increased with tremor severity, but were high even among those with mild tremor.

CONCLUSIONS

Tremor is common among NARCOMS registrants and severely disabling for some. Both ADL-based and symptom-descriptive measures of tremor severity can be used to stratify patients.

Motor systems and postural instability

Acute alcohol intoxication and chronic alcohol dependence alter the neurologic control of posture and motor function. Ethanol delays the conduction of electric signals from the central nervous system to the muscles controlling posture and impairs the integration of sensory inputs required for maintaining vertical stance. Consequently, alcohol intoxication delays the ability to detect postural changes and enact the appropriate response. Common signs of acute alcohol intoxication include spinocerebellar and vestibulocerebellar ataxia, oculomotor changes, and increased reliance on visuospatial clues. Chronic alcoholism results in postural tremors and excessive sway during quiet stance that can persist even after sobriety is achieved. Underlying neurologic changes due to chronic alcoholism have been found to be associated with these characteristic postural changes and include decreased volume of the anterior superior vermis of the cerebellum, decreased connectivity within the corpus callosum, and overall cortical atrophy. Severity of motor impairments and other symptoms from alcoholism relate to a variety of factors, including duration of alcoholism, age, sex, and other health determinants and comorbidities. Imaging studies highlight the potential for partial recovery from neurologic and motor deficits caused by alcoholism. Emerging evidence on the motor and neurologic changes caused by alcohol dependence may allow for improved treatment and prevention of the morbidities associated with alcoholism.

Is action tremor in Parkinson's disease related to resting tremor?

OBJECTIVE

Action tremor (AT) and resting tremor (RT) have been widely cited in many studies with Parkinson's disease (PD) patients, but studies looking at the association between the two tremor types are few and show inconsistent results. This study will look at the prevalence and association of AT and RT in a large sample of idiopathic PD patients, and will put the results into context with the literature.

METHODS

A retrospective chart review analysis of 332 patients with idiopathic PD was performed. Prevalence rates of particular tremor types were noted. The presence of AT was analyzed relative to the presence and severity of RT.

RESULTS

Nearly all individuals with AT also had RT. The concurrence of the two tremor types was found to be highly significant by statistical analysis (P < 0.0001). The severity of RT, measured by its laterality, may also be of importance, albeit to a much smaller extent if at all. Neither presence of tremor nor type of tremor present was influenced by patient gender, age, or Hoehn and Yahr stage of PD.

CONCLUSIONS

The results indicate that AT has extensive presence in PD. This and its seemingly close relationship to RT suggest that AT may be considered a variant of RT, particularly in PD patients. The degree of association between RT and AT needs to be further analyzed in PD, as well as in essential tremor (ET) and ET-PD.

Cerebellar learning distinguishes inflammatory neuropathy with and without tremor

OBJECTIVES

This study aims to investigate if patients with inflammatory neuropathies and tremor have evidence of dysfunction in the cerebellum and interactions in sensorimotor cortex compared to nontremulous patients and healthy controls.

METHODS

A prospective data collection study investigating patients with inflammatory neuropathy and tremor, patients with inflammatory neuropathy without tremor, and healthy controls on a test of cerebellar associative learning (eyeblink classical conditioning), a test of sensorimotor integration (short afferent inhibition), and a test of associative plasticity (paired associative stimulation). We also recorded tremor in the arms using accelerometry and surface EMG.

RESULTS

We found impaired responses to eyeblink classical conditioning and paired associative stimulation in patients with neuropathy and tremor compared with neuropathy patients without tremor and healthy controls. Short afferent inhibition was normal in all groups.

CONCLUSIONS

Our data strongly suggest impairment of cerebellar function is linked to the production of tremor in patients with inflammatory neuropathy.

[Alzheimer's disease and fragile X syndrome: the Wnt/ß-catenin pathway as a common biological mechanism]

INTRODUCTION

Various disorders affecting the canonical Wnt/ß-catenin signalling pathway have been related to the activation or inactivation of oncogenes and tumour suppressor genes that give rise to a number of well-defined neoplasias, as well as several genes involved in a growing group of complaints, including Alzheimer's disease (AD) and fragile X syndrome (FXS).

AIM

To examine the Wnt/ß-catenin signalling pathway as a possible common biological mechanism involved in the origin and development of neurodegenerative conditions and its relationship with cancer.

DEVELOPMENT

We review the most recent biomedical literature dealing with the Wnt/ß-catenin signalling pathway and its participation in the genesis of complaints such as AD and FXS. An analysis is also conducted to determine the role that this metabolic pathway might play in explaining the lowered risk of developing cancer displayed by these patients.

CONCLUSIONS

The evidence found suggests that the Wnt/ß-catenin pathway could be regulating a set of genes linked with the control of the cell cycle and apoptosis. This would give rise to a metabolic state in which, in conditions such as AD and FXS, the cells would be more likely to undergo apoptosis than initiate mitosis, which would in turn account for the reduced risk of developing cancer.

[Essential tremor and Parkinson's disease: are they associated?]

INTRODUCTION

There is now growing evidence that essential tremor and Parkinson's disease are related.

AIM

To present the main findings from epidemiologic, genetic, clinical, imaging and pathologic studies, contrasting evidences for and against an association between essential tremor and Parkinson's disease.

DEVELOPMENT

We include a complete update of the latest findings regarding the overlap between these two disorders. There is current evidence that a history of essential tremor may herald the onset of Parkinson's disease in a subset of patients. Furthermore, the fact that the risk of essential tremor is significantly increased in relatives of patients with Parkinson's disease suggests the possibility that both conditions are genetically related, probably sharing common hereditary predisposition. Dopaminergic deficit among essential tremor patients in functional imaging studies and recent pathological studies describing Lewy bodies in some essential tremor patients, support further evidence for an overlap between both conditions, at least in a subset of patients.

CONCLUSION

The convergence of all the reviewed data suggests the possible existence of a mixed essential tremor-Parkinson's disease phenotype in some patients. However, further studies are needed to better understand this phenotype.

Prepulse inhibition in patients with fragile X-associated tremor ataxia syndrome

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late onset neurodegenerative disorder that affects carriers of the fragile X premutation, typically after age 50. Common symptoms include intention tremor, ataxia, neuropathy, autonomic dysfunction, cognitive decline, and dementia. The objectives of this study were to determine if patients with FXTAS have altered prepulse inhibition (PPI; a measure of sensorimotor gating), and to study possible correlations between PPI, molecular status, and cognitive performance. A passive acoustic PPI paradigm was applied in 163 subjects; 121 carriers of the fragile X premutation, and 42 healthy controls. There were significant differences in PPI between premutation carriers with FXTAS and controls at PPI 60 ms, and at 120 ms. This effect was more prominent in the male FXTAS patients. There was a tendency to an impaired PPI in female premutation carriers at the 120 ms condition. There was a significant correlation between the PPI deficit and a higher CGG repeat number. The results show an impairment in sensorimotor gating processes in male carriers of the fragile X premutation, which is more prominent in patients with FXTAS.

[Orthostatic tremor: an enigmatic condition]

INTRODUCTION

Orthostatic tremor is a rare kind of tremor which is clinically characterised by a feeling of instability or being about to fall that is experienced on standing up, which disappears or improves on walking and is absent when sitting or lying down.

AIM

To shed light on the main features of this tremor syndrome.

DEVELOPMENT

First, its clinical spectrum is defined, with emphasis on the key characteristics that enable us to make an initial approximation to its syndromes. Then the main neurophysiological features that make up the electromyographic profile of orthostatic tremor are described. Finally, the pathophysiological hypotheses regarding the genesis of this kind of tremor are addressed and the therapeutic options currently available are described.

CONCLUSIONS

The convergence of all the data reviewed provides a complete, critical analysis of this enigmatic motor disorder, thus allowing a rigorous approach to its main characteristics, which makes both its clinical recognition and its therapeutic management easier.

Fragile X-associated tremor/ataxia syndrome

Fragile X-associated tremor/ataxia syndrome (FXTAS) is an under-recognized disorder that is a significant cause of late-adult-onset ataxia. The etiology is expansion of a trinucleotide repeat to the premutation range (55-200 CGG repeats) in the fragile X mental retardation 1 (FMR1) gene. Expansion to >200 CGGs causes fragile X syndrome, the most common heritable cause of cognitive impairment and autism. Core features of FXTAS include progressive action tremor and gait ataxia; with frequent, more variable features of cognitive decline, especially executive dysfunction, parkinsonism, neuropathy, and autonomic dysfunction. MR imaging shows generalized atrophy and frequently abnormal signal in the middle cerebellar peduncles. Autopsy reveals intranuclear inclusions in neurons and astrocytes and dystrophic white matter. FXTAS is likely due to an RNA toxic gain-of-function of the expanded-repeat mRNA. The disorder typically affects male premutation carriers over age 50, and, less often, females. Females also are at increased risk for primary ovarian insufficiency, chronic muscle pain, and thyroid disease. Treatment targets specific symptoms, but progression of disability is relentless. Although the contribution of FXTAS to the morbidity and mortality of the aging population requires further study, the disorder is likely the most common single-gene form of tremor and ataxia in the older adult population.

Tremor and β(2)-adrenergic agents: is it a real clinical problem?

Tremor is one of the most characteristic adverse effects following administration of β(2)-adrenergic agonists. It is reported by around 2-4% of patients with asthma taking a regular β(2)-adrenergic agonist and is induced by both short-acting and long-acting agents. Tremor associated with β(2)-adrenergic agonists is dose-related and may occur more commonly with oral dosing. The exact mechanism for tremor induction by β(2)-adrenergic agonists is still unknown, but there is some evidence that β(2)-adrenergic agonists act directly on muscle. An early explanation of the tremor was that β(2)-adrenoceptor stimulation shortens the active state of skeletal muscle, which leads to incomplete fusion and reduced tension of tetanic contractions. More recently, tremor has been correlated closely with hypokalaemia. A possible diverse impact of different modes of administration of β(2)-adrenergic agonists on tremorogenic responses has been suggested but solid evidence is still lacking. In any case, the desensitization of β(2)-adrenoceptors that occurs during the first few days of regular use of a β(2)-adrenergic agonist accounts for the commonly observed resolution of tremor after the first few doses. Therefore, tremor is not a really important adverse effect in patients under regular treatment with a β(2)-adrenergic agonist.

Quantitative analysis of tremors in welders

Background:

Workers chronically exposed to manganese in welding fumes may develop an extra-pyramidal syndrome with postural and action tremors.

Objectives:

To determine the utility of tremor analysis in distinguishing tremors among workers exposed to welding fumes, patients with Idiopathic Parkinson’s Disease (IPD) and Essential Tremor (ET).

Methods:

Retrospective study of recorded tremor in subjects from academic Movement Disorders Clinics and Welders. Quantitative tremor analysis was performed and associated with clinical status.

Results:

Postural tremor intensity was increased in Welders and ET and was associated with visibly greater amplitude of tremor with arms extended. Mean center frequencies (Cf) of welders and patients with ET were significantly higher than the mean Cf of PD subjects. Although both the welders and the ET group exhibited a higher Cf with arms extended, welders could be distinguished from the ET subjects by a significantly lower Cf of the rest tremor than that measured in ET subjects.

Conclusions:

In the context of an appropriate exposure history and neurological examination, tremor analysis may be useful in the diagnosis of manganese-related extra-pyramidal manifestations.

Neuromotor effects of short-term and long-term exposures to trichloroethylene in workers

BACKGROUND

Health effects of long-term exposure to organic solvents at low levels are a major concern in industrialized countries. To assess the neuromotor impact of trichloroethylene objectively, static postural sway and hand tremor parameters, along with urinary trichloroethanol (TCOH) and trichloroacetic acid (TCAA) levels, were investigated in 57 workers without obvious neurological disorders and 60 control subjects.

METHODS

The workers had been occupationally exposed to trichloroethylene for 0.1-37 years. The cumulative exposure index (CEI) was calculated from their occupational history and total trichloro-compounds (TCOH + TCAA).

RESULTS

Median levels in the workers were 1.7 mg/L for TCOH and 2.5 mg/L for TCAA, and the maximum ambient trichloroethylene concentration was estimated to be <22 ppm from the previously reported equation using TCOH + TCAA. Sway parameters with eyes open and tremor intensity in dominant hand were significantly larger in the exposed workers than in the control subjects when adjusting for possible confounders. A significant dose-effect association was seen between two sway parameters and urinary TCOH level in the workers. Tremor intensities in non-dominant hand differed significantly among three groups of the workers divided according to the CEI.

CONCLUSIONS

These findings suggest that trichloroethylene exposure, even at low levels of less than the short-term exposure limit by the ACGIH, can affect the neuromotor function of workers. The postural instability appears to result from recent exposure, and the increased tremor may occur due to short-term and long-term exposures. Hereafter, such objective measures, along with subjective symptoms, should be carefully used for the occupational exposure limit setting.

Indole-diterpenes and ergot alkaloids in Cynodon dactylon (Bermuda grass) infected with Claviceps cynodontis from an outbreak of tremors in cattle

Tremorgenic syndromes in mammals are commonly associated with indole-diterpenoid alkaloids of fungal origin. Cattle are sometimes affected by tremors (also called "staggers") when they graze on toxic grass pastures, and Bermuda grass ( Cynodon dactylon , kweek) has been known to be associated with tremors for several decades. This study reports the identification of paspalitrems and paspaline-like indole-diterpenes in the seedheads of Claviceps cynodontis -infected Bermuda grass collected from a pasture that had caused a staggers syndrome in cattle in South Africa and thereby links the condition to specific mycotoxins. The highest concentration (about 150 mg/kg) was found for paspalitrem B. Ergonovine and ergine (lysergic acid amide), together with their C-8 epimers, were found to co-occur with the indole-diterpenes at concentrations of about 10 microg/kg. The indole-diterpene profile of the extract from the ergotized Bermuda grass was similar to that of Claviceps paspali sclerotia. However, the C. paspali sclerotia contained in addition agroclavine and elymoclavine. This is the first study linking tremors associated with grazing of Bermuda grass to specific tremorgenic indole-diterpenoid mycotoxins.

[Fragile X-associated tremor/ataxia syndrome]

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a recently characterized adult onset neurodegenerative disorder affecting both male and female (male>female) carriers of premutation CGG repeat expansions of the FMR1 gene. Onset typically occurs after the age of 50 years with a lifetime risk of FXTAS in males of about 1 in 3,000-6,000. Core features include progressive gait ataxia and cerebellar tremor with associated features of cognitive deficits, peripheral neuropathy and dysautonomia. The diagnosis of FXTAS is established based on clinical presentation, cerebral imaging and genetic testing. Due to the still low level of awareness of FXTAS and its variable clinical picture FXTAS is substantially underdiagnosed. However, confirming the diagnosis is essential for genetic counseling of the patients as the offspring are at risk for fragile X syndrome, premature ovarian insufficiency (POI) or FXTAS. Furthermore, many features of FXTAS can be treated symptomatically.

Neurologic complications after renal transplant

OBJECTIVES

Neurologic complications are a significant cause of morbidity and mortality in patients who undergo transplants. We sought to evaluate the nature and incidence of neurologic complications in patients undergoing a renal transplant.

PATIENTS AND METHODS

Between January 2005 and December 2007, 132 adults (35 women, 97 men; mean age, 34.32 -/+ 0.90 years) underwent a renal transplant at our institution. Associated comorbid medical conditions, presenting neurologic symptoms, and type of immunosuppression were obtained from patients' medical records.

RESULTS

Major indications for renal transplant were hypertensive nephropathy (14.4%), vesicoureteral reflux (11.4%), and idiopathic causes (21.2%). Mean follow-up was 17.26 -/+ 0.89 months (range, 2 weeks to 40 months). Twenty neurologic complications were found in 18 patients (6 women, 12 men; mean age, 33.83 -/+ 2.37 years). Presenting symptoms included posterior leukoencephalopathy syndrome, 1 (5.6%); cephalgia, 10 (55.6%); cerebral infarcts, 2 (11.1%); seizure, 3 (16.7%); tremor, 2 (11.1%); encephalopathy, 1 (5.6%); and sinus thrombosis, 1 (5.6%). Immunosuppressive agents were the primary cause of 16 of the 20 neurologic complications. Effectiveness and complications of cyclosporinewere screened for a total of 1858.50 months, tacrolimus for 853.50 months, and sirolimus for 620 months; 50.2% of the neurologic complications appeared during the first 3 months after transplant; the blood level of immunosuppressive medications did not need to be higher than normal in every case.

DISCUSSION

In addition to cyclosporine and tacrolimus, we suggest (for the first time) sirolimus as a cause of neurocomplications after renal transplant.

Evaluation of the Unified Wilson's Disease Rating Scale (UWDRS) in German patients with treated Wilson's disease

Wilson's disease (WD) is an inherited autosomal-recessive disorder of copper metabolism characterized by a wide variety of neurological, hepatic, and psychiatric symptoms. The aim of the present study was the development and evaluation of a clinical rating scale, termed Unified Wilson's Disease Rating Scale (UWDRS), to assess the whole spectrum of clinical symptoms in WD. Altogether 107 patients (mean age 37.6 +/- 11.9 years; 46 male, 61 female) with treated WD participated in the study. Cronbach's alpha as a measure of the internal consistency for the entire scale was 0.92, whereas the intraclass correlation coefficient (ICC) was 0.98 (confidence interval (CI(95%)) 0.97-0.99), indicating an excellent interrater reliability as determined in 32 patients. Besides the total score was significantly correlated with the earning capacity of the patients as indicated by an estimated Spearman's rho approximately 0.54 (CI(95%) 0.40-0.69, P < 0.001). In summary, the UWDRS appears to be a promising tool to assess the disease severity in WD. Its usefulness in clinical research and drug trials should be further addressed.

Tremor frequency profile as a function of level of mental retardation

The characteristic slowness of movement initiation and execution in adult individuals with mental retardation may be driven by the slower frequency profile of the dynamics of the system. To investigate this hypothesis, we examined the resting and postural finger tremor frequency profile (single and dual limb) of adults as a function of level of mental retardation (moderate, severe, profound). There was a progressive increase in the contribution of slow frequency components to the enhanced amplitude of tremor as a function of mental retardation, particularly in the group with profound mental retardation. Findings support the hypothesis of mental retardation inducing a slower frequency to the system dynamics that may fundamentally drive the characteristic slowness of movement behavior.

New onset heightened interest or drive for gambling, shopping, eating or sexual activity in patients with Parkinson's disease: the role of dopamine agonist treatment and age at motor symptoms onset

Alterations of impulse control that have recently been associated with Parkinson's disease (PD) are serious behavioural disturbances with significant impact on PD patients and their families.A total of 193 consecutive PD patients with no history of psychiatric illness and 190 age/gender-matched healthy controls were queried on the presence of new onset heightened interest or drive for gambling, shopping, eating or sexual activity (GSES). Clinical data were retrieved from medical charts and interviews. logistic regressions models assessed risk factors for these specific troublesome behaviours. New or heightened interests or drives for GSES behaviours were reported by 27 patients (14% vs 0% for controls). Younger age at PD motor symptoms onset (OR = 0.99, p = 0.0172), male gender (OR = 1.10, p = 0.0576) and longer duration of treatment with dopamine agonists (DAs)(OR = 1.18, >/=6 years versus never treated, p = 0.0459) contributed additively to the risk of developing one or more of these behavioural features. New onset heightened interests or drives for GSES are not rare behavioural disturbances among patients with PD. Age, gender and duration of treatment with DAs have an independent and additive effect on the risk to develop such behavioural changes. Patients should be informed about potential treatment-associated behavioural changes.