Stigma and Social Avoidance in Adults with Essential Tremor

Background

People with essential tremor (ET) can be subject to stigma, and some adopt avoidance behaviors. Characteristics associated with ET stigma and the relationship between perceived stigma and social dysfunction have not been studied.

Objectives

To discern predictors of perceived stigma and social dysfunction in ET, and to identify potentially treatable psychological factors associated with social dysfunction.

Methods

We surveyed ET patients (n = 158) on recalled stigma incidents and social dysfunction related to tremor, as well as clinical and demographic characteristics including tremor severity, and psychological constructs including anxiety, depression, mindfulness, resilience, and narcissism.

Results

Worse tremor severity (Standardized beta [SB] 1.4, P < 0.001) especially among younger participants (interaction of age and tremor severity SB -0.9, P < 0.001) and presence of vocal tremor (SB 0.7, P = 0.002) predict perceived stigma. 53/157 (33.8%) participants met criteria for social dysfunction, employing maladaptive avoidance strategies. Scores for perceived stigma (Odds Ratio [OR] 1.2, P = 0.002), depression (OR 1.5, P = 0.004) and stigma psychological distress (OR 1.2, P = 0.001) as well as sex (OR 4.3 for females, P = 0.045) predicted social dysfunction.

Conclusions

Depression and stigma psychological distress contribute to social dysfunction related to ET stigma. Treating these psychological factors may mitigate social avoidance behaviors prevalent among susceptible individuals: those who most perceive ET stigma, i.e. relatively younger patients with worse tremor or with vocal tremor, and in particular females who are more prone to social dysfunction than males with the same degree of perceived stigma.

Safety of the tau-directed monoclonal antibody BIIB092 in progressive supranuclear palsy: a randomised, placebo-controlled, multiple ascending dose phase 1b trial

BACKGROUND

Progressive supranuclear palsy is a rare neurodegenerative disease associated with dysfunctional tau protein. BIIB092 is a humanised monoclonal antibody that binds to N-terminal tau and is thus being assessed as a potential novel treatment for progressive supranuclear palsy. We aimed to investigate the safety and tolerability of BIIB092 in individuals with progressive supranuclear palsy.

METHODS

This 12-week, double-blind, randomised, placebo-controlled, multiple ascending dose, phase 1b trial was done at 13 outpatient sites in the USA. Participants aged 41-86 years with probable or possible progressive supranuclear palsy with a score of 20 or greater on the Mini-Mental State Examination (MMSE) were enrolled. Three BIIB092 dose escalation cohorts (150 mg, 700 mg, or 2100 mg; eight participants per cohort) were tested sequentially. For each dose cohort, the first two participants were randomly assigned by a computer-generated scheme to receive either BIIB092 or placebo intravenously every 4 weeks for 57 days. After 2 days, the six remaining participants in each cohort were randomly assigned (5:1) to receive BIIB092 or placebo for 57 days. An additional expansion panel of 24 patients was randomly assigned (3:1) to receive 2100 mg or placebo every 4 weeks for 57 days. All participants were followed up to day 85. The primary outcome was safety, which was analysed in the treated population (all enrolled participants who received at least one dose of the study drug). This trial is registered with ClinicalTrials.gov, NCT02460094.

FINDINGS

Between Oct 2, 2015, and Oct 19, 2016, 48 participants were enrolled and randomly assigned to the BIIB092 (n=36) and placebo (n=12) groups. No apparent demographic differences were observed between the two groups at baseline. All 48 participants completed the treatment phase of the study. Adverse events were generally mild to moderate in severity; the most common in the placebo and BIIB092 groups were falls (in two [17%] of 12 patients and in ten [28%] of 36 patients), urinary tract infections (in one [8%] of 12 and in six [17%] of 36), contusions (in one [8%] of 12 and in five [14%] of 36), and headaches (in none and in five [14%] of 36). Four serious adverse events resulting in admission to hospital were reported in three participants who received BIIB092 2100 mg: two severe adverse events of urinary tract infection, one severe adverse event of change in mental status, and one moderate adverse event of aspiration pneumonia. None was considered to be related to the study drug, all were resolved, and no deaths were reported.

INTERPRETATION

Repeated administration of the anti-tau monoclonal antibody BIIB092, at doses of up to 2100 mg, appears to be well tolerated in participants with progressive supranuclear palsy. Results of this phase 1b trial have informed the design of the ongoing phase 2 PASSPORT (NCT03068468) study to examine the efficacy and safety of BIIB092.

FUNDING

Bristol-Myers Squibb, Biogen.

A randomized, double-blind, placebo-controlled trial of coenzyme Q10 in Huntington disease

OBJECTIVE

To test the hypothesis that chronic treatment of early-stage Huntington disease (HD) with high-dose coenzyme Q10 (CoQ) will slow the progressive functional decline of HD.

METHODS

We performed a multicenter randomized, double-blind, placebo-controlled trial. Patients with early-stage HD (n = 609) were enrolled at 48 sites in the United States, Canada, and Australia from 2008 to 2012. Patients were randomized to receive either CoQ 2,400 mg/d or matching placebo, then followed for 60 months. The primary outcome variable was the change from baseline to month 60 in Total Functional Capacity score (for patients who survived) combined with time to death (for patients who died) analyzed using a joint-rank analysis approach.

RESULTS

An interim analysis for futility revealed a conditional power of <5% for the primary analysis, prompting premature conclusion in July 2014. No statistically significant differences were seen between treatment groups for the primary or secondary outcome measures. CoQ was generally safe and well-tolerated throughout the study.

CONCLUSIONS

These data do not justify use of CoQ as a treatment to slow functional decline in HD.

CLINICALTRIALSGOV IDENTIFIER

NCT00608881.

CLASSIFICATION OF EVIDENCE

This article provides Class I evidence that CoQ does not slow the progressive functional decline of patients with HD.

β-Hexachlorocyclohexane levels in serum and risk of Parkinson's disease

Pesticide exposure has been implicated as an environmental risk factor for the development of Parkinson's disease (PD). However, few studies have identified specific pesticides. Previously, we identified elevated serum levels of the organochlorine pesticide β-hexachlorocyclohexane (β-HCH) in PD patients from a small clinical sample. Here, we conducted a case-control study to confirm the association between β-HCH and PD in a larger sample size (n=283) with serum samples of PD patients and controls obtained from UT Southwestern Medical Center and Emory University. Samples were obtained from two discrete periods at both sites, 2001-2003 and 2006-2008, and were analyzed for β-HCH levels. Adjusted odds ratios (ORs) for PD were estimated using logistic regression and generalized estimating equations. The mean serum β-HCH level across all cohorts in this study was 22.3 ng/mg cholesterol (range: 0-376.7), and the levels were significantly higher and samples collected in 2001-2003 vs. 2006-2008. After controlling for age and gender, the OR for increased risk of PD for every 1 ng/mg increase in serum β-HCH ranged from 1.02 to 1.12 across the four different cohorts, and 1.03 (95% CI: 1.00-1.07, p value=0.031) in the pooled analysis. Furthermore, the OR for increased risk of PD of subjects having serum β-HCH levels above the inter-quartile range of 39.08 ng/mg cholesterol was 2.85 (95% CI: 1.8, 4.48; p value<0.001). These data are consistent with environmental decreases in β-HCH levels between 2001 and 2008, but they indicate that elevated levels of serum β-HCH are still associated with heightened risk for PD.

Elevated serum pesticide levels and risk of Parkinson disease

BACKGROUND

Exposure to pesticides has been reported to increase the risk of Parkinson disease (PD), but identification of the specific pesticides is lacking. Three studies have found elevated levels of organochlorine pesticides in postmortem PD brains.

OBJECTIVE

To determine whether elevated levels of organochlorine pesticides are present in the serum of patients with PD.

DESIGN

Case-control study.

SETTING

An academic medical center.

PARTICIPANTS

Fifty patients with PD, 43 controls, and 20 patients with Alzheimer disease.

MAIN OUTCOME MEASURES

Levels of 16 organochlorine pesticides in serum samples.

RESULTS

beta-Hexachlorocyclohexane (beta-HCH) was more often detectable in patients with PD (76%) compared with controls (40%) and patients with Alzheimer disease (30%). The median level of beta-HCH was higher in patients with PD compared with controls and patients with Alzheimer disease. There were no marked differences in detection between controls and patients with PD concerning any of the other 15 organochlorine pesticides. Finally, we observed a significant odds ratio for the presence of beta-HCH in serum to predict a diagnosis of PD vs control (odds ratio, 4.39; 95% confidence interval, 1.67-11.6) and PD vs Alzheimer disease (odds ratio, 5.20), which provides further evidence for the apparent association between serum beta-HCH and PD.

CONCLUSIONS

These data suggest that beta-HCH is associated with a diagnosis of PD. Further research is warranted regarding the potential role of beta-HCH as a etiologic agent for some cases of PD.

Risk factors for pathologic gambling and other compulsions among Parkinson’s disease patients taking dopamine agonists

Three hundred patients with Parkinson's disease taking dopamine agonists were surveyed for the presence of compulsions. Fifty-eight reported active compulsions which had developed after initiation of dopamine agonists. These included 25 with sexual compulsions and 28 with self-described compulsive gambling, of whom 17 met criteria for pathologic gambling. Males were over-represented. Patients with any compulsion and those with pathologic gambling were about 6 years younger than those without compulsions. These behavioral problems were not associated with an individual dopamine agonist, nor dose or duration, nor concomitant levodopa. Follow-up of the pathologic gamblers 1 year after intervention, which was cessation of the dopamine agonist in most cases, found ongoing but controlled gambling in five and complete cessation within 4 months in the remainder.

Serum biomarkers for Alzheimer's disease: proteomic discovery

For Alzheimer's disease (AD), the most common neurodegenerative disease, there is no simple, cost-effective biomarker for disease identification. Using novel mass spectrometry (MS)-based techniques, and analysis of the albumin-enriched low molecular weight proteome, minute amounts of human serum were analyzed for the measurement of thousands of peptides and proteins in parallel. The mass spectrograms were then evaluated with a novel computer algorithm to identify spectral peaks that discriminate between samples from patients with and without AD. There are four peaks that distinguish AD from control subjects and AD subjects from those with Parkinson's disease (PD). Additionally, after analyzing data from a recently published study of AD and control subjects, we found three discriminating peaks in common with the four from our patient serum samples. The identification of these peptides/proteins, and their direct measurement in patient serum, may allow the development of a simple, cost-effective test for AD.

Movement Disorders After Head Injury

Head injury can cause extrapyramidal movement disorders such as tremors, parkinsonism, dystonia, chorea, myoclonus, and tics. Pure adventitious movements are rare, but combinations with paresis, spasticity, apraxia, or ataxia occur in approximately 20% of cases of severe head injury, in many cases appearing or evolving in the months following the injury. Tremors may improve in time but many of the other syndromes tend to persist. Reversible causes such as medications or metabolic derangements are occasionally identifiable. Some of these adventitious movements can be improved using neuroactive drugs, botulinum toxin injections, or stereotactic brain surgery.

Rapidly progressive parkinsonism in a self-reported user of Ecstasy and other drugs

A 38-year-old man developed parkinsonism that progressed to Hoehn and Yahr stage 5 within 4 years of onset. Response to ropinirole deteriorated, levodopa was not tolerated, and subthalamic nucleus stimulation has provided only partial relief of symptoms. He reported heavy use of Ecstasy through most of his twenties and thirties. His neurological problems may be unrelated to his drug use, but it is also possible they represent an idiosyncratic reaction.

Accuracy of clinical detection of INO in MS: Corroboration with quantitative infrared oculography

The authors compared the accuracy of clinical detection (by 279 physician observers) of internuclear ophthalmoparesis (INO) with that of quantitative infrared oculography. For the patients with mild adduction slowing, INO was not identified by 71%. Intermediate dysconjugacy was not detected by 25% of the evaluators. In the most severe cases, INO was not identified by only 6%. Oculographic techniques significantly enhance the precision of INO detection compared to the clinical exam.

A randomized trial of amantadine in Huntington disease

CONTEXT

Huntington chorea, like levodopa-induced dyskinesias, may be responsive to amantadine hydrochloride treatment.

OBJECTIVES

To measure the effect of amantadine treatment on Huntington chorea and to test a hypothesis that the adventitious movements are associated with reduced central proprioception that can be corrected by amantadine treatment.

DESIGN

A randomized placebo-controlled cross-over trial with 2 weeks of treatment.

SETTING

A tertiary referral center.

PARTICIPANTS

Twenty-four subjects with Huntington disease took amantadine hydrochloride, 100 mg 3 times daily for 2 weeks, and placebo for 2 weeks.

METHODS

Chorea of the face, trunk, and limbs while seated was videotaped at baseline and after each study phase. Segments were viewed in random order by blinded reviewers and scored. Proprioception was determined using arm restraints in which the right and left elbows were set at slightly different angles, and the errors in selecting the more extended elbow over 40 trials were recorded.

RESULTS

The chorea score was not correlated with a proprioception deficit. Neither chorea nor proprioception were significantly affected by amantadine therapy. The chorea score was 9.6 (3.1) points at baseline and 9.7 (3.7) points when the patient was receiving amantadine therapy. The 95% confidence interval for the difference between placebo effect and amantadine effect was -1.43 to 1.0 points. Despite this, 19 subjects felt improved during the amantadine phase compared with 6 subjects improved in the placebo phase (P =.006) and the quality of life was better (P<.001).

CONCLUSIONS

Elbow proprioception was not shown to be related to Huntington chorea. Amantadine hydrochloride treatment at doses of 300 mg/d had no effect, on average, for Huntington chorea, although most patients felt subjectively better during the short course of amantadine treatment.

A new measure of dysconjugacy in INO: the first-pass amplitude

BACKGROUND

The ratios of abducting to adducting eye movements (versional dysconjugacy index, VDI) for saccadic velocity and acceleration have been useful measures by which to objectively characterize internuclear ophthalmoparesis (INO). Amplitude measures of dysconjugacy have been less useful, given that many patients maintain the ability to ultimately reach a centrifugal fixation target and that traditional amplitude measures of VDI have focused on this 'final amplitude' (FA) position.

METHODS

We utilized infrared oculography to define a new amplitude measure of dysconjugacy in 42 multiple sclerosis (MS) patients with INO. The first-pass amplitude (FPA)-VDI is the ratio of abduction/adduction eye movement amplitudes computed at the time when the abducting eye initially achieves the centrifugal horizontal fixation target.

RESULTS

FPA-VDI values were significantly more sensitive and specific than FA-VDI values in demonstrating dysconjugacy in INO, and there was a 14-fold increase in dysconjugacy as measured by FPA-VDI Z-scores when compared to FA-VDI Z-scores.

CONCLUSION

Consideration of velocity (pulse) and amplitude (step) components of dysconjugacy in patients with INO can provide a greater understanding of the dynamic aspects of this syndrome. We propose to characterize the relationship between the pathophysiology of INO and neuroradiologic measures of tissue injury in MS.

Quantitative oculographic characterisation of internuclear ophthalmoparesis in multiple sclerosis: the versional dysconjugacy index Z score

BACKGROUND

There is a poor correlation between multiple sclerosis disease activity, as measured by magnetic resonance imaging, and clinical disability.

OBJECTIVE

To establish oculographic criteria for the diagnosis and severity of internuclear ophthalmoparesis (INO), so that future studies can link the severity of ocular dysconjugacy with neuroradiological abnormalities within the dorsomedial brain stem tegmentum.

METHODS

The study involved 58 patients with multiple sclerosis and chronic INO and 40 normal subjects. Two dimensional infrared oculography was used to derive the versional dysconjugacy index (VDI)-the ratio of abducting to adducting eye movements for peak velocity and acceleration. Diagnostic criteria for the diagnosis and severity of INO were derived using a Z score and histogram analysis, which allowed comparisons of the VDI from multiple sclerosis patients and from a control population.

RESULTS

For a given saccade, the VDI was typically higher for acceleration v velocity, whereas the Z scores for velocity measures were always higher than values derived from comparable acceleration VDI measures; this was related to the greater variability of acceleration measures. Thus velocity was a more reliable measure from which to determine Z scores and thereby the criteria for INO and its level of severity. The mean (SD) value of the VDI velocity derived from 40 control subjects was 0.922 (0.072). The highest VDI for velocity from a normal control subject was 1.09, which was 2.33 SD above the normal control mean VDI. We therefore chose 2 SD beyond this value (that is, a Z score of 4.33) as the minimum criterion for the oculographic confirmation of INO. Of patients thought to have unilateral INO on clinical grounds, 70% (16/23) were found to have bilateral INO on oculographic assessment.

CONCLUSIONS

INO can be confirmed and characterised by level of severity using Z score analysis of quantitative oculography. Such assessments may be useful for linking the level of severity of a specific clinical disability with neuroradiological measures of brain tissue pathology in multiple sclerosis.

Randomized trial comparing primidone initiation schedules for treating essential tremor

Early side effects are common when primidone is used to treat essential tremor, with as many as one-third of patients failing to tolerate the tablets. Lower doses can be prescribed initially using a suspension formulation. We suspected suspension initiation would result in fewer early side effects, allow better acclimatization, and improve compliance. Forty patients with essential tremor were randomized to begin primidone treatment using either 2.5 mg doses in the suspension form or 25 mg doses in the tablet form. Doses gradually increased over 3 weeks to 150 mg/day. This was a double-blind, double-dummy trial. Medication cessation due to side effects was designated the primary end-point. Four patients in the suspension group and two in the tablet group dropped out due to early side effects, resulting in a relative risk of 1.9 (95% confidence interval 0.4 to 9.2). Side effects in the first 48 hours of treatment were equally common, affecting seven subjects in each group. Treatment benefits were the same in both groups. We concluded that use of a very low initial dose and a graduated titration schedule in suspension formulation did not appear to improve primidone tolerability. If anything, compliance tended to be worse when compared with the tablet formulation, though the study was under-powered to reject the null hypothesis of equivalence.

Proprioception in Parkinson's disease is acutely depressed by dopaminergic medications

OBJECTIVES

Impaired proprioception has been previously reported in patients with Parkinson's disease. It was hypothesised that dopaminergic medications transiently depress proprioception, with amplification of adventitious movements as a result. This study tested for effects on proprioception of dopaminergic drugs, and for associations between such effects and drug induced dyskinesias.

METHODS

In 17 patients with Parkinson's disease, arm proprioception was tested in the practically defined "off" state, and retested 1 hour after taking levodopa or dopamine agonist. Testing consisted of side to side comparison of elbow angle, matching the contralateral elbow angle, and spatial recall of an unrestrained arm.

RESULTS

Proprioception deteriorated as hypothesised, reaching significance by one tailed t test for each of the three tasks. The relative deterioration (and the 95% lower confidence bound for estimated deterioration) was 31% (4%) for side to side elbow comparison, was 27% (11%) for accuracy in matching the contralateral elbow angle, and was 11% (0%) for spatial recall. Dyskinetic (n=6) and non-dyskinetic (n=11) patients did not differ significantly in these effects on proprioception. Control subjects (n=6) and untreated parkinsonian subjects (n=5) did not significantly differ from the parkinsonian patients in the off state.

CONCLUSIONS

Administration of levodopa and dopamine agonists were associated with a modest acute suppression in central responsiveness to joint position. It is speculated that compensatory exaggerated movement could account in part for the phenomenon of drug induced dyskinesias.

Spinocerebellar ataxia type 3 phenotypically resembling parkinson disease in a black family

BACKGROUND

Machado-Joseph disease (MJD), also known as spinocerebellar ataxia type 3 (SCA3), can present with parkinsonism. However, classically, atypical features, including pyramidal and cerebellar signs, peripheral neuropathy, and/or anterior horn cell dysfunction, are also seen. Levodopa responsiveness is unusual in this disorder.

OBJECTIVE

To determine the cause of apparent parkinsonism suggestive of Parkinson disease (PD) in a large family of African origin.

METHODS

We studied a large family in which apparent autosomal dominant parkinsonism suggestive of PD occurs in order to find the causal genetic mutation. Affected and unaffected family members were screened for the presence of a pathogenic expansion at the MJD/SCA3 locus using a polymerase chain reaction polyacrylamide gel electrophoresis-based assay.

RESULTS

Three of the 4 individuals who were examined have a phenotype reminiscent of PD. Specifically, they have at least 2 of the cardinal features, are levodopa responsive, and have no atypical features. All affected family members were shown to possess pathogenic expansions in the MJD/SCA3 gene.

CONCLUSIONS

Parkinsonism suggestive of PD due to MJD/SCA3 has not been previously reported, to our knowledge. However, atypical, though also levodopa-responsive, parkinsonism has been previously reported to occur in African American families, suggesting that that this phenotype is associated with African ancestry. In this regard, it is perhaps significant that all the individuals with parkinsonism have relatively low numbers of repeats (normal, 16-34; pathologic, 60-84). In families in which linkage analysis is being performed to determine a locus for autosomal dominant parkinsonism suggestive of PD, evaluation for the MJD/SCA3 mutation is indicated.

Autonomic dysfunction in the Lambert-Eaton myasthenic syndrome: serologic and clinical correlates

Autonomic dysfunction is a recognized feature of the Lambert-Eaton myasthenic syndrome (LES). However, the characteristic pattern of dysautonomia has not been clearly documented and its pathophysiologic basis is not known. We therefore abstracted autonomic symptomatology and results of quantitative tests for salivation, and vasomotor, cardiovagal, and sudomotor reflexes from records of 30 LES patients. Dry mouth (77%) and impotence (45% of men) were the most common symptoms. Composite Autonomic Scoring Scale results were abnormal in 93% of patients, and autonomic failure was severe in 20%. The frequency of specific test abnormalities were the following: sudomotor function, 83%; cardiovagal reflexes, 75%; salivation, 44%; and adrenergic function, 37%. Although voltage-gated N-type calcium (Ca2+) channels are implicated in autonomic transmission, the low frequency of serum antibodies to N-type Ca2+ channels found in the patients of this study (31% positive) argues against a pathogenic role in mediating LES-related dysautonomia. In contrast, 93% of the patients were seropositive for P/Q-type Ca2+ channel antibodies. A subset of these antibodies is thought to impair neuromuscular transmission. Autoantibodies of thyrogastric or glutamic acid decarboxylase specificity (markers of predisposition to type 1 diabetes mellitus) were found in 45% of patients, and type 1 antineuronal nuclear antibody (or anti-Hu, a marker of autoimmune neuropathy associated with small-cell lung carcinoma) was found in 3%. No autoantibody correlated with autonomic dysfunction severity. Sensorimotor neuropathy was documented in five patients, and was not significantly associated with autonomic neuropathy. Autonomic failure was most severe in older subjects with cancer (p = 0.02, age by cancer interaction).