Faculty Bibliography

OBJECTIVE: To determine whether ethyl-eicosapentaenoic acid (ethyl-EPA), an omega-3 fatty acid, improves the motor features of Huntington disease. DESIGN: Six-month multicenter, randomized, double-blind, placebo-controlled trial followed by a 6-month open-label phase without disclosing initial treatment assignments. SETTING: Forty-one research sites in the United States and Canada. PATIENTS: Three hundred sixteen adults with Huntington disease, enriched for a population with shorter trinucleotide (cytosine-adenine-guanine) repeat length expansions. INTERVENTIONS: Random assignment to placebo or ethyl-EPA, 1 g twice a day, followed by open-label treatment with ethyl-EPA. MAIN OUTCOME MEASURES: Six-month change in the Total Motor Score 4 component of the Unified Huntington's Disease Rating Scale analyzed for all research participants and those with shorter cytosine-adenine-guanine repeat length expansions (<45). RESULTS: At 6 months, the Total Motor Score 4 point change for patients receiving ethyl-EPA did not differ from that for those receiving placebo. No differences were found in measures of function, cognition, or global impression. Before public disclosure of the 6-month placebo-controlled results, 192 individuals completed the open-label phase. The Total Motor Score 4 change did not worsen for those who received active treatment for 12 continuous months compared with those who received active treatment for only 6 months (2.0-point worsening; P=.02). CONCLUSION: Ethyl-EPA was not beneficial in patients with Huntington disease during 6 months of placebo-controlled evaluation. Clinical Trial Registry clinicaltrials.gov Identifier: NCT00146211.

BACKGROUND: Communicating clinical trial results to research participants is seldom accomplished in a timely or an effective manner. OBJECTIVE: To evaluate the effectiveness of a plan to communicate results in an industry-sponsored randomized controlled trial for Huntington disease. DESIGN, SETTING, AND PARTICIPANTS: Postal survey to research participants at 28 of 41 research sites (including 217 of 316 participants) in Canada and the United States. INTERVENTION: We communicated trial results by means of (1) a media release from the investigators within a day after a sponsor-issued press release; (2) a subsequent telephone call from the site staff to the participants; and (3) a conference call for research participants 2 weeks after the results were released. MAIN OUTCOME MEASURES: Source and timing for learning study results and satisfaction with their communication. RESULTS: Of the 217 study participants surveyed, 114 (52.5%) responded. Most (73.1%) first learned the study results from their site's telephone call, and 46.3% learned the results within 1 day of the sponsor's press release. Participants reported high or complete satisfaction with the site telephone call (89.3%) and conference call (82.1%) but relatively low satisfaction with the sponsor's press release (50.0%). Most respondents reported good understanding of the risks and benefits of the experimental treatment and the next steps for their participation. CONCLUSION: Surveyed research participants learned of the clinical trial results soon after public release and highly valued the personalized and accurate communication efforts by the study investigators.

OBJECTIVE: In this case report, we present a patient with normal pressure hydrocephalus in whom a lumbar drainage trial yielded a false-negative result secondary to cervical spondylosis. CLINICAL PRESENTATION: An 80-year-old woman presented with classic symptoms of normal pressure hydrocephalus as well as evidence of cervical myelopathy. Magnetic resonance imaging of the brain and spine showed enlarged ventricles and single-level cervical canal narrowing. INTERVENTION: An initial lumbar drainage trial was performed, which revealed negative results. The patient then underwent cervical decompression and fusion. Despite this procedure, the patient's symptoms continued to worsen. A repeat lumbar drainage trial was performed with positive results. Subsequently, a ventriculoperitoneal shunt was placed, resulting in significant improvement of her symptoms. CONCLUSION: This case report illustrates how altered cerebrospinal fluid flow dynamics may impact the accuracy of the lumbar spinal drainage trial in patients with normal pressure hydrocephalus.

Movement disorder emergencies include any movement disorder which evolves over hours to days, in which failure to appropriately diagnose and manage can result in patient morbidity or mortality. It is crucial that doctors recognize these emergencies with accuracy and speed by obtaining the proper history and by being familiar with the phenomenology of frequently encountered movements. These disorders will be discussed based on the most common associated involuntary movement, either parkinsonism, dystonia, chorea, tics or myoclonus, and, when available, review the workup and treatment options based on the current literature.

Focal task-specific dystonia of the musicians' hand (FTSDmh) is an occupational movement disorder that affects instrumental musicians and often derails careers. There has been speculation on the role of intense practice or the specific technical demands of various instruments as triggers for the development of FTSDmh. In this study, we review the clinical features of all published cases (899 patients) and 61 previously unpublished cases of FTSDmh. Our primary goals were to search for patterns in the clinical phenotype, and to discern if specific instrumental technical demands might be related to the development of dystonia. Symptoms of FTSDmh began at a mean age 35.7 years (SD = 10.6), with an overwhelming male predominance (M:F = 4.1:1). The right hand was preferentially affected in keyboard and plucked string players (77%), and the left hand in bowed string players (68%). Flexion movements were the most common dystonic movement in each instrument class, and fingers 3, 4, and 5, either in isolation or combination, were most frequently involved. The clinical implications of these findings and their possible relationship to the pathophysiology of focal task-specific dystonia are explored.

Myoclonus is a hyperkinetic movement disorder characterized by quick, involuntary jerks. It encompasses a vast range of etiologies and widespread anatomic locations. Treatment frequently requires multiple agents and is often only partially beneficial. These patients pose a considerable challenge for the clinician, further complicated by the fact that many of the treatment choices lack evidence-based support. In the past few years, publications regarding therapy have been largely observational case reports or series. Although the literature on treatment of cortical myoclonus appears to be growing, evidence regarding myoclonus of noncortical origin is less well established. Investigation of more satisfactory treatments is needed, as this condition can be disturbing, debilitating, and sometimes harmful for patients. Continuing investigations are using various animal models (mostly of posthypoxic myoclonus), electrophysiologic studies, new imaging techniques such as diffusion tensor imaging, and genetic studies. Meanwhile, the clinical approach to diagnosing and classifying myoclonus remains largely unchanged. This review updates readers on current investigations and suggests guidelines for diagnosing and treating myoclonus.

Spatial covariance analysis has been used with (18)F-fluorodeoxyglucose (FDG) PET to detect and quantify specific metabolic patterns associated with Parkinson's disease (PD). However, PD-related patterns cannot necessarily serve as biomarkers of the processes that underlie the atypical parkinsonian syndromes. In this FDG PET study, we used strictly defined statistical criteria to identify disease-related metabolic patterns in the imaging data from patients with multiple system atrophy (MSA) and progressive supranuclear palsy (PSP), the two most common of these atypical conditions. We found that MSA and PSP were each associated with a specific, highly stable metabolic brain network (P < 0.0001, bootstrap estimation). The MSA-related pattern was characterized by decreased metabolism in the putamen and cerebellum. The PSP-related pattern was characterized by metabolic decreases in the brainstem and medial frontal cortex. For both conditions, pattern expression was significantly elevated in patients relative to age-matched healthy control subjects (P < 0.001). For each condition, we validated the associated disease-related metabolic pattern by computing its expression on an individual scan basis in two independent patient cohorts, and in one subsequent healthy volunteer cohort. We found that for both MSA and PSP, prospective assessments of pattern expression accurately discriminated patients from controls (P < 0.001). These findings suggest that the major atypical parkinsonian syndromes are associated with distinct patterns of abnormal regional metabolic activity. These disease-related networks can potentially be used in conjunction with functional brain imaging as quantifiable biomarkers for the assessment of these pathological conditions

OBJECTIVE: To estimate the risk of Parkinson disease (PD) in individuals with mutations in the Parkin gene. DESIGN: We assessed point mutations and exon deletions and duplications in the Parkin gene in 247 probands with PD (age at onset < or =50 years) and 104 control probands enrolled in the Genetic Epidemiology of Parkinson's Disease (GEPD) study. For each first-degree relative, a consensus diagnosis of PD was established. The probability that each relative carried a mutation was estimated from the proband's Parkin carrier status using Mendelian principles and from the relationship of the relative to the proband. SETTING: Tertiary care movement disorders center. Patients Cases, controls, and their first-degree relatives were enrolled in the GEPD study. MAIN OUTCOME MEASURES: Estimated age-specific penetrance in first-degree relatives. RESULTS: Parkin mutations were identified in 25 probands with PD (10.1%), 18 (72.0%) of whom were heterozygotes. One Parkin homozygote was reported in 2 siblings with PD. The cumulative incidence of PD to age 65 years in carrier relatives (age-specific penetrance) was estimated to be 7.0% (95% confidence interval, 0.4%-71.9%), compared with 1.7% (95% confidence interval, 0.8%-3.4%) in noncarrier relatives of the cases (P = .59) and 1.1% (95% confidence interval, 0.3%-3.4%) in relatives of the controls (compared with noncarrier relatives, P = .52). CONCLUSIONS: The cumulative risk of PD to age 65 years in a noncarrier relative of a case with an age at onset of 50 years or younger is not significantly greater than the general population risk among controls. Age-specific penetrance among Parkin carriers, in particular heterozygotes, deserves further study.

Myoclonus-dystonia (M-D) due to SGCE mutations is characterized by early onset myoclonic jerks, often associated with dystonia. Penetrance is influenced by parental sex, but other sex effects have not been established. In 42 affected individuals from 11 families with identified mutations, we found that sex was highly associated with age at onset regardless of mutation type; the median age onset for girls was 5 years versus 8 years for boys (P < 0.0097). We found no association between mutation type and phenotype.