Trial of Prasinezumab in Early-Stage Parkinson's Disease.

BACKGROUND: Aggregated α-synuclein plays an important role in the pathogenesis of Parkinson's disease. The monoclonal antibody prasinezumab, directed at aggregated α-synuclein, is being studied for its effect on Parkinson's disease. METHODS: In this phase 2 trial, we randomly assigned participants with early-stage Parkinson's disease in a 1:1:1 ratio to receive intravenous placebo or prasinezumab at a dose of 1500 mg or 4500 mg every 4 weeks for 52 weeks. The primary end point was the change from baseline to week 52 in the sum of scores on parts I, II, and III of the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS; range, 0 to 236, with higher scores indicating greater impairment). Secondary end points included the dopamine transporter levels in the putamen of the hemisphere ipsilateral to the clinically more affected side of the body, as measured by 123I-ioflupane single-photon-emission computed tomography (SPECT). RESULTS: A total of 316 participants were enrolled; 105 were assigned to receive placebo, 105 to receive 1500 mg of prasinezumab, and 106 to receive 4500 mg of prasinezumab. The baseline mean MDS-UPDRS scores were 32.0 in the placebo group, 31.5 in the 1500-mg group, and 30.8 in the 4500-mg group, and mean (±SE) changes from baseline to 52 weeks were 9.4±1.2 in the placebo group, 7.4±1.2 in the 1500-mg group (difference vs. placebo, -2.0; 80% confidence interval [CI], -4.2 to 0.2; P = 0.24), and 8.8±1.2 in the 4500-mg group (difference vs. placebo, -0.6; 80% CI, -2.8 to 1.6; P = 0.72). There was no substantial difference between the active-treatment groups and the placebo group in dopamine transporter levels on SPECT. The results for most clinical secondary end points were similar in the active-treatment groups and the placebo group. Serious adverse events occurred in 6.7% of the participants in the 1500-mg group and in 7.5% of those in the 4500-mg group; infusion reactions occurred in 19.0% and 34.0%, respectively. CONCLUSIONS: Prasinezumab therapy had no meaningful effect on global or imaging measures of Parkinson's disease progression as compared with placebo and was associated with infusion reactions. (Funded by F. Hoffmann-La Roche and Prothena Biosciences; PASADENA ClinicalTrials.gov number, NCT03100149.).

Potential Therapeutic Application for Nicotinic Receptor Drugs in Movement Disorders.

Emerging studies indicate that striatal cholinergic interneurons play an important role in synaptic plasticity and motor control under normal physiological conditions, while their disruption may lead to movement disorders. Here we discuss the involvement of the cholinergic system in motor dysfunction, with a focus on the role of the nicotinic cholinergic system in Parkinson's disease and drug-induced dyskinesias. Evidence for a role for the striatal nicotinic cholinergic system stems from studies showing that administration of nicotine or nicotinic receptor drugs protects against nigrostriatal degeneration and decreases L-dopa-induced dyskinesias. In addition, nicotinic receptor drugs may ameliorate tardive dyskinesia, Tourette's syndrome and ataxia, although further study is required to understand their full potential in the treatment of these disorders. A role for the striatal muscarinic cholinergic system in movement disorders stems from studies showing that muscarinic receptor drugs acutely improve Parkinson's disease motor symptoms, and may reduce dyskinesias and dystonia. Selective stimulation or lesioning of striatal cholinergic interneurons suggests they are primary players in this regulation, although multiple central nervous systems appear to be involved. IMPLICATIONS: Accumulating data from preclinical studies and clinical trials suggest that drugs targeting CNS cholinergic systems may be useful for symptomatic treatment of movement disorders. Nicotinic cholinergic drugs, including nicotine and selective nAChR receptor agonists, reduce L-dopa-induced dyskinesias, as well as antipsychotic-induced tardive dyskinesia, and may be useful in Tourette's syndrome and ataxia. Subtype selective muscarinic cholinergic drugs may also provide effective therapies for Parkinson's disease, dyskinesias and dystonia. Continued studies/trials will help address this important issue.

Long-term safety and efficacy of levodopa-carbidopa intestinal gel in advanced Parkinson's disease.

BACKGROUND: Levodopa-carbidopa intestinal gel (designated as carbidopa-levodopa enteral suspension in the United States) provides stable plasma levodopa concentrations and reduces motor fluctuations in advanced Parkinson's disease patients through continuous delivery of levodopa via percutaneous endoscopic gastrojejunostomy. We report long-term safety and efficacy outcomes from an open-label phase 3 treatment program. METHODS: PD patients (n = 262) who completed a 12-week double-blind study and its 52-week open-label extension or a separate 54-week open-label study were enrolled in this ongoing phase 3 open-label, multinational study (NCT00660673). Safety and efficacy assessments were collected every 6 months. RESULTS: Mean total duration of exposure to levodopa-carbidopa intestinal gel was 4.1 years (range, 1.2 to 6.9 years). The overall discontinuation rate was 34% (average annual discontinuation rate, 10%). Although most patients (94%) reported an adverse event, the rate of adverse events decreased over time; 53% experienced a serious adverse event. Of patients in this extension study, 54% required jejunal tube replacement during the study, and 37% required percutaneous endoscopic gastrostomy tube replacement. Most patients were on levodopa monotherapy. Patients maintained reductions in "off" time and increases in mean "on" time without dyskinesia from initial levodopa-carbidopa intestinal gel infusion to he study end point (P < 0.001; n = 81). Activities of daily living and quality-of-life assessments demonstrated significant improvements that persisted through the study. CONCLUSIONS: This long-term study demonstrates sustained and clinically meaningful benefits from levodopa-carbidopa intestinal gel in advanced PD patients. Although adverse event rates decreased over time, vigilance is required for device-related complications and adverse events. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Effect of levodopa-carbidopa intestinal gel on dyskinesia in advanced Parkinson's disease patients.

OBJECTIVE: The purpose of this study was to assess the effect of levodopa-carbidopa intestinal gel (carbidopa-levodopa enteral suspension) in advanced Parkinson's disease patients with troublesome dyskinesia. METHODS: Post hoc analyses of patient data from a 12-week, randomized, double-blind study and a 54-week open-label study were performed. Efficacy was assessed in the subgroup of patients defined by ≥1 hour of "on" time with troublesome dyskinesia at baseline as recorded in Parkinson's disease symptom diaries (double blind: n = 11 levodopa-carbidopa intestinal gel, n = 12 oral levodopa-carbidopa; open label: n = 144 levodopa-carbidopa intestinal gel). The changes in "off" time, "on" time with and without troublesome dyskinesia, and the overall safety and tolerability of levodopa-carbidopa intestinal gel were analyzed. RESULTS: Although not significantly different from oral levodopa treatment (P > .05) in the double-blind study, levodopa-carbidopa intestinal gel treatment resulted in a reduction from baseline in "on" time with troublesome dyskinesia (mean [standard deviation] hours: baseline = 3.1 [1.7], change from baseline to final = -1.8 [1.8], P = .014), increase in "on" time without troublesome dyskinesia (baseline = 7.4 [2.2], change = 4.4 [3.6], P = .004), and decrease in "off" time (baseline = 5.5 [1.3], change = -2.7 [2.8], P = .015). Similar trends were found in the open-label study. An increase in levodopa-carbidopa intestinal gel dose was not significantly correlated with increased "on" time with troublesome dyskinesia in either study (double blind: r = -.073, P = .842; open label: r = -0.001, P = .992). Adverse events were usually mild to moderate in severity and related to the gastrointestinal procedure. CONCLUSION: Our exploratory analyses suggest that optimizing levodopa delivery with levodopa-carbidopa intestinal gel may reduce troublesome dyskinesia in advanced Parkinson's disease.

Integrated safety of levodopa-carbidopa intestinal gel from prospective clinical trials.

BACKGROUND: Continuous administration of levodopa-carbidopa intestinal gel (carbidopa-levodopa enteral suspension) through a percutaneous endoscopic gastrojejunostomy is a treatment option for advanced Parkinson disease (PD) patients with motor fluctuations resistant to standard oral medications. Safety data from 4 prospective studies were integrated to assess the safety of this therapy. METHODS: Safety data from 4 studies were summarized using 2 overlapping data sets, permitting the separation of procedure/device-associated (n = 395) from non-procedure/device adverse events (n = 412). RESULTS: At the data cutoff, median exposure to levodopa-carbidopa intestinal gel was 911 days (range, 1-1980 days) with 963 total patient-years of exposure. Procedure/device adverse events occurred in 300 patients (76%), and serious adverse events occurred in 68 (17%); most frequently reported procedure/device adverse events and serious adverse events were complications of device insertion (41% and 8%, respectively) and abdominal pain (36% and 4%, respectively). Non-procedure/device adverse events occurred in 92% (379), with most frequently reported being insomnia (23%) and falls (23%); 42% (171) had non-procedure/device serious adverse events, with most frequently reported being pneumonia (5%) and PD symptoms (2%). Adverse events led to discontinuation in 17% (72), most frequently because of complication of device insertion (2.4%). There were 34 treatment-emergent deaths (8.3%) in the overlapping data sets, 2 of which (0.5%) were considered "possibly related" to the treatment system. CONCLUSION: In the largest collection of levodopa-carbidopa intestinal gel safety data from prospective clinical studies, procedure/device events were frequently reported and occasionally life threatening. Most non-procedure/device events were typical for levodopa treatment and an elderly population. These factors combined with high treatment efficacy led to a relatively low discontinuation rate in advanced PD patients.

Parkinson's disease.

Parkinson's disease (PD) is the most common age-related motoric neurodegenerative disease initially described in the 1800's by James Parkinson as the 'Shaking Palsy'. Loss of the neurotransmitter dopamine was recognized as underlying the pathophysiology of the motor dysfunction; subsequently discovery of dopamine replacement therapies brought substantial symptomatic benefit to PD patients. However, these therapies do not fully treat the clinical syndrome nor do they alter the natural history of this disorder motivating clinicians and researchers to further investigate the clinical phenotype, pathophysiology/pathobiology and etiology of this devastating disease. Although the exact cause of sporadic PD remains enigmatic studies of familial and rare toxicant forms of this disorder have laid the foundation for genome wide explorations and environmental studies. The combination of methodical clinical evaluation, systematic pathological studies and detailed genetic analyses have revealed that PD is a multifaceted disorder with a wide-range of clinical symptoms and pathology that include regions outside the dopamine system. One common thread in PD is the presence of intracytoplasmic inclusions that contain the protein, α-synuclein. The presence of toxic aggregated forms of α-synuclein (e.g., amyloid structures) are purported to be a harbinger of subsequent pathology. In fact, PD is both a cerebral amyloid disease and the most common synucleinopathy, that is, diseases that display accumulations of α-synuclein. Here we present our current understanding of PD etiology, pathology, clinical symptoms and therapeutic approaches with an emphasis on misfolded α-synuclein.

Pallidal stimulation-induced psychosis and suicidality in Parkinson's disease.

Neuropsychiatric adverse events have been previously reported following deep brain stimulation (DBS) for Parkinson's disease (PD). Most cases described have involved DBS of the subthalamic nucleus (STN). We report a unique case of acute-onset and reversible psychosis, suicidality, and depressive symptoms following DBS of the globus pallidus internus (GPi) and review the relevant literature.

Transdermal Nicotine Treatment and Progression of Early Parkinson's Disease.

BACKGROUND: Epidemiologic studies show that smokers have a lower incidence of Parkinson's disease. Nicotine has been hypothesized to slow progression in early Parkinson's disease. METHODS: In a double-blind, placebo-controlled multicenter trial, we randomly assigned patients with Parkinson's disease, diagnosed within 18 months, who were in Hoehn and Yahr disease stage less than or equal to 2 (range from 0 to 5; higher scores indicate greater impairment), who were therapy naïve (except for stable monoamine-oxidase-B inhibition), and not requiring dopaminergic therapy, to transdermal nicotine or placebo. The primary end point was change in Unified Parkinson's Disease Rating Scale parts I­III (Total UPDRS) score (range from 0 to 172; higher scores indicate greater impairment) between baseline and 60 weeks (52 weeks of trial therapy, 8 weeks of washout). The first secondary end point was change in Total UPDRS from baseline to 52 weeks. Differences between groups were estimated using the Hodges­Lehmann (HL) method and tested with the exact two-sided stratified Mann­Whitney­Wilcoxon test according to the intention-to-treat principle. RESULTS: Among 163 participants, 101 were assessed for the primary end point. Mean worsening of Total UPDRS was 3.5 in the placebo versus 6.0 in the nicotine group (HL-difference with 95% CI: ­3 [­6 to 0], P=0.06). For the first secondary end point, analysis of 138 participants showed a mean worsening of 5.4 in the placebo versus 9.1 in the nicotine group (HL-difference with 95% CI: ­4 [­7 to ­1]). Dropout was mainly because of early treatment discontinuation or adverse events. Cutaneous adverse effects at the patch application site were common. In all, 34.6% of participants initiated dopaminergic therapy during participation. CONCLUSIONS: One-year transdermal nicotine treatment did not slow progression in early Parkinson's disease. (Funded by the Michael J. Fox Foundation for Parkinson's Research and others; ClinicalTrials.gov number, NCT01560754; EudraCT number, 2010-020299-42.)

Prevalence and Relationship of Rest Tremor and Action Tremor in Parkinson's Disease.

Background: Despite the significance of tremor in Parkinson's disease (PD) diagnosis, classification, and patient's quality of life, there is a relative lack of data on prevalence and relationship of different tremor types in PD. Methods: The presence of rest tremor (RT) and action tremor (AT; defined as combination of both postural and kinetic tremor) was determined and RT severity was defined using the Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) at baseline in the Progression Marker Initiative (PPMI, n = 423), the Fox Investigation for New Discovery of Biomarkers (BioFIND, n = 118) and the Parkinson's Disease Biomarkers Program (PDBP, n = 873) cohorts. Results: Across baseline data of all three cohorts, RT prevalence (58.2%) was higher than AT prevalence (39.0%). Patients with RT had significantly higher (Chi-square test, p < 0.05) prevalence of AT compared to patients without RT in the PPMI (40.0% versus 30.1%), BioFIND (48.0% versus 40.0%) and PDBP (49.9% versus 21.0%) cohorts. Furthermore, patients with AT had significantly (Student t-test, p < 0.05) higher RT severity that those without AT in PPMI (5.7 ± 5.4 versus 3.9 ± 3.3), BioFIND, 6.4 ± 6.3 versus 3.8 ± 4.4) and PDBP (6.4 ± 6.6 versus 3.7 ± 4.4) cohorts. In the BioFIND cohort, the prevalence of all types of tremor and their combinations significantly decreased from the off-state to on-state. Discussion: The RT is the most frequent tremor type and present in more than half of the PD patients. However, AT is also present in nearly one-third of the PD patients. Our results also indicate that RT and AT may have cross-interactions in PD, and that dopaminergic treatment influences both RT and AT.

A post hoc comparison of levodopa-carbidopa intestinal gel daytime monotherapy vs polytherapy safety and efficacy in patients with advanced Parkinson's disease: Results from 6 phase 3/3b open-label studies.

INTRODUCTION: As Parkinson's disease (PD) progresses, the number/frequency of PD medications tend to increase, which is correlated with decreased patient compliance and suboptimal control of PD symptoms. We investigated efficacy and safety of levodopa-carbidopa intestinal gel (LCIG) daytime monotherapy (with or without nighttime oral levodopa-carbidopa) compared with polytherapy (LCIG with ≥1 adjunctive PD therapy) in advanced PD patients. METHODS: This post hoc descriptive study compared LCIG stable daytime monotherapy with LCIG stable polytherapy in all six phase 3/3b open-label studies from both US and international sites; because of study design variability, pooling data for comparison was not appropriate. Efficacy assessments included PD diary data (mean change from baseline in "Off" time and "On" time with or without troublesome dyskinesia), mean Unified PD Rating Scale scores (Parts II and III), and 39-item Parkinson's Disease Questionnaire (PDQ-39) summary index. Adverse events were also assessed. RESULTS: Overall, LCIG daytime monotherapy and polytherapy demonstrated similar efficacy/safety profiles in advanced PD patients, regardless of treatment duration or population. LCIG monotherapy vs. polytherapy groups experienced similar mean decreases in "Off" time (4.6 vs. 4.1 h/day) and similar increases in "On" time without troublesome dyskinesia (4.6 vs. 4.1 h/day). In most studies, PDQ-39 summary index scores were reduced from baseline by ≥5 points, regardless of patient population or study duration. Adverse events not related to the procedure/device were similar in both groups. CONCLUSION: Our data suggest that, for appropriate patients, LCIG monotherapy can provide a more simplified treatment option with similar efficacy and safety.

Safety of Levodopa-Carbidopa Intestinal Gel Treatment in Patients with Advanced Parkinson's Disease Receiving ≥2000 mg Daily Dose of Levodopa.

BACKGROUND: Levodopa-carbidopa intestinal gel (LCIG) provides continuous levodopa administration and clinical benefits to patients with advanced Parkinson's disease (PD). This report evaluates long-term safety and efficacy of high-dose LCIG in PD patients. METHODS: Data were collected from several prospective, phase III clinical studies and an observational registry. The phase III program (N = 412) included four multicenter studies: a 12-week, randomized, double-blind study and three open-label studies extending ≥12 months. GLORIA (N = 412) included four multicenter studies: a 12-week, randomized, double-blind study and three open-label studies extending ≥12 months. GLORIA (. RESULTS: A total of 72 of 412 (17.5%) patients required dosages ≥2000 mg/day LCIG in the phase III program and 47 of 375 (12.5%) patients in GLORIA. Baseline demographics and disease severity were similar between dosage groups with more men in the high-dosage group. Compared with the <2000 mg/day dosage group, patients requiring ≥2000 mg/day LCIG had higher rates of AEs/ADRs including polyneuropathy; improvements in "Off" time and discontinuations due to AEs were similar between dosage groups and lower for discontinuations due to ADRs reported in GLORIA. CONCLUSIONS: Patients who require ≥2000 mg/day LCIG exhibited a safety profile comparable to the established safety/tolerability of LCIG with similar clinical improvements. Higher AEs were noted but within what is accepted for LCIG. Continuous administration of LCIG is beneficial to advanced PD patients who require very high doses of levodopa.

Systematic evaluation of levodopa-carbidopa intestinal gel patient-responder characteristics.

Levodopa-carbidopa intestinal gel (LCIG, carbidopa-levodopa enteral suspension in the United States) is a treatment option for advanced Parkinson's disease (PD) patients with motor fluctuations. The objective of this investigation was to identify the baseline characteristics predictive of treatment response, measured by improvement in motor symptom severity, in advanced PD patients treated with LCIG during a 54-week, open-label phase 3 study. Patients with ≥1 h improvement from baseline in "Off" time were categorized as "Responders"; whereas those with <1 h improvement, any worsening, or no post-baseline assessment were "Non-Responders". A subgroup of Responders with ≥3 h improvement in "Off" time was also examined; this subgroup was identified as "Robust Responders". Baseline demographics and disease characteristics were analyzed and their predictive relationship to change from baseline in normalized "Off" time was assessed. Out of the 324 patients included in the analysis, 272 (84.0%) were categorized as Responders and 52 (16.0%) were Non-Responders. A majority of patients (65.7%) had ≥3 h improvement in "Off" time. In general, baseline characteristics were similar between Non-responders, Responders, and the subgroup of Robust Responders. A conditional tree-structured regression analysis identified baseline "Off" time as the only factor that had significant effect on Responder and Robust Responder status. The safety profile of LCIG was similar between patient groups. Overall, this analysis showed that 84% of LCIG-treated advanced PD patients had ≥1 h improvement in "Off" time and the number-needed-to-treat to observe one patient responder was 1.19 patients. Notably, Responders and Robust Responders to LCIG were observed across the range of baseline demographics and clinical characteristics examined.

Association of metabolic syndrome and change in Unified Parkinson's Disease Rating Scale scores.

OBJECTIVE: To explore the association between metabolic syndrome and the Unified Parkinson's Disease Rating Scale (UPDRS) scores and, secondarily, the Symbol Digit Modalities Test (SDMT). METHODS: This is a secondary analysis of data from 1,022 of 1,741 participants of the National Institute of Neurological Disorders and Stroke Exploratory Clinical Trials in Parkinson Disease Long-Term Study 1, a randomized, placebo-controlled trial of creatine. Participants were categorized as having or not having metabolic syndrome on the basis of modified criteria from the National Cholesterol Education Program Adult Treatment Panel III. Those who had the same metabolic syndrome status at consecutive annual visits were included. The change in UPDRS and SDMT scores from randomization to 3 years was compared in participants with and without metabolic syndrome. RESULTS: Participants with metabolic syndrome (n = 396) compared to those without (n = 626) were older (mean [SD] 63.9 [8.1] vs 59.9 [9.4] years; p < 0.0001), were more likely to be male (75.3% vs 57.0%; p < 0.0001), and had a higher mean uric acid level (men 5.7 [1.3] vs 5.3 [1.1] mg/dL, women 4.9 [1.3] vs 3.9 [0.9] mg/dL, p < 0.0001). Participants with metabolic syndrome experienced an additional 0.6- (0.2) unit annual increase in total UPDRS (p = 0.02) and 0.5- (0.2) unit increase in motor UPDRS (p = 0.01) scores compared with participants without metabolic syndrome. There was no difference in the change in SDMT scores. CONCLUSIONS: Persons with Parkinson disease meeting modified criteria for metabolic syndrome experienced a greater increase in total UPDRS scores over time, mainly as a result of increases in motor scores, compared to those who did not. Further studies are needed to confirm this finding. CLINICALTRIALSGOV IDENTIFIER: NCT00449865.

Longer Duration of MAO-B Inhibitor Exposure is Associated with Less Clinical Decline in Parkinson's Disease: An Analysis of NET-PD LS1.

BACKGROUND: Monoamine oxidase type B (MAO-B) inhibitors exhibit neuroprotective effects in preclinical models of PD but clinical trials have failed to convincingly demonstrate disease modifying benefits in PD patients. OBJECTIVE: To perform a secondary analysis of NET-PD LS1 to determine if longer duration of MAO-B inhibitor exposure was associated with less clinical decline. METHODS: The primary outcome measure was the Global Outcome (GO), comprised of 5 measures: change from baseline in the Schwab and England (ADL) scale, the 39-item Parkinson's Disease Questionnaire (PDQ-39), the UPDRS Ambulatory Capacity Scale, the Symbol Digit Modalities Test, and the most recent Modified Rankin Scale. A linear mixed model was used to explore the association between the cumulative duration of MAO-B inhibitor exposure and the GO, adjusting for necessary factors and confounders. Associations between MAO-B inhibitor exposure and each of the five GO components were then studied individually. RESULTS: 1616 participants comprised the analytic sample. Mean observation was 4.1 (SD = 1.4) years, and 784 (48.5%) participants received an MAO-B inhibitor. The regression coefficient of cumulative duration of MAO-B inhibitor exposure (in years) on the GO was - 0.0064 (SE = 0.002, p = 0.001). Significant associations between duration of MAO-B inhibitor exposure and less progression were observed for ADL (p < 0.001), Ambulatory Capacity (p < 0.001), and the Rankin (p = 0.002). CONCLUSIONS: Our analysis identified a significant association between longer duration of MAO-B inhibitor exposure and less clinical decline. These findings support the possibility that MAO-B inhibitors slow clinical disease progression and suggest that a definitive prospective trial should be considered.

Factors associated with falling in early, treated Parkinson's disease: The NET-PD LS1 cohort.

BACKGROUND: Recognizing the factors associated with falling in Parkinson's disease (PD) would improve identification of at-risk individuals. OBJECTIVE: To examine frequency of falling and baseline characteristics associated with falling in PD using the National Institute of Neurological Disorders and Stroke (NINDS) Exploratory Trials in PD Long-term Study-1 (NET-PD LS-1) dataset. METHODS: The LS-1 database included 1741 early treated PD subjects (median 4year follow-up). Baseline characteristics were tested for a univariate association with post-baseline falling during the trial. Significant variables were included in a multivariable logistic regression model. A separate analysis using a negative binomial model investigated baseline factors on fall rate. RESULTS: 728 subjects (42%) fell during the trial, including at baseline. A baseline history of falls was the factor most associated with post-baseline falling. Men had lower odds of post-baseline falling compared to women, but for men, the probability of a post-baseline fall increased with age such that after age 70, men and women had similar odds of falling. Other baseline factors associated with a post-baseline fall and increased fall rate included the Unified PD Rating Scale (UPDRS) Activities of Daily Living (ADL) score, total functional capacity (TFC), baseline ambulatory capacity score and dopamine agonist monotherapy. CONCLUSION: Falls are common in early treated PD. The biggest risk factor for falls in PD remains a history of falling. Measures of functional ability (UPDRS ADL, TFC) and ambulatory capacity are novel clinical risk factors needing further study. A significant age by sex interaction may help to explain why age has been an inconsistent risk factor for falls in PD.

Parkinsonism in Patients With Chronic Hepatitis C Treated With Interferons: Case Reports and Review of the Literature.

Interferons are a set of cytokines that activate antiviral responses by the body's immune cells and have been a mainstay of treatment of hepatitis C. Well-known neuropsychiatric effects of interferons include depression, irritability, and impaired concentration. A condition reported rarely in association with this treatment is parkinsonism. We report 2 patients who developed parkinsonism in conjunction with treatment of hepatitis C with alpha interferons. The first is a 51-year-old man who developed intermittent rest and postural tremor during treatment with pegylated interferon alpha ribavirin, and amantadine, with resolution of the symptoms after completing a 36-week course. Similar tremor recurred 3 years later with progressive parkinsonism, compatible with Parkinson disease (PD). The second patient is a 71-year-old man who developed postural tremor 8 weeks into a regimen of consensus interferon. Tremor resolved at completion of 48 weeks of interferon. Pegylated interferon alpha and ribavirin were started 2 years later because of lack of sustained virologic response. At 24 weeks of treatment, postural tremor returned along with features and a progressive course compatible with PD. Thus, both patients presented here developed (rest and/or postural) tremor during interferon therapy followed by delayed onset of parkinsonism. We identified 10 other cases in the literature of parkinsonism/PD associated with interferon administration. This report reviews the clinical presentation and potential pathophysiological mechanisms and recommends that physicians who prescribe interferon be vigilant for symptoms of PD in their patients.

Choice of dopaminergic therapy among early, mild Parkinson disease subjects in North America.

The choice of dopaminergic therapy in early Parkinson disease (PD) is an important clinical decision, yet factors influencing this decision have not been extensively studied. We sought to investigate the factors that may be associated with the choice of dopaminergic therapy at the NINDS Exploratory Trials in PD (NET-PD) Long-Term Study-1 (LS1). NET-PD LS1 was a clinical trial of creatine versus placebo in participants with early, mild PD on stable doses of dopaminergic therapy. Baseline data from 1616 out of the 1741 participants were evaluated using univariable and multivariable logistic or generalized logit regression analyses for available factors associated with the choice of dopaminergic therapy. The dopaminergic therapy choice was determined as: (i) therapy that subjects recalled taking 180days before the study; (ii) therapy at baseline; and (iii) the longest duration of therapy reported by participants. Younger age, higher education level, longer length of time since PD diagnosis and use of an adjunctive, non-dopaminergic or monoamine oxidase inhibitor medication were associated with more frequent use of dopamine agonist compared to levodopa or combination therapy.

Domains and correlates of clinical balance impairment associated with Huntington's disease.

This study sought to (a) determine the domains of clinical balance impairments associated with Huntington's disease (HD), and (b) evaluate associations between balance test scores and other disease-related impairments. Eighteen subjects with genetically definite HD and 17 age-matched control subjects were evaluated on the Mini-BESTest for their clinical balance impairments as well as the Unified HD Rating Scale (UHDRS) motor and total functional capacity scales, Activity-Specific Balance Confidence (ABC) Scale-short form, Montreal Cognitive Assessment (MoCA), and Symbol Digit Modalities Test (SDMT). Results showed that subjects with HD exhibited significantly lower total Mini-BESTest scores than subjects without HD (mean (95% CI)=76 (64-87)% with HD, 98 (96-99)% without HD; p=0.0011). Mini-BESTest item scores were significantly lower for subjects with HD on one-leg stance, postural responses, standing with eyes closed on foam, and dual-task timed up-and-go. Mini-BESTest scores significantly correlated with UHDRS motor (r(2)=0.68; p=0.00003) and total functional capacity (r(2)=0.75; p=0.000006) scores as well as with scores on the ABC short form (r(2)=0.45; p=0.0024), SDMT (r(2)=0.42; p=0.0036), and MoCA (r(2)=0.23; p=0.046) assessments. This study, therefore, demonstrates that balance impairments associated with HD span domains of anticipatory postural adjustments, postural responses, stance in challenging sensory conditions, and gait. Although preliminary, clinical balance impairment appears to be an efficient proxy evaluation of multiple HD-related factors due to associations with functional capacity, other motor impairments, balance confidence, and cognitive abilities.

Validation of an ambulatory capacity measure in Parkinson disease: a construct derived from the Unified Parkinson's Disease Rating Scale.

BACKGROUND: A construct calculated as the sum of items 13-15, 29, 30 of the Unified Parkinson's Disease Rating Scale (UPDRS) has been used as an "Ambulatory Capacity Measure" (ACM) in Parkinson disease (PD). Its construct validity has never been examined. A similar construct, consisting of the mean value of the same UPDRS items has been used under the acronym PIGD as a measure of postural instability and gait disorder in PD. OBJECTIVE: To examine the construct validity of the ACM and PIGD in PD. METHODS: We analyzed data in an existing database of 340 PD patients, Hoehn and Yahr stages (HYS) 1-5 who participated in a study of falls. Number of falls (NOF) was recorded over 4 weeks, and UPDRS (mental, ADL, and motor subscales), HYS, Activities Based Confidence Scale (ABC), Freezing of Gait Questionnaire (FOG), Five Times Sit-to-Stand (FTSS), Timed Up-and Go (TUG), Gait Velocity (GV), and Berg Balance Scale (BBS) evaluations were performed. Internal consistency was assessed by Cronbach's alpha. Construct validity was assessed through correlations of the ACM and PIGD to these measures and to their summed-ranks. A coefficient of determination was calculated through linear regression. RESULTS: Mean age was 71.4, mean age at diagnosis 61.4 years; 46% were women; mean UPDRS subscale scores were: Mental 3.7; ADL 15.7; motor: 27.1; mean ACM was 6.51, and mean PIGD 1.30. Cronbach's alpha was 0.78 for both ACM and PIGD. Spearman correlation coefficients between the ACM/PIGD and ABC, FOG, TUG, GV and BBS were 0.69, 0.72, 0.67, 0.58, and 0.70 respectively. Correlation between the ACM/PIGD and summed-ranks of HYS, NOF, ABC, FOG, FTSS, TUG, GV and BBS was high (Spearman r = 0.823, p < 0.0001); 68% of the variability in the summed-ranks was explained by ACM/PIGD. CONCLUSION: The ACM and the PIGD are valid global measures and accurately reflect the combined effects of the various components of ambulatory capacity in PD patients with HY stages 1-4.

Parkinson's disease severity and use of dopaminergic medications.

BACKGROUND: The effects of dopaminergic therapy in parkinson's disease (PD) can vary depending on the class of medication selected. OBJECTIVE: The aim of this post hoc study was to determine if the class of dopaminergic therapy correlated with disease severity in persons with early, treated PD. METHODS: A non-parametric global statistical test (GST) was used to assess the status of participants treated with dopamine agonist (DA) monotherapy, levodopa (LD) monotherapy or combined LD and DA therapy on multiple PD outcomes encompassing motor, cognitive, psychiatric and autonomic function, as well as disability and quality of life. RESULTS: The outcomes measured at the beginning of the study showed lower disease burden for participants on initial DA monotherapy compared to those taking combined LD and DA therapy after controlling for age, education, taking cog-meds and amantadine. CONCLUSION: This observation suggests that clinicians treating early PD patients favor combined LD and DA therapy in patients with more disabling features over DA monotherapy. As such, studies of PD progression in treated PD patients may be affected by the class of symptomatic dopaminergic therapy.