Predictors of Cognitive Change in Parkinson Disease: A 2-year Follow-up Study

BACKGROUND

Mild cognitive impairment is common in Parkinson disease (PD-MCI). However, instability in this clinical diagnosis and variability in rates of progression to dementia raises questions regarding its utility for longitudinal tracking and prediction of cognitive change in PD. We examined baseline neuropsychological test and cognitive diagnosis predictors of cognitive change in PD.

METHODS

Persons with PD, without dementia PD (N=138) underwent comprehensive neuropsychological assessment at baseline and were followed up to 2 years. Level II Movement Disorder Society criteria for PD-MCI and PD dementia (PDD) were applied annually. Composite global and domain cognitive z -scores were calculated based on a 10-test neuropsychological battery.

RESULTS

Baseline diagnosis of PD-MCI was not associated with a change in global cognitive z -scores. Lower baseline attention and higher executive domain z -scores were associated with greater global cognitive z -score worsening regardless of cognitive diagnosis. Worse baseline domain z -scores in the attention and language domains were associated with progression to MCI or PDD, whereas higher baseline scores in all cognitive domains except executive function were associated with clinical and psychometric reversion to "normal" cognition.

CONCLUSIONS

Lower scores on cognitive tests of attention were predictive of worse global cognition over 2 years of follow-up in PD, and lower baseline attention and language scores were associated with progression to MCI or PDD. However, PD-MCI diagnosis per se was not predictive of cognitive decline over 2 years. The association between higher executive domain z -scores and greater global cognitive worsening is probably a spurious result.

Comparative Effectiveness of Device-Aided Therapies on Quality of Life and Off-Time in Advanced Parkinson's Disease: A Systematic Review and Bayesian Network Meta-analysis

INTRODUCTION

Research comparing levodopa/carbidopa intestinal gel (LCIG), deep brain stimulation (DBS), and continuous subcutaneous apomorphine infusion (CSAI) for advanced Parkinson's disease (PD) is lacking. This network meta-analysis (NMA) assessed the comparative effectiveness of LCIG, DBS, CSAI and best medical therapy (BMT) in reducing off-time and improving quality of life (QoL) in patients with advanced PD.

METHODS

A systematic literature review was conducted for randomized controlled trials (RCTs), observational and interventional studies from January 2003 to September 2019. Data extracted at baseline and 6 months were off-time, as reported by diary or Unified Parkinson's Disease Rating Scale Part IV item 39, and QoL, as reported by Parkinson's Disease Questionnaire (PDQ-39/PDQ-8). Bayesian NMA was performed to estimate pooled treatment effect sizes and to rank treatments in order of effectiveness.

RESULTS

A total of 22 studies fulfilled the inclusion criteria (n = 2063 patients): four RCTs, and 16 single-armed, one 2-armed and one 3-armed prospective studies. Baseline mean age was between 55.5-70.9 years, duration of PD was 9.1-15.3 years, off-time ranged from 5.4 to 8.7 h/day in 9 studies, and PDQ scores ranged from 28.8 to 67.0 in 19 studies. Levodopa/carbidopa intestinal gel and DBS demonstrated significantly greater improvement in off-time and QoL at 6 months compared with CSAI and BMT (p < 0.05). There was no significant difference in the effects of LCIG and DBS, but DBS was ranked first for reduction in off-time, and LCIG was ranked first for improvement in QoL.

CONCLUSIONS

This NMA found that LCIG and DBS were associated with superior improvement in off-time and PD-related QoL compared with CSAI and BMT at 6 months after treatment initiation. This comparative effectiveness research may assist providers, patients, and caregivers in the selection of the optimal device-aided therapy.

Effects of Levodopa-Carbidopa Intestinal Gel on Dyskinesia and Non-Motor Symptoms Including Sleep: Results from a Meta-Analysis with 24-Month Follow-Up

BACKGROUND

In advanced Parkinson's disease (PD), dyskinesias and non-motor symptoms such as sleep dysfunction can significantly impair quality of life, and high-quality management is an unmet need.

OBJECTIVE

To analyze changes in dyskinesia and non-motor symptoms (including sleep) among studies with levodopa-carbidopa intestinal gel (LCIG) in patients with advanced PD.

METHODS

A comprehensive literature review identified relevant studies examining LCIG efficacy. Outcomes of interest were dyskinesia (UDysRS, UPDRS IV item 32), overall non-motor symptoms (NMSS), mentation/behavior/mood (UPDRS I), and sleep/daytime sleepiness (PDSS-2, ESS). The pooled mean (95% confidence interval) change from baseline per outcome was estimated for each 3-month interval with sufficient data (i.e., reported by≥3 studies) up to 24 months using a random-effects model.

RESULTS

Seventeen open-label studies evaluating 1243 patients with advanced PD were included. All outcomes of interest with sufficient data for meta-analysis showed statistically significant improvement within 6 months of starting LCIG. There were statistically significant improvements in dyskinesia duration as measured by UPDRS IV item 32 at 6 months (-1.10 [-1.69, -0.51] h/day) and 12 months (-1.35 [-2.07, -0.62] h/day). There were statistically and clinically significant improvements in non-motor symptoms as measured by NMSS scores at 3 months (-28.71 [-40.26, -17.15] points). Significant reduction of NMSS burden was maintained through 24 months (-17.61 [-21.52, -13.70] points). UPDRS I scores significantly improved at 3 months (-0.39 [-0.55, -0.22] points). Clinically significant improvements in PDSS-2 and ESS scores were observed at 6 and 12 months in individual studies.

CONCLUSION

Patients with advanced PD receiving LCIG showed significant sustained improvements in the burden of dyskinesia and non-motor symptoms up to 24 months after initiation.

The Social Value of Improvement in Activities of Daily Living among the Advanced Parkinson's Disease Population

OBJECTIVES

Quantify the value of functional status (FS) improvements consistent in magnitude with improvements due to levodopa-carbidopa intestinal gel (LCIG) treatment, among the advanced Parkinson's disease (APD) population.

METHODS

The Health Economic Medical Innovation Simulation (THEMIS), a microsimulation that estimates future health conditions and medical spending, was used to quantify the health and cost burden of disability among the APD population, and the value of quality-adjusted life-years gained from FS improvement due to LCIG treatment compared to standard of care (SoC). A US-representative Parkinson's disease (PD)-comparable cohort was constructed in THEMIS based on observed PD patient characteristics in a nationally representative dataset. APD was defined from the literature and clinical expert input. The PD and APD cohorts were followed from 2010 over their remaining lifetimes. All individuals were ages 65 and over at the start of the simulation. To estimate the value of FS improvement due to LCIG treatment, decreases in activities of daily living (ADL) limitations caused by LCIG treatment were calculated using data from a randomized, controlled, double-blind, double-dummy clinical trial and applied to the APD population in THEMIS.

RESULTS

Total burden of disability associated with APD was $17.7 billion (B). From clinical trial data, LCIG treatment versus SoC lowers the odds of difficulties in walking, dressing, and bathing by 76%, 42% and 39%, respectively. Among the APD population, these reductions generated $2.6B in value to patients and cost savings to payers. The added value was 15% of the burden of disability associated with APD and offsets 15% of the cost of LCIG treatment.

CONCLUSIONS

FS improvements, consistent with improvements due to LCIG treatment, in the APD population created health benefits and reduced healthcare costs in the US.

Motor Unit Discharge Variability Is Increased in Mild-To-Moderate Parkinson's Disease

Individuals with Parkinson's disease (PD) demonstrate deficits in muscle activation such as decreased amplitude and inappropriate bursting. There is evidence that some of these disturbances are more pronounced in extensor vs. flexor muscles. Surface EMG has been used widely to quantify muscle activation deficits in PD, but analysis of discharge of the underlying motor units may provide greater insight and be more sensitive to changes early in the disease. Of the few studies that have examined motor unit discharge in PD, the majority were conducted in the first dorsal interosseous, and no studies have measured motor units from extensor and flexor muscles within the same cohort. The objective of this study was to characterize the firing behavior of single motor units in the elbow flexor and extensor muscles during isometric contractions in people with mild-to-moderate PD. Ten individuals with PD (off-medication) and nine healthy controls were tested. Motor unit spike times were recorded via intramuscular EMG from the biceps and triceps brachii muscles during 30-s isometric contractions at 10% maximum voluntary elbow flexion and elbow extension torque, respectively. We selected variables of mean motor unit discharge rate, discharge variability, and torque variability to evaluate motor abnormalities in the PD group. The effects of group, muscle, and group-by-muscle on each variable were determined using separate linear mixed models. Discharge rate and torque variability were not different between groups, but discharge variability was significantly higher in the PD group for both muscles combined (p < 0.0001). We also evaluated the asymmetry in these motor variables between the triceps and biceps for each individual participant with PD to evaluate whether there was an association with disease severity. The difference in torque variability between elbow flexion and extension was significantly correlated with both the Hoehn and Yahr scale (rho = 0.71) and UPDRS (rho = 0.62). Our findings demonstrate that variability in motor output, rather than decreased discharge rates, may contribute to motor dysfunction in people with mild-to-moderate PD. Our findings provide insight into altered neural control of movement in PD and demonstrate the importance of measuring from multiple muscles within the same cohort.

The effect of functional status impairment on nursing home admission risk among patients with advanced Parkinson's disease

Aims: To estimate the relationship between functional status (FS) impairment and nursing home admission (NHA) risk in Parkinson's disease (PD) patients, and quantify the effect of advanced PD (APD) treatment on NHA risk relative to standard of care (SoC).Materials and methods: PD patients were identified in the Medicare Current Beneficiary Survey (MCBS) (1992-2010). A working definition based on the literature and clinical expert input determined APD status. A logit model estimated the relationship between FS impairment and NHA risk. The effect of levodopa-carbidopa intestinal gel (LCIG) on NHA risk relative to SoC was simulated using clinical trial data (control: optimized oral levodopa-carbidopa IR, ClinicalTrials.gov NCT00660387 and NCT0357994).Results: Non-advanced PD and APD significantly increased NHA risk when controlling for demographics (p < 0.01). APD status was no longer significant after controlling for FS limitations, implying that FS limitations explain the increased NHA risk in APD patients. Reduced impairment in FS in patients with APD treated with LCIG reduced risk of NHA by 13.5% relative to SoC.Limitations: This study applies clinical trial results to real-world data. LCIG treatment might have a different effect on NHA risk for the nationally representative population than the effect measured in the trial. Both data sources employ different instruments to measure FS, instrument wording and study follow-up differed, which might bias our estimates. Finally, there lacks consensus on a definition of APD. The prevalence of APD in this study is high, perhaps due to the specific definition used.Conclusions: Patients with APD experience a higher risk in NHA than those with non-advanced disease. This increased risk in NHA in patients with APD is explained by greater limitations in FS. The relative reduction in risk of NHA for the APD population treated with LCIG is quantitatively similar to doubling Medicaid home care services.

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.

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Advanced Parkinson's disease (PD) often requires a large number of medications

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Levodopa-carbidopa intestinal gel (LCIG) is administered continuously

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LCIG monotherapy vs. polytherapy was assessed in six phase 3/3b studies

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LCIG monotherapy and polytherapy had similar efficacy and safety profiles

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LCIG monotherapy may provide a more simplified treatment option for advanced PD

Voluntary Saccade Training Protocol in Persons With Parkinson's Disease and Healthy Adults

Background: Voluntary saccade function gradually decreases during both the progression of Parkinson's disease (PD) and neurologically healthy adult aging. Voluntary saccades display decreased length and increased saccade latency, duration, and the number of compensatory saccades in aging and PD. Saccades serve as the key eye movement for maintaining salient features of the visual environment on the high visual acuity fovea of the retina. Abnormal saccade behavior has been associated with freezing of gait in PD. We have not identified any studies that have investigated improvement in voluntary saccade function using voluntary saccade training. Objective: We report an experimental protocol that tests a training paradigm following the principle of specificity to improve voluntary saccade velocity and amplitude, while decreasing latency and the number of compensatory saccades. Methods: Persons with PD (n = 22) and persons with no known neurological disorders (n = 22) between the ages of 40 and 65 years will be recruited. In a randomized-block study design, all participants will perform voluntary saccades to targets in eight cardinal and intercardinal directions. In each of the eight sessions during the four-week intervention period, participants will train at three target amplitudes. Participants will perform 40 trials for each amplitude block, consisting of five randomly presented repetitions for each direction. Voluntary and reflexive saccades will be recorded pre- and post-intervention, along with clinical mobility assessment using the Movement Disorder Society Unified Parkinson's Disease Rating Scale. Mobility scores, the amplitude, latency, and duration of the first saccade, and the number of saccades to reach the fixation target will be analyzed using an ANOVA of mixed effects. Discussion: This protocol holds promise as a potential method to improve voluntary saccade function in persons with PD. Should persons with PD not improve on any outcome following the intervention, this lack of response may support the use of saccade assessment as a response biomarker for the diagnosis of PD. Trial Registration: This protocol was retrospectively registered at ISRCTN (ISRCTN.com) since July 25, 2018. The first participant was recruited March 12, 2016. The protocol identifier is 17784042. Descriptive Title: A two-arm, pre/post-protocol to compare the effects of a four-week voluntary saccade training intervention in persons with Parkinson's disease and healthy adults aged forty years or older.

Responsiveness to Change of the Montreal Cognitive Assessment, Mini-Mental State Examination, and SCOPA-Cog in Non-Demented Patients with Parkinson's Disease

BACKGROUND

Clinical monitoring of patients with Parkinson's disease (PD) for cognitive decline is an important element of care. The Montreal Cognitive Assessment (MoCA) has been proposed to be a sensitive tool for assessing cognitive impairment in PD. The aim of our study was to compare the responsiveness of the MoCA to decline in cognition to the responsiveness of the Mini Mental State Examination (MMSE) and the Scales for Outcomes of Parkinson's disease-cognition (SCOPA-Cog).

METHODS

PD patients without dementia were enrolled at 6 North American movement disorders centers between 2008 and 2011. Participants received annual evaluations including the MoCA, MMSE, and SCOPA-Cog followed by formal neuropsychological testing. The gold standard for change in cognition was defined as the change on the neuropsychological test scores over the annual assessments. The Reliable Change Method was used to provide an estimate of the probability that a given difference score would be obtained by chance. The sensitivity of the MoCA, MMSE, and SCOPA-Cog to change was quantified using receiver operating characteristics (ROC) curves.

RESULTS

One hundred seventeen patients were included in the analysis. Participants were followed at mean intervals of 11 ± 2 months for a median of 2 (maximum 5) visits. According to the reliable change index, 56 intervals of cognitive testing showed a decline in global cognition. ROC analysis of change in MoCA, MMSE, and SCOPA-Cog global scores compared to gold standard testing found an area under the curve (AUC) of 0.55 (95% CI 0.48-0.62), 0.56 (0.48-0.63), and 0.63 (0.55-0.70) respectively. There were no significant differences in the AUCs across the tests. The sensitivity of the MoCA, MMSE, and SCOPA-Cog to change at various thresholds for decline in scores reached a maximum of 71% for a cut-off of 1 point change on the SCOPA-Cog.

CONCLUSION

Using neuropsychological testing as a gold standard comparator, the performance of the MoCA, MMSE, and SCOPA-Cog for detecting decline in non-demented PD patients over a 1-year interval is poor. This has implications for clinical practice; stable scores may not be taken as reassurance of the absence of cognitive decline.

Neurology Clerkship: Predictors of Objective Structured Clinical Examination and Shelf Performance

BACKGROUND

We sought to determine whether the following factors are associated with stronger performance on the medical school neurology clerkship: (1) structure of the outpatient rotation (working with a single general neurologist or multiple subspecialists), (2) dedicated shelf exam preparation, and (3) clerkships completed prior to neurology rotation.

METHODS

A total of 439 Feinberg medical students between 2014 and 2016 were analyzed based on the 3 variables of interest listed above. Student performance was evaluated using the National Board of Medical Examiner shelf exam and Objective Structured Clinical Examination/standardized evaluation scores. Univariate and multivariate analyses were conducted.

RESULTS

The format of the 2-week outpatient rotation did not significantly affect shelf examination (P = .59), or standardized evaluation (P = .34) scores. Taking a shelf pre-test correlated with overall higher standardized evaluation scores (P < .01), and higher shelf examination scores (P < .01). No individual clerkship correlated with better performance; however, the total number of core clerkships was associated with higher shelf examination scores (P = .007). Each additional core clerkship taken prior to neurology was associated with 0.72 points greater shelf examination score.

CONCLUSIONS

Greater attending continuity did not appear to be associated with stronger performance perhaps due to a difference in types of cases observed. Students who took a practice shelf exam did better on both their shelf exam and standardized evaluation, suggesting that acquisition of knowledge translates to a better clinical performance. No individual clerkship offers an advantage, but rather it is the total number of clerkships that is correlated with stronger performance.

Long-term effect of low frequency stimulation of STN on dysphagia, freezing of gait and other motor symptoms in PD

OBJECTIVE

To evaluate the long-term effect of 60 Hz stimulation of the subthalamic nucleus (STN) on dysphagia, freezing of gait (FOG) and other motor symptoms in patients with Parkinson's disease (PD) who have FOG at the usual 130 Hz stimulation.

METHODS

This is a prospective, sequence randomised, crossover, double-blind study. PD patients with medication refractory FOG at 130 Hz stimulation of the STN were randomised to the sequences of 130 Hz, 60 Hz or deep brain stimulation off to assess swallowing function (videofluoroscopic evaluation and swallowing questionnaire), FOG severity (stand-walk-sit test and FOG questionnaire) and motor function (Unified PD Rating Scale, Part III motor examination (UPDRS-III)) at initial visit (V1) and follow-up visit (V2, after being on 60 Hz stimulation for an average of 14.5 months), in their usual medications on state. The frequency of aspiration events, perceived swallowing difficulty and FOG severity at 60 Hz compared with 130 Hz stimulation at V2, and their corresponding changes at V2 compared with V1 at 60 Hz were set as primary outcomes, with similar comparisons in UPDRS-III and its subscores as secondary outcomes.

RESULTS

All 11 enrolled participants completed V1 and 10 completed V2. We found the benefits of 60 Hz stimulation compared with 130 Hz in reducing aspiration frequency, perceived swallowing difficulty, FOG severity, bradykinesia and overall axial and motor symptoms at V1 and persistent benefits on all of them except dysphagia at V2, with overall decreasing efficacy when comparing V2 to V1.

CONCLUSIONS

The 60 Hz stimulation, when compared with 130 Hz, has long-term benefits on reducing FOG, bradykinesia and overall axial and motor symptoms except dysphagia, although the overall benefits decrease with long-term use.

CLINICAL TRIAL REGISTRATION

NCT02549859; Pre-results.

Implementing Levodopa-Carbidopa Intestinal Gel for Parkinson Disease: Insights from US Practitioners

Background

Levodopa‐carbidopa intestinal gel (LCIG, designated in the United States as carbidopa‐levodopa enteral suspension, CLES) was approved in the United States in 2015 for the treatment of refractory motor fluctuations in individuals with Parkinson disease (PD). Many neurologists in the United States have not had personal experience with implementation and management of the unique delivery system for this treatment.

Methods and Findings

This educational review was developed to provide practitioners with an understanding of LCIG use from the clinician's point of view. Practical recommendations for the use of LCIG from the early planning stages through long‐term patient management were compiled from the published literature, regulatory guidance, and clinical experience. Among the topics reviewed were: assembling a multidisciplinary treatment team, identifying treatment candidates, patient/care partner education, procedural considerations, post‐procedural care, LCIG initiation and titration, troubleshooting issues, and ongoing monitoring. For most of these steps, a considerable amount of individualization is possible, which allows clinicians to tailor protocols based on the needs of their teams, the healthcare system, and the patient and care partner. Although clinical practices are heterogeneous, themes of early planning, ongoing education, and a team‐based approach to management are universal.

Conclusions

By using established protocols and insights gleaned from experienced practitioners, clinicians who are unfamiliar with LCIG can more feasibly incorporate this treatment option into their armamentarium for treating PD motor fluctuations.

Clustering of motor and nonmotor traits in leucine-rich repeat kinase 2 G2019S Parkinson's disease nonparkinsonian relatives: A multicenter family study

OBJECTIVES

The objective of this study was to determine phenotypic features that differentiate nonparkinsonian first-degree relatives of PD leucine-rich repeat kinase 2 (LRRK2) G2019S multiplex families, regardless of carrier status, from healthy controls because nonparkinsonian individuals in multiplex families seem to share a propensity to present neurological features.

METHODS

We included nonparkinsonian first-degree relatives of LRRK2 G2019S familial PD cases and unrelated healthy controls participating in established multiplex family LRRK2 cohorts. Study participants underwent neurologic assessment including cognitive screening, olfaction testing, and questionnaires for daytime sleepiness, depression, and anxiety. We used a multiple logistic regression model with backward variable selection, validated with bootstrap resampling, to establish the best combination of motor and nonmotor features that differentiates nonparkinsonian first-degree relatives of LRRK2 G2019S familial PD cases from unrelated healthy controls.

RESULTS

We included 142 nonparkinsonian family members and 172 unrelated healthy controls. The combination of past or current symptoms of anxiety (adjusted odds ratio, 4.16; 95% confidence interval, 2.01-8.63), less daytime sleepiness (adjusted odds ratio [1 unit], 0.90; 95% confidence interval, 0.83-0.97], and worse motor UPDRS score (adjusted odds ratio [1 unit], 1.4; 95% confidence interval, 1.20-1.67) distinguished nonparkinsonian family members, regardless of LRRK2 G2019S mutation status, from unrelated healthy controls. The model accuracy was good (area under the curve = 79.3%).

CONCLUSIONS

A set of motor and nonmotor features distinguishes first-degree relatives of LRRK2 G2019S probands, regardless of mutation status, from unrelated healthy controls. Environmental or non-LRRK2 genetic factors in LRRK2-associated PD may influence penetrance of the LRRK2 G2019S mutation. The relationship of these features to actual PD risk requires longitudinal observation of LRRK2 familial PD cohorts. © 2018 International Parkinson and Movement Disorder Society.

National randomized controlled trial of virtual house calls for Parkinson disease

OBJECTIVE

To determine whether providing remote neurologic care into the homes of people with Parkinson disease (PD) is feasible, beneficial, and valuable.

METHODS

In a 1-year randomized controlled trial, we compared usual care to usual care supplemented by 4 virtual visits via video conferencing from a remote specialist into patients' homes. Primary outcome measures were feasibility, as measured by the proportion who completed at least one virtual visit and the proportion of virtual visits completed on time; and efficacy, as measured by the change in the Parkinson's Disease Questionnaire-39, a quality of life scale. Secondary outcomes included quality of care, caregiver burden, and time and travel savings.

RESULTS

A total of 927 individuals indicated interest, 210 were enrolled, and 195 were randomized. Participants had recently seen a specialist (73%) and were largely college-educated (73%) and white (96%). Ninety-five (98% of the intervention group) completed at least one virtual visit, and 91% of 388 virtual visits were completed. Quality of life did not improve in those receiving virtual house calls (0.3 points worse on a 100-point scale; 95% confidence interval [CI] -2.0 to 2.7 points; p = 0.78) nor did quality of care or caregiver burden. Each virtual house call saved patients a median of 88 minutes (95% CI 70-120; p < 0.0001) and 38 miles per visit (95% CI 36-56; p < 0.0001).

CONCLUSIONS

Providing remote neurologic care directly into the homes of people with PD was feasible and was neither more nor less efficacious than usual in-person care. Virtual house calls generated great interest and provided substantial convenience.

CLINICALTRIALSGOV IDENTIFIER

NCT02038959.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that for patients with PD, virtual house calls from a neurologist are feasible and do not significantly change quality of life compared to in-person visits. The study is rated Class III because it was not possible to mask patients to visit type.

National Randomized Controlled Trial of Virtual House Calls for People with Parkinson's Disease: Interest and Barriers

BACKGROUND

Delivering specialty care remotely directly into people's homes can enhance access for and improve the healthcare of individuals with chronic conditions. However, evidence supporting this approach is limited.

MATERIALS AND METHODS

Connect.Parkinson is a randomized comparative effectiveness study that compares usual care of individuals with Parkinson's disease in the community with usual care augmented by virtual house calls with a Parkinson's disease specialist from 1 of 18 centers nationally. Individuals in the intervention arm receive four virtual visits from a Parkinson's disease specialist over 1 year via secure, Web-based videoconferencing directly into their homes. All study activities, including recruitment, enrollment, and assessments, are conducted remotely. Here we report on interest, feasibility, and barriers to enrollment in this ongoing study.

RESULTS

During recruitment, 11,734 individuals visited the study's Web site, and 927 unique individuals submitted electronic interest forms. Two hundred ten individuals from 18 states enrolled in the study from March 2014 to June 2015, and 195 were randomized. Most participants were white (96%) and college educated (73%). Of the randomized participants, 73% had seen a Parkinson's disease specialist within the previous year.

CONCLUSIONS

Among individuals with Parkinson's disease, national interest in receiving remote specialty care directly into the home is high. Remote enrollment in this care model is feasible but is likely affected by differential access to the Internet.

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.

Cardiac Valvulopathy Associated with Pergolide Use

OBJECTIVE

To review the risk of pergolide associated cardiac valvulopathy in patients with Parkinson's disease.

DATA SOURCES

MEDLINE, Embase, and the Cochrane Library. Reference lists were reviewed and librarians were consulted to identify additional trials.

STUDY SELECTION

All studies and case reports in the English literature on pergolide and cardiac valvulopathy.

DATA EXTRACTION

Demographics of patients, study duration, dose and duration of pergolide use, echocardiogram results, length of follow-up, and clinical outcome.

RESULTS

Twenty-two published articles were identified. There were no randomized controlled trials. Follow-up time varied between a few months and four years. Three case reports and four studies (three case control and one observational) assessed 246 patients. Evidence for valvulopathy was found in all studies. Variable methods were used to assess the degree of valvular regurgitation making comparisons between studies difficult. Little clinical correlation is available for echocardiogram results. Variable improvement was shown in the few patients in whom the drug was stopped. There is insufficient data to determine whether dose and duration or other comorbities have an effect on the risk of developing cardiac valvulopathy.

CONCLUSION

Pergolide therapy is associated with an increased risk of developing cardiac valvulopathy but the true incidence and importance of this remains unknown. Further prospective studies are needed with standardized assessments of echocardiograms.

Complementary & alternative management of Parkinson's disease: an evidence-based review of eastern influenced practices

The prevalence of Parkinson’s disease (PD) appears to be lower in Asia compared to the Western world. It is unclear if this is related to the ubiquitous use of traditional medicine in Eastern healthcare, but the use of complementary and alternative medicine (CAM) modalities in countries like Korea may be as high as 76%. Among patients with PD, herbal medicines, health supplement foods, and acupuncture are interventions which are increasingly used throughout the world. Countries like Korea, China, India, and Japan have long embraced and incorporated traditional medicine into modern management of conditions such as PD, but research into various CAM modalities remains in its infancy limiting evidence-based recommendations for many treatments. We reviewed the literature on CAM treatments for PD, focusing on mind-body interventions and natural products. Based on evidence limited to randomized-controlled trials we found that mind-body interventions are generally effective forms of physical activity that are likely to foster good adherence and may reduce disability associated with PD. Based on the current data, modalities like Tai Chi and dance are safe and beneficial in PD, but better studies are needed to assess the effects of other frequently used modalities such as yoga and acupuncture. Furthermore, despite centuries of experience using medicinal herbs and plants in Eastern countries, and despite substantial preclinical data on the beneficial effects of nutritional antioxidants as neuroprotective agents in PD, there is insufficient clinical evidence that any vitamin, food additive, or supplement, can improve motor function or delay disease progression in PD.

A randomized clinical trial of high-dosage coenzyme Q10 in early Parkinson disease: no evidence of benefit

IMPORTANCE

Coenzyme Q10 (CoQ10), an antioxidant that supports mitochondrial function, has been shown in preclinical Parkinson disease (PD) models to reduce the loss of dopamine neurons, and was safe and well tolerated in early-phase human studies. A previous phase II study suggested possible clinical benefit.

OBJECTIVE

To examine whether CoQ10 could slow disease progression in early PD.

DESIGN, SETTING, AND PARTICIPANTS

A phase III randomized, placebo-controlled, double-blind clinical trial at 67 North American sites consisting of participants 30 years of age or older who received a diagnosis of PD within 5 years and who had the following inclusion criteria: the presence of a rest tremor, bradykinesia, and rigidity; a modified Hoehn and Yahr stage of 2.5 or less; and no anticipated need for dopaminergic therapy within 3 months. Exclusion criteria included the use of any PD medication within 60 days, the use of any symptomatic PD medication for more than 90 days, atypical or drug-induced parkinsonism, a Unified Parkinson's Disease Rating Scale (UPDRS) rest tremor score of 3 or greater for any limb, a Mini-Mental State Examination score of 25 or less, a history of stroke, the use of certain supplements, and substantial recent exposure to CoQ10. Of 696 participants screened, 78 were found to be ineligible, and 18 declined participation.

INTERVENTIONS

The remaining 600 participants were randomly assigned to receive placebo, 1200 mg/d of CoQ10, or 2400 mg/d of CoQ10; all participants received 1200 IU/d of vitamin E.

MAIN OUTCOMES AND MEASURES

Participants were observed for 16 months or until a disability requiring dopaminergic treatment. The prospectively defined primary outcome measure was the change in total UPDRS score (Parts I-III) from baseline to final visit. The study was powered to detect a 3-point difference between an active treatment and placebo.

RESULTS

The baseline characteristics of the participants were well balanced, the mean age was 62.5 years, 66% of participants were male, and the mean baseline total UPDRS score was 22.7. A total of 267 participants required treatment (94 received placebo, 87 received 1200 mg/d of CoQ10, and 86 received 2400 mg/d of CoQ10), and 65 participants (29 who received placebo, 19 who received 1200 mg/d of CoQ10, and 17 who received 2400 mg/d of CoQ10) withdrew prematurely. Treatments were well tolerated with no safety concerns. The study was terminated after a prespecified futility criterion was reached. At study termination, both active treatment groups showed slight adverse trends relative to placebo. Adjusted mean changes (worsening) in total UPDRS scores from baseline to final visit were 6.9 points (placebo), 7.5 points (1200 mg/d of CoQ10; P = .49 relative to placebo), and 8.0 points (2400 mg/d of CoQ10; P = .21 relative to placebo).

CONCLUSIONS AND RELEVANCE

Coenzyme Q10 was safe and well tolerated in this population, but showed no evidence of clinical benefit.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00740714.

Circadian melatonin rhythm and excessive daytime sleepiness in Parkinson disease

IMPORTANCE

Diurnal fluctuations of motor and nonmotor symptoms and a high prevalence of sleep-wake disturbances in Parkinson disease (PD) suggest a role of the circadian system in the modulation of these symptoms. However, surprisingly little is known regarding circadian function in PD and whether circadian dysfunction is involved in the development of sleep-wake disturbances in PD.

OBJECTIVE

To determine the relationship between the timing and amplitude of the 24-hour melatonin rhythm, a marker of endogenous circadian rhythmicity, with self-reported sleep quality, the severity of daytime sleepiness, and disease metrics.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional study from January 1, 2009, through December 31, 2012, of 20 patients with PD receiving stable dopaminergic therapy and 15 age-matched control participants. Both groups underwent blood sampling for the measurement of serum melatonin levels at 30-minute intervals for 24 hours under modified constant routine conditions at the Parkinson's Disease and Movement Disorders Center of Northwestern University.

INTERVENTIONS

Twenty-four hour monitoring of serum melatonin secretion.

MAIN OUTCOMES AND MEASURES

Clinical and demographic data, self-reported measures of sleep quality (Pittsburgh Sleep Quality Index) and daytime sleepiness (Epworth Sleepiness Scale), and circadian markers of the melatonin rhythm, including the amplitude, area under the curve (AUC), and phase of the 24-hour rhythm.

RESULTS

Patients with PD had blunted circadian rhythms of melatonin secretion compared with controls; the amplitude of the melatonin rhythm and the 24-hour AUC for circulating melatonin levels were significantly lower in PD patients (P < .001). Markers of the circadian phase were not significantly different between the 2 groups. Compared with PD patients without excessive daytime sleepiness, patients with excessive daytime sleepiness (Epworth Sleepiness Scale score ≥10) had a significantly lower amplitude of the melatonin rhythm and 24-hour melatonin AUC (P = .001). Disease duration, Unified Parkinson's Disease Rating Scale scores, levodopa equivalent dose, and global Pittsburgh Sleep Quality Index score in the PD group were not significantly related to measures of the melatonin circadian rhythm.

CONCLUSIONS AND RELEVANCE

Circadian dysfunction may underlie excessive sleepiness in PD. The nature of this association needs to be explored further in longitudinal studies. Approaches aimed to strengthen circadian function, such as timed exposure to bright light and exercise, might serve as complementary therapies for the nonmotor manifestations of PD.

Impact of mild cognitive impairment on health-related quality of life in Parkinson's disease

BACKGROUND/AIMS

To assess the impact of mild cognitive impairment (MCI) or cognitive decline on health-related quality of life (HR-QOL) in Parkinson's disease (PD).

METHODS

HR-QOL measured by the Parkinson Disease Quality of Life Questionnaire (PDQ-39), MCI according to Movement Disorder Society Task Force criteria and cognitive decline from premorbid baseline were assessed in non-demented PD patients at 6 movement disorder clinics.

RESULTS

Among 137 patients, after adjusting for education, gender, disease duration, and Movement Disorder Society Unified Parkinson's Disease Rating Scale total score, MCI was associated with worse scores within the PDQ-39 dimension of communication (p = 0.008). Subjects were divided into tertiles of cognitive decline from premorbid level. Scores in the dimension of stigma were worst in the second tertile of cognitive decline (p = 0.03). MCI was associated with worse social support scores in the second tertile of cognitive decline (p = 0.008).

CONCLUSION

MCI and cognitive decline from premorbid baseline are associated with reduced HR-QOL in communication, stigma, and social support domains. The cognitive decline from premorbid baseline modifies the association between MCI and HR-QOL in PD and knowing both will allow a better appreciation of difficulties patients face in daily life.

Implicit perceptual-motor skill learning in mild cognitive impairment and Parkinson's disease

OBJECTIVE

Implicit skill learning is hypothesized to depend on nondeclarative memory that operates independent of the medial temporal lobe (MTL) memory system and instead depends on cortico striatal circuits between the basal ganglia and cortical areas supporting motor function and planning. Research with the Serial Reaction Time (SRT) task suggests that patients with memory disorders due to MTL damage exhibit normal implicit sequence learning. However, reports of intact learning rely on observations of no group differences, leading to speculation as to whether implicit sequence learning is fully intact in these patients. Patients with Parkinson's disease (PD) often exhibit impaired sequence learning, but this impairment is not universally observed.

METHOD

Implicit perceptual-motor sequence learning was examined using the Serial Interception Sequence Learning (SISL) task in patients with amnestic Mild Cognitive Impairment (MCI; n = 11) and patients with PD (n = 15). Sequence learning in SISL is resistant to explicit learning and individually adapted task difficulty controls for baseline performance differences.

RESULTS

Patients with MCI exhibited robust sequence learning, equivalent to healthy older adults (n = 20), supporting the hypothesis that the MTL does not contribute to learning in this task. In contrast, the majority of patients with PD exhibited no sequence-specific learning in spite of matched overall task performance. Two patients with PD exhibited performance indicative of an explicit compensatory strategy suggesting that impaired implicit learning may lead to greater reliance on explicit memory in some individuals.

CONCLUSION

The differences in learning between patient groups provides strong evidence in favor of implicit sequence learning depending solely on intact basal ganglia function with no contribution from the MTL memory system.

Matrix metalloproteinase levels in early HIV infection and relation to in vivo brain status

Matrix metalloproteinases (MMPs) have been implicated in human immunodeficiency virus (HIV)-associated neurological injury; however, this relationship has not been studied early in infection. Plasma levels of MMP-1, MMP-2, MMP-7, MMP-9, and MMP-10 measured using Luminex technology (Austin, TX, USA) were compared in 52 HIV and 21 seronegative participants of the Chicago Early HIV Infection study. MMP levels were also examined in HIV subgroups defined by antibody reactivity, viremia, and antiretroviral status, as well as in available cerebrospinal fluid (CSF) samples (n = 9). MMPs were evaluated for patterns of relationship to cognitive function and to quantitative magnetic resonance measurements of the brain derived in vivo. Plasma MMP-2 levels were significantly reduced in early HIV infection and correlated with altered white matter integrity and atrophic brain changes. MMP-9 levels were higher in the treated subgroup than in the naïve HIV subgroup. Only MMP-2 and MMP-9 were detected in the CSF; CSF MMP-2 correlated with white matter integrity and with volumetric changes in basal ganglia. Relationships with cognitive function were also identified. MMP-2 levels in plasma and in CSF correspond to early changes in brain structure and function. These findings establish a link between MMPs and neurological status previously unidentified in early HIV infection.

Measuring mild cognitive impairment in patients with Parkinson's disease

We examined the frequency of Parkinson disease with mild cognitive impairment (PD-MCI) and its subtypes and the accuracy of 3 cognitive scales for detecting PD-MCI using the new criteria for PD-MCI proposed by the Movement Disorders Society. Nondemented patients with Parkinson's disease completed a clinical visit with the 3 screening tests followed 1 to 3 weeks later by neuropsychological testing. Of 139 patients, 46 met Level 2 Task Force criteria for PD-MCI when impaired performance was based on comparisons with normative scores. Forty-two patients (93%) had multi-domain MCI. At the lowest cutoff levels that provided at least 80% sensitivity, specificity was 44% for the Montreal Cognitive Assessment and 33% for the Scales for Outcomes in Parkinson's Disease-Cognition. The Mini-Mental State Examination could not achieve 80% sensitivity at any cutoff score. At the highest cutoff levels that provided specificity of at least 80%, sensitivities were low (≤44%) for all tests. When decline from estimated premorbid levels was considered evidence of cognitive impairment, 110 of 139 patients were classified with PD-MCI, and 103 (94%) had multi-domain MCI. We observed dramatic differences in the proportion of patients who had PD-MCI using the new Level 2 criteria, depending on whether or not decline from premorbid level of intellectual function was considered. Recommendations for methods of operationalizing decline from premorbid levels constitute an unmet need. Among the 3 screening tests examined, none of the instruments provided good combined sensitivity and specificity for PD-MCI. Other tests recommended by the Task Force Level 1 criteria may represent better choices, and these should be the subject of future research.

Roles of Education and IQ in Cognitive Reserve in Parkinson's Disease-Mild Cognitive Impairment

Background/Aims

The role of cognitive reserve in Parkinson's disease (PD)-mild cognitive impairment (MCI) is incompletely understood.

Methods

The relationships between PD-MCI, years of education, and estimated premorbid IQ were examined in 119 consecutive non-demented PD patients using logistic regression models.

Results

Higher education and IQ were associated with reduced odds of PD-MCI in univariate analysis. In multivariable analysis, a higher IQ was associated with a significantly decreased odds of PD-MCI, but education was not.

Conclusion

The association of higher IQ and decreased odds of PD-MCI supports a role for cognitive reserve in PD, but further studies are needed to clarify the interaction of IQ and education and the impact of other contributors such as employment and hobbies.

Tolerability of isradipine in early Parkinson's disease: a pilot dose escalation study

Recent data suggests that isradipine, a dihydropyridine calcium channel blocker, is neuroprotective in preclinical models of parkinsonism. Isradipine has not been systematically studied in patients with Parkinson's disease (PD). The aim of this study was to evaluate safety and tolerability of isradipine controlled release (CR) in patients with early PD. Qualified subjects (n = 31) received isradipine CR, titrated from 5 to 20 mg daily dose over 8 weeks as tolerated. Eighty-one percent of subjects completed the study. Tolerability of isradipine CR was dose dependent: 94% for 5 mg dose; 87% for 10 mg; 68% for 15 mg; and 52% for 20 mg. Isradipine had no significant effect on blood pressure or PD motor disability. The two most common reasons for dose reduction were leg edema (7) and dizziness (3). There was no difference in isradipine tolerability between subjects with and without dopaminergic treatment, or with and without hypertension.

Brain donation--what do patients with movement disorders know and how do they feel about it?

A 30-item self-completed survey was administered to 216 consecutive patients with various movement disorders in order to assess their knowledge base, perceptions, and beliefs about brain donation. Two hundred three surveys were analyzed. While 78% of study participants did not know about brain donation before completing the survey, 56% would be willing to consider brain donation. Willingness to consider brain donation is not significantly different between genders, or influenced by the degree of religious involvement, marital status, or disease duration. Majority of the study participants consider discussions about brain donation appropriate during regular clinic visits. Younger participants were more likely to consider brain donation. Major motivating factors to pursue brain donation were advancement of medical knowledge, providing hope and purpose for others, and advancing our understanding of hereditability of a disorder that may impact surviving family members. We advocate proactive education of patients with various movement disorders about the purpose and benefits of brain donation.

Suppression of deep brain stimulation artifacts from the electroencephalogram by frequency-domain Hampel filtering

OBJECTIVE

Currently, electroencephalography (EEG) cannot be used to record cortical activity during clinically effective DBS due to the presence of large stimulation artifact with components that overlap the useful spectrum of the EEG. A filtering method is presented that removes these artifacts whilst preserving the spectral and temporal fidelity of the underlying EEG.

METHODS

The filter is based on the Hampel identifier that treats artifacts as outliers in the frequency domain and replaces them with interpolated values. Performance of the filter was tested with a synthesized DBS signal and actual data recorded during bilateral monopolar DBS.

RESULTS

Mean increases in signal-to-noise ratio of 7.8dB for single-frequency stimulation and 13.8dB for dual-frequency stimulation are reported. Correlation analysis between EEG with synthesized artifacts and artifact-free EEG reveals that distortion to the underlying EEG in the filtered signal is negligible (r(2)>0.99).

CONCLUSIONS

Frequency-domain Hampel filtering has been shown to remove monopolar DBS artifacts under a number of common stimulation conditions used for the treatment of Parkinson's disease.

SIGNIFICANCE

Application of frequency-domain Hampel filtering will allow the measurement of EEG in patients during clinically effective DBS and thus may increase our understanding of the mechanisms of action of this important therapeutic intervention.

A comparison of the mini mental state exam to the Montreal cognitive assessment in identifying cognitive deficits in Parkinson's disease

Dementia is an important and increasingly recognized problem in Parkinson's disease (PD). The mini-mental state examination (MMSE) often fails to detect early cognitive decline. The Montreal cognitive assessment (MoCA) is a brief tool developed to detect mild cognitive impairment that assesses a broader range of domains frequently affected in PD. The scores on the MMSE and the MoCA were compared in 88 patients with PD. A pronounced ceiling effect was observed with the MMSE but not with the MoCA. The range and standard deviation of scores was larger with the MoCA(7-30, 4.26) than with the MMSE(16-30, 2.55). The percentage of subjects scoring below a cutoff of 26/30 (used by others to detect mild cognitive impairment) was higher on the MoCA (32%) than on the MMSE (11%) (P < 0.000002). Compared to the MMSE, the MoCA may be a more sensitive tool to identify early cognitive impairment in PD.

Location of Active Contacts in Patients with Primary Dystonia Treated with Globus Pallidus Deep Brain Stimulation

Objective:

Deep brain stimulation of the globus pallidus internus has been used for the treatment of various forms of dystonia, but the factors influencing postoperative outcomes remain unknown. We compared the location of the contacts being used for stimulation (active contacts) in patients with cervical dystonia, generalized dystonia, and Parkinson's disease and correlated the results with clinical outcome.

Methods:

Postoperative magnetic resonance scans of 13 patients with cervical dystonia, six patients with generalized dystonia, and five patients with Parkinson's disease who underwent globus pallidus internus deep brain stimulation were analyzed. We assessed the location of the active contacts relative to the midcommisural point and in relation to the anteroposterior and mediolateral boundaries of the pallidum. Postoperative outcome was measured with the Toronto Western Spasmodic Torticollis Rating Scale (for cervical dystonia) and the Burke-Fahn-Marsden Dystonia Rating Scale (for generalized dystonia) during the last follow-up.

Results:

We found that the location of the active contacts relative to the midcom-misural point and the internal boundaries of the pallidum was similar across the groups. In our series, the contacts used for stimulation were clustered in the posterolateral region of the pallidum. Within that region, we found no correlation between the location of the contacts and postoperative outcome.

Conclusion:

The location of the active contacts used for globus pallidus internus deep brain stimulation was similar in patients with cervical dystonia, generalized dystonia, and Parkinson's disease.

Movement disorders in patients taking anticonvulsants

BACKGROUND

A wide variety of movement disorders may occur as a consequence of the administration of antiepileptic drugs (AEDs). Although it has been suggested that the risk of parkinsonism is 10-fold higher in those taking valproate as compared with other AEDs, there have been no large, systematic trials assessing this.

AIM

To establish more precisely the prevalence of and risk factors for developing parkinsonism associated with valproate use,and to assess the occurrence of movement disorders with the newer AEDs.

METHODS

Patients with epilepsy were recruited from the Toronto Western Hospital Epilepsy Clinic (University of Toronto, Toronto, Ontario, Canada). Each patient was examined by a movement disorder specialist who was blinded to the treatment status of the patient.

RESULTS

201 patients were included. Postural tremor was the most common movement disorder (45%), followed by parkinsonism (4.5%). The odds of having parkinsonism were 5 times higher with valproate than with other AEDs. No single factor predicted the presence of parkinsonism; however, many (5/9) of the patients concurrently used other drugs or had comorbidities that could have caused or exacerbated parkinsonism. None of the newer AEDs were clearly associated with the presence of movement disorders; however, the numbers were too small to make a formal analysis.

CONCLUSION

Although the risk of parkinsonism with valproate is higher than with other AEDs, it is lower than originally reported. The cases available were not enough to accurately comment on the prevalence of movement disorders with the newer AEDs.

Homozygous and heterozygous PINK1 mutations: considerations for diagnosis and care of Parkinson's disease patients

The first mutations described in PINK1 were homozygous. More recently, heterozygous mutations have been reported but the role of heterozygosity in disease pathogenesis is still debated. We describe two unrelated cases with PINK1 mutations (homozygous nonsense and heterozygous missense) that highlight issues regarding the role of heterozygous mutations and the utility of genetic screening in patient care.

Childhood onset in familial prion disease with a novel mutation in the PRNP gene

BACKGROUND

Up to 15% of cases of prion diseases are due to the autosomal dominant inheritance of coding PRNP mutations.

OBJECTIVE

To describe the unique clinical and genetic findings in a family of East Indian origin with autosomal dominant inheritance of a novel PRNP mutation.

DESIGN

Detailed neurological examination and sequencing analysis of the MAPT and PRNP genes.

SETTING

Toronto Western Hospital, Toronto, Ontario.

PATIENTS

Five available members of a family of East Indian origin with a rapidly progressive neurodegenerative disorder characterized by dementia, motor decline, and ataxia.

RESULTS

We identified a novel Pro105Thr mutation in the PRNP gene in all of the 3 clinically affected family members but not in their unaffected relatives or normal controls. Although 5 of 6 affected family members had a relatively homogeneous phenotype and age at onset (range, 33-41 years), 1 of the 6 patients developed the disease at age 13 years.

CONCLUSIONS

A novel mutation in the PRNP gene was identified in all of the available, clinically affected members of this family with a rapidly progressive neurodegenerative disease. To our knowledge, the propositus represents the youngest individual with inherited prion disease described to date.

Vitamins and entacapone in levodopa-induced hyperhomocysteinemia: A randomized controlled study

Elevated homocysteine is associated with increased risk of heart disease, stroke, and dementia. Therapy of Parkinson disease (PD) with levodopa elevates homocysteine. The authors conducted a 6-week, multicenter, randomized, double-blind, placebo-controlled trial to test whether folate 1 mg/vitamin B(12) 500 microg or entacapone reduced serum homocysteine in 35 levodopa-treated PD patients. Levodopa initiation caused a small elevation in homocysteine. Vitamin therapy, but not entacapone, resulted in a decrease in homocysteine compared to placebo.

The 'essentials' of essential palatal tremor: a reappraisal of the nosology

Essential palatal tremor (EPT) is an uncommon disorder, distinct from symptomatic palatal tremor (SPT), but characterized by superficially similar rhythmic movements of the soft palate. While the pathophysiology of SPT has been relatively well defined, this is not the case in EPT. Based on an analysis of 103 published cases, we reviewed EPT in the context of other movement disorders with similar features and outline possible pathophysiological mechanisms. Phenomenologically it remains best classified as a tremor. Four major causes, including a central generator, peripheral/mechanical, voluntary/special skill and psychogenic, appear to account for the majority of cases of EPT, although there is considerable overlap in the pathogenic mechanisms underlying these categories. Among the cases reviewed, a large proportion fit into the latter two categories, although there are others where multiple mechanisms are likely at play. Based on our reappraisal, we suggest a change in designation to 'isolated palatal tremor', with primary and secondary subtypes. This retains the distinction from SPT and emphasizes the non-uniform, heterogeneous nature of the disorder.

Apraxia in movement disorders

The definition of apraxia specifies that the disturbance of performed skilled movements cannot be explained by the more elemental motor disorders typical of patients with movement disorders. Generally this does not present a significant diagnostic problem when dealing with 'higher-level' praxic disturbances (e.g. ideational apraxia), but it can be a major confound in establishing the presence of limb-kinetic apraxia. Most motor disturbances characteristic of extrapyramidal disorders, particularly bradykinesia and dystonia, will compromise the ability to establish the presence of loss of dexterity and deftness that constitutes this subtype. The term 'apraxia' has also been applied to other motor disturbances, such as 'gait apraxia' and 'apraxia of eyelid opening', that perhaps are misnomers, demonstrating the lack of a coherent nomenclature in this field. Apraxia is a hallmark of corticobasal degeneration (CBD) and historically this has received the most attention among the movement disorders. Corticobasal degeneration is characterized by various forms of apraxia affecting limb function, particularly ideomotor apraxia and limb-kinetic apraxia, although buccofacial and oculomotor apraxia can be present as well. The syndrome of parkinsonism and prominent apraxia, designated the 'corticobasal syndrome' (CBS), may be caused by a variety of other central nervous system pathologies including progressive supranuclear palsy (PSP), Alzheimer's disease, dementia with Lewy bodies and frontotemporal dementias. Distinct from the CBS, PSP and Parkinson's disease can demonstrate varying degrees of apraxia on selected tests, especially in those patients with more severe cognitive dysfunction. Diseases that cause the combination of apraxia and a primary movement disorder most often involve a variety of cerebral cortical sites as well as basal ganglia structures. Clinical-pathological correlates and functional imaging studies are compromised by both this diffuse involvement and the confusion experienced in the clinical evaluation of apraxia in the face of the additional elemental movement disorders. Finally, although apraxia results in clear disability in patients with the CBS, it is not clear how milder ideomotor apraxia found on specific testing contributes to patients' overall day-to-day motor disability.