What predicts falls in Parkinson disease?: Observations from the Parkinson's Foundation registry

BACKGROUND

We undertook this study to identify patients with Parkinson disease (PD) with no or rare falls who may progress to frequent falling by their next annual follow-up visit.

METHODS

We analyzed data in the National Parkinson Foundation Quality Improvement Initiative database to identify factors predicting which patients with PD with no or rare falls at the baseline visit will report at least monthly falls at the annual follow-up visit. Multivariable models were constructed using logistic regression. Variables were introduced in 4 blocks: in the 1st block, variables present at or before the baseline visit were entered; in the 2nd, baseline visit assessments; in the 3rd, interventions implemented during baseline visit; and, in the 4th block, changes in comorbidities, living situation, and treatment between visits.

RESULTS

Of 3,795 eligible participants, 3,276 (86.3%) reported no or rare falls at baseline visit, and of them, 382 (11.7%) reported at least monthly falls at follow-up visit. Predictors included female sex, <90% diagnostic certainty, motor fluctuations, levodopa treatment, antidepressant treatment, prior deep brain stimulation (DBS), worse quality of life, Hoehn & Yahr stage 2 or 3, worse semantic fluency, and, between visits, addition of amantadine, referral to occupational therapy, social services, or DBS, new diagnoses of cancer or osteoarthritis, and increased emergency visits.

CONCLUSIONS

This large-scale analysis identified several predictors of progression to falling in PD. Such identifiers may help target patient subgroups for falls prevention intervention. Some factors are modifiable, offering opportunities for developing such interventions.

Amantadine extended-release capsules for levodopa-induced dyskinesia in patients with Parkinson's disease

Levodopa-induced dyskinesia (LID) is a common motor complication in patients with Parkinson's disease on chronic levodopa therapy. The management of LID is important as dyskinesia can be disabling and impair quality of life. Currently, there are limited treatment options for the medical management of LID. Amantadine extended-release capsules (Gocovri™) is the first medication that received US Food and Drug Administration approval for the treatment of LID. The following is a review of the pharmacodynamics, efficacy and safety profile, and current state of treatment of amantadine for LID.

Pupillary Response to Cognitive Demand in Parkinson's Disease: A Pilot Study

Previous studies have shown that pupillary response, a physiological measure of cognitive workload, reflects cognitive demand in healthy younger and older adults. However, the relationship between cognitive workload and cognitive demand in Parkinson's disease (PD) remains unclear. The aim of this pilot study was to examine the pupillary response to cognitive demand in a letter-number sequencing (LNS) task between 16 non-demented individuals with PD (age, median (Q1-Q3): 68 (62-72); 10 males) and 10 control participants (age: 63 (59-67); 2 males), matched for age, education, and Montreal Cognitive Assessment (MOCA) scores. A mixed model analysis was employed to investigate cognitive workload changes as a result of incremental cognitive demand for both groups. As expected, no differences were found in cognitive scores on the LNS between groups. Cognitive workload, exemplified by greater pupil dilation, increased with incremental cognitive demand in both groups (p = 0.003). No significant between-group (p = 0.23) or interaction effects were found (p = 0.45). In addition, individuals who achieved to complete the task at higher letter-number (LN) load responded differently to increased cognitive demand compared with those who completed at lower LN load (p < 0.001), regardless of disease status. Overall, the findings indicated that pupillary response reflects incremental cognitive demand in non-demented people with PD and healthy controls. Further research is needed to investigate the pupillary response to incremental cognitive demand of PD patients with dementia compared to non-demented PD and healthy controls. Highlights -Pupillary response reflects cognitive demand in both non-demented people with PD and healthy controls-Although not significant due to insufficient power, non-demented individuals with PD had increased cognitive workload compared to the healthy controls throughout the testing-Pupillary response may be a valid measure of cognitive demand in non-demented individuals with PD-In future, pupillary response might be used to detect cognitive impairment in individuals with PD.

Symptomatic, non-infectious, non-hemorrhagic edema after subthalamic nucleus deep brain stimulation surgery for Parkinson's disease

OBJECT

We review our experience with Parkinson's disease (PD) patients who underwent subthalamic nucleus (STN) deep brain stimulation (DBS) and then developed noninfectious, non-hemorrhagic, delayed, symptomatic brain edema associated with a DBS lead.

METHODS

All PD patients who underwent STN DBS lead implantation from 2007 to 2015 were included. The same neurosurgeon performed all surgeries, typically in staged fashion, utilizing single pass microelectrode recordings (MER) within a stereotactic frame. A brain CT was obtained in recovery and subsequently if indicated.

RESULTS

There were 189 patients who underwent 363 STN lead implantations among which 35 (9.6%) represent re-implantations of removed leads in 28 (14.8%) patients. Among the 363 STN leads implanted, there were 12 (3.3%) cases of delayed symptomatic edema associated with a DBS lead involving 10 (5.3%) of the patients studied. Of the 328 leads representing first-time operations, there were 9 (2.1%) cases of delayed symptomatic edema in 7 (3.7%) patients, one of whom (14.3%) presented with seizures. For lead re-implantations, there were 3 (8.6%) cases of the brain edema in 3 (10.7%) patients; all presenting with seizures. For the 35 re-implantations, the trajectory to target was the same or very similar via the same burr hole as prior surgery in 17 (48.6%); 3 (17.6%) of whom developed edema. There was no case of brain edema in the 18 re-operated cases using a different burr opening. Edema patients were treated with a course of anticonvulsant medication and dexamethasone. Lead-associated edema resolved over generally a 4 to 6-week course.

CONCLUSIONS

Noninfectious, non-hemorrhagic, delayed, symptomatic brain edema occurs in approximately 3% of implanted leads and is more common in re-implantations (9%) compared to new implantations (2%). In re-implantations, the edema is more common when the same trajectory is used (18%) compared to a new trajectory (0%). The edema generally occurs 3 to 8 days after implantation, although immediate post-op CT is normal and seizures are a common presenting feature.

ADS-5102 (Amantadine) Extended-Release Capsules for Levodopa-Induced Dyskinesia in Parkinson Disease (EASE LID Study): A Randomized Clinical Trial

Importance

Medical treatment of levodopa-induced dyskinesia (LID) in Parkinson disease (PD) is an unmet need.

Objective

To evaluate the efficacy and safety of ADS-5102 (amantadine) extended-release 274-mg capsules for treatment of LID in patients with PD.

Design, Setting, and Participants

A randomized, double-blind, placebo-controlled clinical trial was conducted between May 7, 2014, and July 22, 2015, at 44 North American sites among patients with PD treated with levodopa who experienced at least 1 hour of troublesome dyskinesia per day with at least mild functional impact.

Interventions

Patients were randomized to receive placebo or 274 mg of ADS-5102 administered orally at bedtime for up to 25 weeks.

Main Outcomes and Measures

The primary efficacy analysis was the change from baseline to week 12 in the Unified Dyskinesia Rating Scale total score for ADS-5102 vs placebo in the modified intent-to-treat population. OFF time (amount of time the PD medication is not controlling motor symptoms) was a key secondary end point. Safety analyses included all patients who received the study drug (ADS-5102 or placebo).

Results

A total of 189 patients were screened, and 126 were randomized; the modified intent-to-treat population included 121 patients (51 women and 70 men; mean [SD] age, 64.7 [9.1] years). At week 12, the least-squares mean (SE) change in the Unified Dyskinesia Rating Scale score was -15.9 (1.6) for ADS-5102 (n = 63) and -8.0 (1.6) for placebo (n = 58) (treatment difference, -7.9; 95% CI, -12.5 to -3.3; P < .001). OFF time decreased by a mean (SE) of 0.6 (0.3) hours for ADS-5102 and increased by 0.3 (0.3) hours for placebo (treatment difference, -0.9 hours; 95% CI, -1.6 to -0.2; P = .02). Common adverse events for ADS-5102 vs placebo included visual hallucinations (15 [23.8%] vs 1 [1.7%]), peripheral edema (15 [23.8%] vs 0), and dizziness (14 [22.2%] vs 0). Adverse events led to treatment discontinuation for 13 patients receiving ADS-5102 (20.6%) vs 4 patients receiving placebo (6.9%).

Conclusions and Relevance

ADS-5102, 274 mg at bedtime, may be an effective treatment for LID. An additional benefit is reduced OFF time. To our knowledge, this is the first demonstration of an oral treatment reducing both LID and OFF time in patients with PD with dyskinesia.

Trial Registration

clinicaltrials.gov Identifier: NCT02136914.

Rating Scales for Pain in Parkinson's Disease: Critique and Recommendations

BACKGROUND

We aimed at critically appraising the clinimetric properties of existing pain scales or questionnaires and to give recommendations for their use in Parkinson's disease (PD).

METHODS

Clinimetric properties of pain scales used in PD were systematically evaluated. A scale was classified as 'recommended' if was used in PD, showed adequate clinimetric properties, and had been used by investigators other than the original developers; as 'suggested' if it was used in PD and fulfilled only one other criterion; and as 'listed' if it was used in PD but did not meet the other criteria. Only scales rating pain intensity or for syndromic classification were assessed.

RESULTS

Eleven of the 34 scales initially considered fulfilled inclusion criteria. Among the scales rating pain intensity, the "Brief Pain Inventory short form," "McGill Pain Questionnaire short and long forms," "Neuropathic Pain Symptoms Inventory," "11-point Numeric Rating Scale," "10-cm Visual Analog Scale," and "Pain-O-Meter" were "recommended with caution" because of lack of clinimetric data in PD, whereas the "King's PD Pain Scale" was "recommended." Among scales for pain syndromic classification, the "DN4" was "recommended with caution" because of lack of clinimetric data in PD; the "Leeds Assessment of Neuropathic Symptoms and Signs," "Pain-DETECT," and the "King's PD Pain Scale" were "suggested."

CONCLUSIONS

King's PD pain scale can be recommended for the assessment of pain intensity in PD. Syndromic classification of pain in PD may be achieved by the DN4, but clinimetric data in PD are needed for this scale.

Deep brain stimulation for Parkinson's disease: current status and future outlook

Parkinson's disease is a neurodegenerative condition secondary to loss of dopaminergic neurons in the substantia nigra pars compacta. Surgical therapy serves as an adjunct when unwanted medication side effects become apparent or additional therapy is needed. Deep brain stimulation emerged into the forefront in the 1990s. Studies have demonstrated improvement in all of the cardinal parkinsonian signs with stimulation. Frameless and ‘mini-frame’ stereotactic systems, improved MRI for anatomic visualization, and intraoperative MRI-guided placement are a few of the surgical advances in deep brain stimulation. Other advances include rechargeable pulse generators, voltage- or current-based stimulation, and enhanced abilities to ‘steer’ stimulation. Work is ongoing investigating closed-loop ‘smart’ stimulation in which stimulation is predicated on neuronal feedback.

Transducer-based evaluation of tremor

The International Parkinson and Movement Disorder Society established a task force on tremor that reviewed the use of transducer-based measures in the quantification and characterization of tremor. Studies of accelerometry, electromyography, activity monitoring, gyroscopy, digitizing tablet-based measures, vocal acoustic analysis, and several other transducer-based methods were identified by searching PubMed.gov. The availability, use, acceptability, reliability, validity, and responsiveness were reviewed for each measure using the following criteria: (1) used in the assessment of tremor; (2) used in published studies by people other than the developers; and (3) adequate clinimetric testing. Accelerometry, gyroscopy, electromyography, and digitizing tablet-based measures fulfilled all three criteria. Compared to rating scales, transducers are far more sensitive to changes in tremor amplitude and frequency, but they do not appear to be more capable of detecting a change that exceeds random variability in tremor amplitude (minimum detectable change). The use of transducer-based measures requires careful attention to their limitations and validity in a particular clinical or research setting. © 2016 International Parkinson and Movement Disorder Society.

The characterization of a base-width neutral step as the first step for balance recovery in moderate Parkinson's disease

PURPOSE

The purpose of this study is to characterize the base-width neutral step (BNS) as the first step in a compensatory step response in persons with moderate Parkinson's disease (PD), and its effect on balance recovery.

MATERIALS AND METHODS

Ten PD and 10 healthy controls (HCs) responded to a posterior waist pull. A BNS was defined if the first step was less than 50 mm. The length, height, duration and velocity of the BNS and its effect on balance recovery time and center of mass location at recovery were compared to the first step within other stepping strategies (single step (SS), multiple step (MS)). A linear mixed model was used to compare across strategies.

RESULTS

Six of ten persons with PD compared to zero HC used a BNS. The BNS was shorter in length and duration compared to MS responses in HC, and shorter in duration compared to MS responses in PD. The BNS was slower in velocity compared to every other strategy. BNS use resulted in a longer recovery time compared to all strategies in HC and SS responses in PD, and trended toward a longer recovery time compared to MS responses in PD.

CONCLUSIONS

The BNS as the first step in a MS response may be an unreported strategy for compensatory stepping in PD. This study suggests that the cost of utilizing the BNS may be a longer time for recovery, but further work is necessary to understand the progression of the BNS as PD severity increases.

Validation of the QUEST for German-speaking countries

OBJECTIVE

To explore the clinimetric attributes of the German version of the quality of life in essential tremor (ET) questionnaire (QUEST) as a tremor-specific measure of quality of life.

METHODS

This was an observational, cross-sectional study. The QUEST German version was obtained by translation-back translation procedure. ET cases were diagnosed according to the tremor investigation group criteria. Assessments included Archimedes spirals rating, EQ-5D, Beck Depression Inventory (BDI-II) and QUEST German version. Missing data were imputed for those cases in which the loss of data for one domain of the QUEST was <30%.

RESULTS

Ninety three patients out of 138 (67.4%) with definite or probable ET had complete QUEST data after 43 item imputations and they constituted the sample for this study. The QUEST summary index (QSI) displayed no floor or ceiling effects. QUEST internal consistency (Cronbach's alpha) ranged between 0.50 and 0.89. Item-total domain correlations ranged from 0.26 to 0.82 and the item homogeneity indexes were satisfactory (range: 0.28-0.60). The QSI correlated weakly with the EQ-5D (rS=0.20) and moderately with the BDI-II (rS = 0.31) and the QUEST self-evaluation of tremor severity (rS = 0.44).

CONCLUSIONS

The QUEST German version has, despite recognized data quality problems, satisfactory acceptability and internal consistency as a whole. The correlation analysis showed that tremor in the head, voice and right hand was moderately associated with quality of life.

Proceedings of the Second Annual Deep Brain Stimulation Think Tank: What's in the Pipeline

The proceedings of the 2nd Annual Deep Brain Stimulation Think Tank summarize the most contemporary clinical, electrophysiological, and computational work on DBS for the treatment of neurological and neuropsychiatric disease and represent the insights of a unique multidisciplinary ensemble of expert neurologists, neurosurgeons, neuropsychologists, psychiatrists, scientists, engineers and members of industry. Presentations and discussions covered a broad range of topics, including advocacy for DBS, improving clinical outcomes, innovations in computational models of DBS, understanding of the neurophysiology of Parkinson's disease (PD) and Tourette syndrome (TS) and evolving sensor and device technologies.

Qigong exercise may improve sleep quality and gait performance in Parkinson's disease: a pilot study

PURPOSE

Parkinson's disease (PD) involves a variety of motor and non-motor symptoms, several of which, including gait abnormalities and sleep disorders, are generally not adequately managed with standard therapy. This study aimed to determine the impact of Qigong as a potential complementary therapy in the management of gait and sleep-related symptoms in PD.

METHODS

Seven subjects (aged 66.9 ± 8.1 years) with PD participated in a six-week Qigong exercise intervention. Pre- and post-intervention testing was performed to assess sleep quality, cognitive function, fatigue, quality of life, gait performance (stride time, stride length, double support time, and velocity), and gait variability (stride time and length variability).

RESULTS

Following Qigong, subjects showed improvement in some aspects of sleep quality. Fatigue remained unchanged. Gait function was improved by a significant reduction of stride time and a slight increase in stride length. Together these changes resulted in significant improvements to gait velocity. In addition, time spent in double limb support was reduced following the intervention. Overall gait variability improved significantly, particularly in the reduction of stride time variability.

CONCLUSIONS

These results suggest that Qigong may provide benefit for gait performance and sleep quality in PD patients. However, larger, controlled studies are required to determine the immediate and long-term benefits of Qigong for PD sleep and gait problems as well as the impact on other aspects of the disease.

Continuous infusion of levodopa-carbidopa intestinal gel in Parkinson's disease

Evaluation of: Olanow CW, Kieburtz K, Odin P et al. Continuous intrajejunal infusion of levodopa-carbidopa intestinal gel for patients with advanced Parkinson's disease: a randomised, controlled, double-blind, double-dummy study. Lancet Neurol. 13(2), 141-149 (2014). Levodopa-induced motor complications, including motor fluctuations and dyskinesia, can be a major source of disability for Parkinson's disease patients. The development of levodopa-induced motor complications has been attributed to the pulsatile dopaminergic stimulation characteristic of conventional oral levodopa regimens. This is a review of a 12-week, randomized, controlled, double-blind, double-dummy study of continuous jejunal infusion of levodopa-carbidopa intestinal gel to determine if the continuous infusion of levodopa reduces motor complications in Parkinson's disease. Results demonstrated that levodopa-carbidopa intestinal gel significantly reduced off-time without increasing troublesome dyskinesia compared with standard oral levodopa therapy. Adverse effects were common in both the levodopa-carbidopa intestinal gel and placebo groups and were related primarily to the infusion hardware.

Peptidoglycan recognition protein genes and risk of Parkinson's disease

Increased gut permeability, inflammation, and colonic α-synuclein pathology are present in early Parkinson's disease (PD) and have been proposed to contribute to PD pathogenesis. Peptidoglycan is a structural component of the bacterial cell wall. Peptidoglycan recognition proteins (PGRPs) maintain healthy gut microbial flora by regulating the immune response to both commensal and harmful bacteria. We tested the hypothesis that variants in genes that encode PGRPs are associated with PD risk. Participants in two independent case-control studies were genotyped for 30 single-nucleotide polymorphisms (SNPs) in the four PGLYRP genes. Using logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) adjusted for potential confounding variables, we conducted analyses in each study, separately and pooled. One SNP failed the assay, and three had little to no variation. The ORs were similar in both study populations. In pooled analyses, three of seven PGLYRP2 SNPs (rs3813135, rs733731, rs892145), one of five PGLYRP3 SNPs (rs2987763), and six of nine PGLYRP4 SNPs (rs10888557, rs12063091, rs3006440, rs3006448, rs3006458, and rs3014864) were significantly associated with PD risk. Association was strongest for PGLYRP4 5'untranslated region (UTR) SNP rs10888557 (GG reference, CG OR 0.6 [95%CI 0.4-0.9], CC OR 0.15 [95%CI 0.04-0.6]; log-additive P-trend, 0.0004). Common variants in PGLYRP genes are associated with PD risk in two independent studies. These results require replication, but they are consistent with hypotheses of a causative role for the gut microbiota and gastrointestinal immune response in PD.

The effect of moderate Parkinson's disease on compensatory backwards stepping

Postural instability is a major unmet need in the treatment of Parkinson's disease (PD) and its progression is not well understood. This study examined compensatory stepping taken in response to a backwards waist pull in participants with moderate PD (H&Y III) compared to age-range matched healthy controls (HC). The first step in the response was quantified in terms of strategy, temporal, kinematic, and center of pressure (COP) parameters previously observed to be significantly different in mild PD (H&Y II) compared to HC. Patients with moderate PD, compared to HC, utilized more steps to regain balance, had a longer weight-shift-time, and utilized a base-width neutral step to regain balance. However, there were no differences in ankle angle or COP location at landing as observed in mild PD, possibly due to the use of the base-width neutral step. These results suggest that moderate PD significantly impairs the compensatory response to a backwards pull. Further study should examine the progression of impairment in compensatory responses across PD severity levels, and the correlation with fall risk.

A Comparative White Matter Study with Parkinson's disease, Parkinson's Disease with Dementia and Alzheimer's Disease

Alzheimer's disease (AD) and Parkinson's disease (PD) are among the most common neurodegenerative disorders affecting older populations. AD is characterized by impaired memory and cognitive decline while the primary symptoms of PD include resting tremor, bradykinesia and rigidity. In PD, mild cognitive changes are frequently present, which could progress to dementia (PD dementia (PDD)). PDD and AD dementias are different in pathology although the difference in microstructural changes remains unknown. To further understand these diseases, it is essential to understand the distinct mechanism of their microstructural changes. We used diffusion tensor imaging (DTI) to investigate white matter tract differences between early stage individuals with AD (n=14), PD (n=12), PDD (n=9), and healthy non-demented controls (CON) (n=13). We used whole brain tract based spatial statistics (TBSS) and a region of interest (ROI) analysis focused on the substantia nigra (SN). We found that individuals with PDD had more widespread white matter degeneration compared to PD, AD, and CON. Individuals with AD had few regional abnormalities in the anterior and posterior projections of the corpus callosum while PD and CON did not appear to have significant white matter degeneration when compared to other groups. ROI analyses showed that PDD had the highest diffusivity in the SN and were significantly different from CON. There were no significant ROI differences between CON, PD, or AD. In conclusion, global white matter microstructural deterioration is evident in individuals with PDD, and DTI may provide a means with which to tease out pathological differences between AD and PD dementias.

Outcomes of rotigotine clinical trials: effects on motor and nonmotor symptoms of Parkinson's disease

Rotigotine transdermal system is a nonergot, 24-hour dopamine agonist approved for the treatment of early and advanced Parkinson's disease (PD). Recent studies have demonstrated significant improvements with rotigotine in motor function in early PD and significant improvements in daily off-time and motor function in advanced PD. In addition to motor improvements, nonmotor symptoms have been shown to be improved with rotigotine in both early and advanced PD. Rotigotine has been shown in large, controlled studies to be safe and efficacious for the treatment of motor and some nonmotor symptoms of early and advanced PD.

Predictors of mild cognitive impairment in early-stage Parkinson's disease

Aim

The aim of this study was to identify mild cognitive deficits in Parkinson's disease (PD) prior to extensive neurodegeneration and to evaluate the extent to which dopamine depletion and other disease-related predictors can explain cognitive profiles.

Methods

Neuropsychological performances of 40 nondemented early-stage PD patients and 42 healthy controls were compared across on or off dopaminergic medications. Stepwise regression evaluated cognitive predictors of early-stage PD and disease-related predictors of PD cognition (levodopa dose, disease duration, Unified Parkinson's Disease Rating Scale score, sleep, quality of life, and mood) across on and off states.

Results

Neuropsychological performance was lower in PD patients across cognitive domains with significant memory, naming, visuomotor, and complex attention/executive deficits, but with intact visuospatial, simple attention, and phonemic fluency functions. However, medication effects were absent except for simple attention. Regression analyses revealed age, working memory, and memory recall to be the best cognitive predictors of PD, while age, quality of life, disease duration, and anxiety predicted PD cognition in the off state.

Conclusion

Nondemented early-stage PD patients presented with extensive mild cognitive deficits including prominent memory impairment. The profile was inconsistent with expected isolated frontostriatal dysfunction previously attributed to dopamine depletion and this highlights the need to further characterize extranigral sources of mild cognitive impairment in PD.

Deep brain stimulation for essential tremor

Essential tremor is the most common tremor disorder and is characterized by a postural and kinetic tremor. Most commonly, the disease involves the upper extremities, although other body parts may be affected. Essential tremor is seen most often in adults and may markedly limit abilities to perform daily activities. Medications often fail to control the tremor adequately. In the past, ventral intermediate nucleus of the thalamus (VIM) thalamotomy was the surgery of choice for medication-resistant patients with disabling tremor. With technological advances, deep brain stimulation (DBS) to the VIM has replaced thalamotomy as the operation of choice for patients with essential tremor, given the heightened risk of permanent neurological deficits associated with ablative surgery. Multiple studies have demonstrated that unilateral VIM DBS has significant short- and long-term benefits for targeted tremor. Unilateral VIM DBS may also improve head and voice tremor, although most commonly bilateral stimulation is required for adequate control. However, bilateral thalamic stimulation is associated with a higher incidence of neurological deficits, particularly speech and gait problems. Investigations of DBS of other brain target areas for essential tremor, such as the posterior subthalamic area and the subthalamic nucleus, are ongoing.