Effect of Urate-Elevating Inosine on Early Parkinson Disease Progression: The SURE-PD3 Randomized Clinical Trial.

Importance: Urate elevation, despite associations with crystallopathic, cardiovascular, and metabolic disorders, has been pursued as a potential disease-modifying strategy for Parkinson disease (PD) based on convergent biological, epidemiological, and clinical data. Objective: To determine whether sustained urate-elevating treatment with the urate precursor inosine slows early PD progression. Design, Participants, and Setting: Randomized, double-blind, placebo-controlled, phase 3 trial of oral inosine treatment in early PD. A total of 587 individuals consented, and 298 with PD not yet requiring dopaminergic medication, striatal dopamine transporter deficiency, and serum urate below the population median concentration (<5.8 mg/dL) were randomized between August 2016 and December 2017 at 58 US sites, and were followed up through June 2019. Interventions: Inosine, dosed by blinded titration to increase serum urate concentrations to 7.1-8.0 mg/dL (n = 149) or matching placebo (n = 149) for up to 2 years. Main Outcomes and Measures: The primary outcome was rate of change in the Movement Disorder Society Unified Parkinson Disease Rating Scale (MDS-UPDRS; parts I-III) total score (range, 0-236; higher scores indicate greater disability; minimum clinically important difference of 6.3 points) prior to dopaminergic drug therapy initiation. Secondary outcomes included serum urate to measure target engagement, adverse events to measure safety, and 29 efficacy measures of disability, quality of life, cognition, mood, autonomic function, and striatal dopamine transporter binding as a biomarker of neuronal integrity. Results: Based on a prespecified interim futility analysis, the study closed early, with 273 (92%) of the randomized participants (49% women; mean age, 63 years) completing the study. Clinical progression rates were not significantly different between participants randomized to inosine (MDS-UPDRS score, 11.1 [95% CI, 9.7-12.6] points per year) and placebo (MDS-UPDRS score, 9.9 [95% CI, 8.4-11.3] points per year; difference, 1.26 [95% CI, -0.59 to 3.11] points per year; P = .18). Sustained elevation of serum urate by 2.03 mg/dL (from a baseline level of 4.6 mg/dL; 44% increase) occurred in the inosine group vs a 0.01-mg/dL change in serum urate in the placebo group (difference, 2.02 mg/dL [95% CI, 1.85-2.19 mg/dL]; P<.001). There were no significant differences for secondary efficacy outcomes including dopamine transporter binding loss. Participants randomized to inosine, compared with placebo, experienced fewer serious adverse events (7.4 vs 13.1 per 100 patient-years) but more kidney stones (7.0 vs 1.4 stones per 100 patient-years). Conclusions and Relevance: Among patients recently diagnosed as having PD, treatment with inosine, compared with placebo, did not result in a significant difference in the rate of clinical disease progression. The findings do not support the use of inosine as a treatment for early PD. Trial Registration: ClinicalTrials.gov Identifier: NCT02642393.

Randomized pilot trial for the efficacy of the MMF07 foot massager and heat therapy for restless legs syndrome.

BACKGROUND: Restless Legs Syndrome (RLS) is a sensorimotor condition with a wide range of severity. Symptoms negatively affect sleep and quality of life. Pharmacologic options are not universally effective and side effects are common. Objective data regarding non-pharmacologic treatment is limited. The study objective was to evaluate the efficacy of the MMF07 foot massager and heat therapy on the severity of RLS symptoms. METHODS: In this pilot randomized controlled trial, twenty-eight patients with diagnosed, bothersome RLS were randomized to four treatment arms: no active intervention (n = 7), foot massager (n = 8), heat therapy (n = 6), and foot massager plus heat therapy (n = 7). Participants completed the RLS Severity Scale, RLS Quality of Life questionnaire, and the Medical Outcomes Study Sleep scale at the baseline visit and at the 4-week follow up visit. RESULTS: Four weeks post randomization, participants in the massager group had significant improvement in the RLS severity score (average difference: -9.0, 95% CI: -16.3, -1.7, p = 0.017) and sleep scale (average difference: -22.0, 95% CI: -36.5, -7.5, p = 0.005) compared to the no intervention group. The heat alone group had a significant improvement in the sleep scale compared to the no-intervention group (average difference: -17.4, 95% CI: -32.5, -2.3, p = 0.026). Quality of life improved in the massage only group compared to control (average difference 25.3, 95% CI: -2.4, 53.0, p = 0.072). CONCLUSIONS: Results suggest that the MMF07 foot massage device and heat therapy may be feasible and effective treatment options to improve RSL symptoms.

Motor performance differentiates individuals with Lewy body dementia, Parkinson's and Alzheimer's disease.

INTRODUCTION: Differential diagnosis of dementia with Lewy bodies (DLB), Parkinson's disease with dementia (PDD), Parkinson's disease (PD) and Alzheimer's disease (AD) is challenging. Comparative motor profiles of these neurodegenerative disorders may aid in earlier diagnosis but have not been extensively studied. METHODS: Groups were rigorously matched by age, education, and sex. DLB/PDD participants were matched by Mini-Mental State Examination Score to individuals with AD and by Unified Parkinson's Disease Rating Scale motor scores to individuals with PD. Gait, balance, dual task walking and hand dexterity measures were compared between a combined group (n=21) of individuals with Lewy body dementia (LBD) consisting of those with DLB (n=11) and PDD (n=10) to individuals with PD (n=21) or AD (n=21). RESULTS: Individuals at the same disease stage with LBD walked significantly slower with shorter stride lengths (p<0.05), demonstrated poorer balance on both the Tinetti and Berg Balance Scale, and poorer performance on dual-task and figure-of-eight walking compared to PD and AD (p<0.05 for all) groups. Upper extremity coordination on the 9-hole peg test differentiated LBD from both PD and AD and was the only motor test in which individuals with AD performed worse than those with PD. Tinetti balance subscores were significantly lower in PDD compared to DLB participants (10.4±2.3 versus 12.8±2.3; p=0.027). CONCLUSIONS: Motor features distinguish individuals with LBD from those with AD and PD. Measures of gait, balance and finger dexterity provide an additional means of differentiating individuals with LBD from those with AD and PD.

Paired Studies Comparing Clinical Profiles of Lewy Body Dementia with Alzheimer's and Parkinson's Diseases.

Limited data compares clinical profiles of Lewy Body Dementia (LBD) with Alzheimer's disease (AD) and Parkinson's disease (PD). Twenty-one mildly demented ambulatory LBD subjects were individually matched by MMSE score with 21 AD subjects and by UPDRS motor score with 21 PD subjects. Matched by age, gender, education, and race, pairs were compared using cognitive, functional, behavioral, and motor measures. LBD group performed worse than PD on axial motor, gait, and balance measures. AD had more amnesia and orientation impairments, but less executive and visuospatial deficits than LBD subjects. LBD group had more sleepiness, cognitive/behavioral fluctuations, hallucinations, and sleep apnea than AD or PD. Axial motor, gait, and balance disturbances correlated with executive, visuospatial, and global cognition deficits. LBD is differentiated from AD and PD by retrieval memory, visuospatial, and executive deficits; axial motor, gait and balance impairments; sleepiness, cognitive/behavioral fluctuations, hallucinations, and sleep apnea.

Disease-Modifying Drugs in Parkinson's Disease.

Despite an increased understanding of the pathogenesis of Parkinson's disease (PD), and a number of drugs designed to ameliorate symptoms, finding an effective neuroprotective therapy remains elusive. For decades now, several promising agents targeting different pathways have been explored as potential treatments that could help slow disease progression, but these have met with limited success. There are hurdles to overcome, particularly given that there is no exact animal model of PD and also no reliable biomarkers for PD. Without biomarkers, it is not possible to demonstrate, in the context of a clinical trial, that an intervention prevents neuronal degeneration. However, given the compelling scientific rationale of several compounds, an unrelenting pursuit continues. There have been hundreds of human studies looking at neuroprotection in PD. This article will briefly summarize several of the neuroprotective treatments that have been evaluated in large clinical trials, and will also outline some of the newer therapies that are currently being explored.

Istradefylline for the treatment of Parkinson's disease.

INTRODUCTION: Despite several available therapeutic options to treat the symptoms of Parkinson's disease (PD), there are currently no agents that halt or slow the progression of disease. Istradefylline is a selective adenosine A(2A) antagonist that is currently of interest for the treatment of motor complications in PD. AREAS COVERED: This paper reviews the limitations of currently available treatment options and discusses the results seen in both animal models and human clinical trials that have explored the benefits of istradefylline in PD. EXPERT OPINION: The studies outlined continue to suggest that istradefylline may be a promising non-dopaminergic therapy for the treatment of PD. It has not been proven to be more efficacious than other currently available dopaminergic drugs, nor has it been shown to be of significant benefit as monotherapy; however, it seems to be a safe and well-tolerated drug that may help with wearing-off fluctuations. Istradefylline is not yet an FDA-approved drug. At this time, the potential for approval in the US or through the European Medical Agency remains unknown.

Dopamine-induced nonmotor symptoms of Parkinson's disease.

Nonmotor symptoms of Parkinson's disease (PD) may emerge secondary to the underlying pathogenesis of the disease, while others are recognized side effects of treatment. Inevitably, there is an overlap as the disease advances and patients require higher dosages and more complex medical regimens. The non-motor symptoms that emerge secondary to dopaminergic therapy encompass several domains, including neuropsychiatric, autonomic, and sleep. These are detailed in the paper. Neuropsychiatric complications include hallucinations and psychosis. In addition, compulsive behaviors, such as pathological gambling, hypersexuality, shopping, binge eating, and punding, have been shown to have a clear association with dopaminergic medications. Dopamine dysregulation syndrome (DDS) is a compulsive behavior that is typically viewed through the lens of addiction, with patients needing escalating dosages of dopamine replacement therapy. Treatment side effects on the autonomic system include nausea, orthostatic hypotension, and constipation. Sleep disturbances include fragmented sleep, nighttime sleep problems, daytime sleepiness, and sleep attacks. Recognizing the non-motor symptoms that can arise specifically from dopamine therapy is useful to help optimize treatment regimens for this complex disease.

Non-motor symptoms in Parkinson's disease.

Parkinson's disease is a hypokinetic movement disorder with cardinal motor features of bradykinesia, resting tremor and rigidity. However, non-motor symptoms, such as cognitive, neuropsychiatric, sleep, autonomic and sensory disturbances are gaining increasing attention. These non-motor symptoms may be intrinsic to the disease pathology or may be results of treatment with dopaminergic agents. Given that most, if not all, patients with Parkinson's disease will experience non-motor symptoms, it is important to be sensitive to these phenomena, especially since some non-motor signs may precede motor impairment. Treatment may include interventions independent of traditional, dopaminergic anti-Parkinson therapy or may be tailored to increase or reduce dopamine responsiveness of the symptom.