Emergence of nonmotor symptoms as the focus of research and treatment of Parkinson's disease: Introduction to the special section on nonmotor dysfunctions in Parkinson's disease

Parkinson's disease (PD) is traditionally characterized by the cardinal motor symptoms of tremor, rigidity, slowness of movement, and impairments of posture, gait, and balance. A relatively new focus of research and treatment is the nonmotor symptoms of the disease, following from recent understanding of the neuropathological stages. Disruptions of arousal, mood, sleep, and autonomic function before the first motor signs of PD implicate the lower brainstem, which is affected before the substantia nigra and dopaminergic system. In later stages of the disease, the pathology extends to the cortex, accompanied by impairments in cognition and perception. The articles in this special section advance our knowledge of the brain bases of the nonmotor symptoms of PD, including disrupted visual perception, impaired cognition across a range of domains, and psychiatric and artistic manifestations. Subtypes under investigation include those described by side of disease onset (left or right body side), predominant cognitive profile, and gender. Taken together, the articles in this special section reflect the field's growing focus on the nonmotor symptoms of PD, their brain bases, and the corresponding potential for their treatment.Published versio

Visual correlates of functional difficulties in Parkinson's disease and Alzheimer's disease

Thesis (Ph.D.)--Boston UniversityAlthough motor dysfunction in Parkinson's disease (PD) and memory deficits in Alzheimer's disease (AD) are the respective hallmark symptoms, both neurodegenerative disorders are also associated with significant disruptions in visual functioning. In PD, visuospatial function is impaired, particularly in patients with left-side onset of motor symptoms (LPD), reflecting pathology in right hemisphere brain regions, including the parietal lobe. LPD visuospatial performance is characterized by perceptual distortions, suggesting that lower-level visual processing may contribute to abnormal performance. In AD and PD, reduced contrast sensitivity and other visual difficulties have the potential to impact everyday functioning. The relation of PD visuospatial problems, and AD and PD contrast sensitivity deficits to higher-order impairments is understudied. The present experiments examined visual and visuospatial difficulties in these groups and evaluated an intervention to improve everyday visual function. Experiment I assessed performance on a line bisection task in PD. Participants included non-demented patients (10 LPD, 10 with right-side motor onset [RPD]) and 11 normal control adults (NC). Performance was related to data from measures of retinal structure (Optical Coherence Tomography) and function (Frequency Doubling Technology; FDT) across the eye. Correlations of structure and function were found for all groups. LPD showed predicted downward bisection bias in some sections of the left visual field. Expected rightward bisection bias in LPD was not consistently seen using this presentation method. For RPD, in some sectors, worse FDT sensitivity correlated with upward line bisection bias, as predicted. Experiment II investigated if performance of a complex, familiar visual search task (bingo) could be enhanced in AD and PD by manipulating the visual components of contrast, size, and visual complexity of task stimuli. Participants were 19 younger adults, 14 AD, 17 PD, and 33 NC. Increased stimulus size and decreased complexity improved performance for all groups. Increasing contrast also benefited the AD patients, presumably by compensating for their contrast sensitivity deficit, which was more severe than in the PD and NC groups. The general finding of improved performance across healthy and afflicted groups suggests the value of visual support as an easy-to-apply intervention to enhance cognitive performance

Is Online Motor Control Really Impaired In Parkinson\u27s Disease?

Patients with Parkinson’s disease (PD) are thought to be selectively impaired in consciously-mediated online automatic motor control, whereas the ability to perform subconscious online adjustments remains intact. This present study evaluates the hypothesis that the previously alleged deficits in online motor control in PD are not due to the consciousness of the correction, but rather are attributable to aspects of the prior experimental designs disproportionately penalizing patients for PD-related bradykinesia. Here, we implemented a modified traditional double-step paradigm to investigate consciously-mediated online motor control in PD, in a manner that would be unconfounded by disease-related bradykinesia. Further, we investigated the effects of dopamine-replacement therapy on performance. We found that PD patients (n=12) and healthy-matched controls (n=12) were equal in performing automatic online corrections whether or not these corrections were consciously perceived, and their performance was unaffected by dopaminergic therapy. These findings inform our understanding of automatic motor control in PD

A Review of Different Applications of Wireless Sensor Network (WSN) in Monitoring Rehabilitation

Parkinson’s disease is a neurodegenerative brain disorder that affects movement. The lack of dopamine in the brain cells causes patients have lesser ability to regulate movement and emotions as time goes on. There is no cure for this disease. Although drug therapies are successful for some patients, most of the patients usually develop motor complications. In this paper, we presented our work towards the comparison of several wireless sensor network (WSN) systems for monitoring Parkinson’s patients. The designs of each system are explored. The parts being considered to design a wireless sensor network and limitations are discussed. These findings helped us to suggest a possible wireless sensor network system to supervise Parkinson’s diseases patients for a more extended period of time

The basal ganglia in perceptual timing: timing performance in Multiple System Atrophy and Huntington's disease.

The timing of perceptual events depends on an anatomically and functionally connected network comprising basal ganglia, cerebellum, pre-frontal cortex and supplementary motor area. Recent studies demonstrate the cerebellum to be involved in absolute, duration-based timing, but not in relative timing based on a regular beat. Conversely, functional involvement of the striatum is observed in relative timing, but its role in absolute timing is unclear. This work tests the specific role of the basal ganglia in the perceptual timing of auditory events. It aims to distinguish the hypothesised unified model of time perception (Teki, Grube, & Griffiths, 2012), in which the striatum is a mandatory component for all timing tasks, from a modular system in which they subserve relative timing, with absolute timing processed by the cerebellum. Test groups comprised individuals with Multiple System Atrophy, a disorder in which similar pathology can produce clinical deficits associated with dysfunction of the cerebellum (MSA-C, n = 8) or striatum (MSA-P, n = 10), and early symptomatic Huntington's disease (HD, n = 14). Individuals with chronic autoimmune peripheral neuropathy (n = 11) acted as controls. Six adaptive tasks were carried out to assess perceptual thresholds for absolute timing through duration discrimination for sub- and supra-second time intervals, and relative timing through the detection of beat-based regularity and irregularity, detection of a delay within an isochronous sequence, and the discrimination of sequences with metrical structure. All three patient groups exhibited impairments in performance in comparison with the control group for all tasks, and severity of impairment was significantly correlated with disease progression. No differences were demonstrated between MSA-C and MSA-P, and the most severe impairments were observed in those with HD. The data support an obligatory role for the basal ganglia in all tested timing tasks, both absolute and relative, as predicted by the unified model. The results are not compatible with models of a brain timing network based upon independent modules

Statins are underused in recent-onset Parkinson's disease with increased vascular risk : findings from the UK Tracking Parkinson's and Oxford Parkinson's Disease Centre (OPDC) discovery cohorts

Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.Peer reviewedPublisher PD