Journal of Parkinson’s Disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease, and it is characterized by a complex variety of both motor and neuropsychiatric issues. Effective treatment of PD symptoms requires a combination of pharmacotherapy and allied health therapies; however, treatment is generally monodisciplinary, with the neurologist referring out to varied therapists as needed. In order to more effectively manage PD as it progresses over time, clinics are beginning to implement and advocate the use of more integrative models of care for PD. In order to understand the effectiveness of these models, a comprehensive literature review was conducted through electronic searches of PubMed, Academic Search Premier, PsycINFO, Health Source: Nursing/Academic Edition, AgeLine, AMED (Alternative Medicine), Health and Psychosocial Instruments, Health Source - Consumer Edition, and Social Work Abstracts databases. The review identified only two published studies, both of which only evaluated the effectiveness of multidisciplinary care in outpatient settings. The results of the studies indicated that multidisciplinary treatment led to marked improvement in patient outcomes; however, these results are limited as they measured short term outcomes only. The limited available evidence on the efficacy of integrative healthcare delivery models in PD should serve as a call-to-action for clinicians to work to improve the care, and subsequently the quality of life, of PD patients through streamlining PD-specialized care with multiple complementary clinicians and incorporating patient preferences and goals into treatment.

The diagnosis of Parkinson's disease (PD) is solely based on movement disorders, but several non-motor deficits are common in PD. Depression often precedes the movement dysfunctions and continues to be a major concern during all stages of the disease. The pathophysiology of parkinsonian depression is largely unknown, but appears to partly differ from depression in patients without PD. Because of the increased awareness of the negative impact of depression on the quality of life of PD patients, there is a growing interest in developing animal models of parkinsonism that also recapitulate the depressive-like symptomatology. This review introduces paradigms for measurement of depression-like behaviors in rodents and summarizes data on behavioral, neurochemical and pharmacological changes in experimental PD models with relevance for depression-related states.

The transplantation of dopamine-rich tissue into the putamen of patients with Parkinson's disease shows much potential for use as a therapeutic strategy. However, a number of grafted individuals subsequently developed a set of abnormal involuntary movements (AIMs), unrelated to the dyskinesia caused by L-DOPA treatment, which have been termed graft-induced dyskinesia. Given the small number of patients, pre-clinical modeling of graft-induced dyskinesia in animal models will be critical to determine the underlying mechanisms and amelioration potential of this technique. Here we show that abnormal involuntary movements of the limbs, trunk and face can be observed in transplanted hemi-parkinsonian mice following amphetamine administration, similar to those previously described to model graft-induced dyskinesias in rats. C57Bl6 and CD1 mice were first rendered hemi-parkinsonian with 6-hydroxydopamine, treated with L-DOPA for 21 days until dyskinetic, and then transplanted with a single cell suspension of embryonic ventral mesencephalon (VM E12.5) tissue from corresponding strains into the denervated striatum. At 16 weeks post-transplantation, a single injection of amphetamine-elicited dyskinesia in a subgroup of mice of both strains, behavioural pattern not observed pre-transplantation. The number of surviving dopaminergic cells in the graft did not differ between those that developed AIMs and those that did not. The movements were phenotypically comparable to those seen in the rat model and parallels can be drawn to the human form of the movements, although the mouse model maybe less reproducible than the rat equivalent. This mouse model will facilitate assessment of graft-induced dyskinesia with mouse-derived stem cell lines and exploration of mechanisms using transgenic mice in future studies.

Oxidative stress and oxidized dopamine contribute to the degeneration of the nigrostriatal pathway in Parkinson's disease (PD). Selenoproteins are a family of proteins containing the element selenium in the form of the amino acid selenocysteine, and many of these proteins have antioxidant functions. We recently reported changes in expression of the selenoprotein, phospholipid hydroperoxide glutathione peroxidase GPX4 and its co-localization with neuromelanin in PD brain. To further understand the changes in GPX4 in PD, we examine here the expression of the selenium transport protein selenoprotein P (Sepp1) in postmortem Parkinson's brain tissue. Sepp1 in midbrain was expressed in neurons of the substantia nigra (SN), and expression was concentrated within the centers of Lewy bodies, the pathological hallmark of PD. As with GPX4, Sepp1 expression was significantly reduced in SN from PD subjects compared with controls, but increased relative to cell density. In putamen, Sepp1 was found in cell bodies and in dopaminergic axons and terminals, although levels of Sepp1 were not altered in PD subjects compared to controls. Expression levels of Sepp1 and GPX4 correlated strongly in the putamen of control subjects but not in the putamen of PD subjects. These findings indicate a role for Sepp1 in the nigrostriatal pathway, and suggest that local release of Sepp1 in striatum may be important for signaling and/or synthesis of other selenoproteins such as GPX4.

Introduction: Motor imagery during functional magnetic resonance imaging is commonly used to understand the neural underpinnings of complex movements. This approach has recently been applied to individuals with Parkinson disease (PD) to better understand how brain function may relate to movement dysfunction. However, the ability of individuals with PD to imagine movements when “Off” dopamine replacement medication is poorly understood. Therefore, the primary purpose of the current study is to test the ability of people with PD to imagine movements while “On” and “Off” anti-Parkinson medication. Methods: Vividness of imagery was assessed in 28 individuals with mild to moderate PD (Hoehn and Yahr stages 1–3) via the Kinesthetic Visual Imagery Questionnaire (KVIQ-20) both “On” and “Off” anti-Parkinson medication. Vividness of imagery of 32 age-matched older adults was also assessed. Results: No differences in vividness of imagery were observed between “Off” and “On” medication states (p = 0.15). Imagery was similar between controls and PD both “Off” (p = 0.25) and “On” (p = 0.46) anti-Parkinson medication. A significant correlation was observed between imagery and disease severity while “On” anti-Parkinson medication (r = −0.49; p = 0.008). Discussion and conclusions: Vividness of movement imagery was not different between “Off” and “On” anti-Parkinson medications or between PD and controls. These results suggest that people with PD are able to imagine similarly to older adults both when “On” and “Off” anti-Parkinson medication, and supports the use of motor imagery in the “Off” medication state.

Parkinson's disease (PD) is the second most common neurodegenerative disorder. It is generally defined by its progressive motor features; but increased attention is being paid to its non-motor neuropsychiatric symptoms, which profoundly impact quality of life for patients and caregivers. Anxiety and depression are particularly problematic and are the strongest predictors of quality of life in PD. Recent research has focused on non-pharmacological approaches to treating depression and anxiety in patients with PD. Cognitive-behavioral therapy (CBT) is a potentially efficacious non-pharmacological treatment for mood and anxiety symptoms associated with PD. Accordingly, this review examines empirical studies of CBT-based treatments for depression and anxiety symptoms in PD. Medical Subject Headings were used in searches of PsychInfo and PubMed of English-language articles published in peer-reviewed journals, resulting in the identification of 10 articles. Four additional articles were identified from the references of these articles and upon the suggestions of experts, for 15 articles in all. Results of individual studies varied significantly; however, the randomized controlled trials showed encouraging results and support the need for further investigation of the utility of CBT for depressed and anxious patients with PD. CBT is potentially a useful treatment for patients with PD and comorbid depression and/or anxiety, but more systematic research will be necessary to measure its effects.

We sought to assess the quality of life in PD patients before the diagnosis, in comparison to age-matched individuals free of PD, among participants in two large prospective cohorts of men and women. Components of the Short-Form Health Status Survey (SF36) were administered to all participants in 1996 and 2008 in the Health Professionals Follow-up Study (HPFS), and in 1992, 1996, 2000 and 2004 in the Nurses' Health Study (NHS). We used scores in 7 health-related quality of life-dimensions, that were rated from 1(worst) to 100(best) points. We fitted a multivariate mixed-effect model with repeated measures to estimate the expected decline with age and compared that to the decline observed among PD cases by time to diagnosis. 454 men and 414 women with PD contributed data to the analyses. A decline in physical function in PD patients relative to the whole cohort began approximately 7.5 years prior to diagnosis in women and 3 years prior to diagnosis in men, and continued to decline thereafter with a rate of 2.35 and 1.43 points per year in women and men respectively (p < 0.001 for both). For comparison, the average yearly decline in individuals without PD was 0.42 and 0.23 points per year in women and men respectively. Other measures of quality of life (only available in women) declined in a similar pattern to physical function. In summary, the quality of life in PD patients begins to decline years before the diagnosis.

Apathy, an intrinsic disorder of motivation, can manifest in cognitive, affective, and behavioral domains. Recent attempts to formalize diagnostic criteria for apathy have advocated this triadic structure. The Apathy Scale (AS) is the only recommended measure for assessing apathy in Parkinson's disease (PD) by a Movement Disorders task force. We tested the hypothesis that the AS distinctly measures the three proposed domains of apathy in PD. Participants were 226 non-demented PD patients. Apathy Scale data were examined with exploratory factor analysis (EFA). The three factor solution resembled the triadic structure of cognitive, behavioral, and affective domains; however, adjustments to the AS may be appropriate.

Some patients with Parkinson's disease (PD) reportedly experience ‘sleep benefit’: an improved motor functioning upon awaking in the morning. In this questionnaire study, 114 out of 243 consecutive outpatients with PD (46.9%) subjectively experienced sleep benefit. Among those patients that regularly took an afternoon nap, 33.7% experienced sleep benefit after the nap as well. Between patients with and without sleep benefit, there were no differences in demographic or clinical variables, including age, disease duration, dopaminergic treatment, and nocturnal sleep quality. Sleep benefit remains an intriguing but elusive phenomenon, which deserves renewed attention and further research.

Pathological studies have shown that Parkinson's disease (PD) at early stages affects the olfactory bulb (OB) followed by an involvement of substantia nigra (SN) and other brain regions. Emerging imaging methodologies detect alterations in certain brain regions of living PD patients, which may support proper diagnosis and monitor disease progression. Here we used a novel approach of diffusion tensor imaging (DTI), taking advantage of the technique's inherent diffusion directional information, for region of interest (ROI) placement and diffusion measurements in the OB and SN. 16 healthy individuals and 18 early-moderate patients with PD, supported by reduced ¹²³I-Ioflupane putaminal binding, were examined with two identical DTI series. Olfaction was assessed with the 40-item UPSIT and Parkinsonian severity with UPDRS and Hoehn&Yahr. DTI measurements showed reduced fractional anisotropy (FA) for SN in the PD group in both DTI series. In OBs there was reduced FA in the PD group in the first series, but not in the second. As OBs are located in an area susceptible to artifacts, the coefficient of variation between the two DTI series was higher than for other brain regions. The UPSIT scores were much lower in the PD group than in healthy individuals. In conclusion, we describe a novel approach for more objective ROI placement in DTI, which enabled us to detect altered diffusion in the SN and OBs in PD. These data provides further support that diffusion MRI can be of high clinical utility as a biomarker to facilitate diagnosis and follow disease progression in PD.