Objective: To develop a cutaneous biomarker for Parkinson disease (PD).Methods: Twenty patients with PD and 14 age-and sex-matched control subjects underwent examinations, autonomic testing, and skin biopsies at the distal leg, distal thigh, and proximal thigh. a-Synuclein deposition and the density of intraepidermal, sudomotor, and pilomotor nerve fibers were measured. a-Synuclein deposition was normalized to nerve fiber density (the a-synuclein ratio). Results were compared with examination scores and autonomic function testing.Results: Patients with PD had a distal sensory and autonomic neuropathy characterized by loss of intraepidermal and pilomotor fibers (p , 0.05 vs controls, all sites) and morphologic changes to sudomotor nerve fibers. Patients with PD had greater a-synuclein deposition and higher a-synuclein ratios compared with controls within pilomotor nerves and sudomotor nerves (p , 0.01, all sites) but not sensory nerves. Higher a-synuclein ratios correlated with Hoehn and Yahr scores (r 5 0.58-0.71, p , 0.01), with sympathetic adrenergic function (r 5 20.40 to 20.66, p , 0.01), and with parasympathetic function (r 5 20.66 to 20.77, p . 0.01). Conclusions:We conclude that a-synuclein deposition is increased in cutaneous sympathetic adrenergic and sympathetic cholinergic fibers but not sensory fibers of patients with PD. Higher a-synuclein deposition is associated with greater autonomic dysfunction and more advanced PD. These data suggest that measures of a-synuclein deposition in cutaneous autonomic nerves may be a useful biomarker in patients with PD. Accumulating evidence suggests that a-synuclein deposition occurs early in the course of PD and may antedate the appearance of the clinical features of the disease.2 This has provided the rationale for the use of a-synuclein as a biomarker in PD. 3Skin punch biopsy could provide a simple means to measure a-synuclein deposition in the peripheral nervous system; however, preliminary studies used techniques optimized for CNS tissue, relied on small tissue volumes, and did not systematically study autonomic substructures, and therefore detected a-synuclein in only a minority of subjects with PD. [4][5][6][7][8] We recently reported novel methods to study the cutaneous autonomic innervation in skin biopsies of patients with peripheral nerve disease.9,10 We hypothesized, based on the prominent autonomic manifestations of PD, that a-synuclein deposition would be elevated in cutaneous structures with autonomic innervation.The aims of the study were to determine 1) whether a-synuclein was present in cutaneous sensory and autonomic nerves, 2) the relationship between cutaneous a-synuclein deposition and *These authors contributed equally to this work.

Introduction The Parkinson's disease questionnaire-39 (PDQ-39) is a common measure of health related quality of life (HRQoL) that is widely used with Parkinson disease (PD) patients. Previous evidence suggests that the PDQ-39 reflects at least 8 dimensions (i.e., Emotion, Cognitions, Mobility, etc). To date, little research has examined the external/convergent validity of the Cognitions and Emotional Well-being domains of the PDQ-39. Methods A convenience sample of 303 PD patients underwent a comprehensive multi-domain neuropsychological evaluation, including tests of execution function, episodic verbal memory, processing speed, language and working memory, as well as completing measures of depression, apathy, state and trait anxiety and HRQoL (PDQ-39). Hierarchical regressions were conducted in order to examine the relationship between scores on neuropsychological tests and the Cognitions index, as well as mood measures and the Emotional Well-being index of the PDQ-39. Results Neuropsychological test performance did not account for a significant amount of variance in the PDQ-39 Cognitions index scores. Instead, it was depression that significantly contributed to the Cognitions index, above and beyond neuropsychological performance. The PDQ-39 Emotional Well-being index was also related to mood measures, primarily depression and trait anxiety. Conclusions The PDQ-39 Cognition index may be more related to mood functioning, as opposed to cognitive functioning, and should not be considered a “proxy” for cognitive functioning. Future studies are needed to better explain the construct of this index.

Due to controversy regarding the influence of apathy on quality of life (QoL), the authors examined the independent influence of apathy, depression, and trait anxiety in a nondemented sample of patients with Parkinson disease (PD). Participants (N=107) completed standard self-report measures of QoL and mood/motivation. Analyses investigated the contribution of these measures and empirically derived factor scores on QoL. QoL was predicted by trait anxiety, dysphoria, and decreased interest, with no independent contribution of apathy. Different patterns emerged with respect to domain-specific QoL, with trait anxiety being the strongest predictor across most domains. Anxiety was most widely related to QoL in PD, with minimal contribution of apathy. Future studies should examine different roles of PD mood/motivation symptoms on caregiver QoL.

Objective Studies with healthy elderly adults suggest apathy, depression and anxiety are more common among individuals with mild cognitive impairment (MCI). We examined differences in mood/amotivational symptoms among Parkinson’s patients with and without MCI. Methods Parkinson patients (N=214) underwent neurocognitive evaluations including assessment of apathy (Apathy Scale; AS), depression (Beck Depression Inventory-II; BDI-II) and trait anxiety (State-Trait Anxiety Inventory-Trait scale; STAI-T). Results Trait anxiety and depression were more severe in PDs with MCI. Delineation of MCI into amnestic vs non-amnestic subtypes revealed greater depression, apathy and anxiety among amnestic MCI relative to cognitively-intact PD patients. Conclusion Parkinson patients with MCI report greater mood symptoms compared to Parkinson patients who are cognitively intact.