Dysautonomia and REM sleep behavior disorder contributions to progression of Parkinson's disease phenotypes.

Non-motor symptoms of Parkinson's disease (PD) such as dysautonomia and REM sleep behavior disorder (RBD) are recognized to be important prodromal symptoms that may also indicate clinical subtypes of PD with different pathogenesis. Unbiased clustering analyses showed that subjects with dysautonomia and RBD symptoms, as well as early cognitive dysfunction, have faster progression of the disease. Through analysis of the Parkinson's Progression Markers Initiative (PPMI) de novo PD cohort, we tested the hypothesis that symptoms of dysautonomia and RBD, which are readily assessed by standard questionnaires in an ambulatory care setting, may help to independently prognosticate disease progression. Although these two symptoms associate closely, dysautonomia symptoms predict severe progression of motor and non-motor symptoms better than RBD symptoms across the 3-year follow-up period. Autonomic system involvement has not received as much attention and may be important to consider for stratification of subjects for clinical trials and for counseling patients.

Huntington's Disease and Employment: The Relative Contributions of Cognitive and Motor Decline to the Decision to Leave Work.

BACKGROUND: Huntington's disease (HD) presents with motor, cognitive, and behavioral symptoms that impair functional capacity and the ability to maintain employment. The relative contribution of cognitive decline to work disability remains controversial. OBJECTIVE: To evaluate the association of cognitive decline, compared with motor decline, with the decision to leave work. METHODS: Data from the Enroll-HD observational study were analyzed. The correlation of age of cognitive symptom onset and age of motor symptom onset with age at leaving work was assessed. The association of the Stroop Color Naming Test (SCNT) cognitive assessment and the Total Motor Score (TMS) assessment (reverse scored) with the Total Functional Capacity (TFC) assessment was also assessed. RESULTS: For every year delay in cognitive symptom onset, there was a 0.806 year increase in age at leaving work (SE = 0.030, p < 0.001, adj-R2 = 0.628). For every year delay of motor symptom onset, there was a 0.814 year increase in age at leaving work (SE = 0.031, p < 0.001, adj-R2 = 0.603). For every additional correct SCNT response given and for every unit increase in TMS, there was a 0.105 unit increase (SE = 0.006, p < 0.001, adj-R2 = 0.315) and a 0.104 unit decrease in TFC (SE = 0.003, p < 0.001, adj-R2 = 0.640), respectively. CONCLUSIONS: Cognitive symptoms have a significant association, comparable to that of motor symptoms, with occupational functioning and the decision to leave work, suggesting that development of therapies for both cognitive and motor decline would be important for allowing people with HD to remain in the workforce longer.