Clinical predictors of driving status in Huntington's disease.

The aim of this study was to identify the motor, cognitive, and behavioral determinants of driving status and risk factors for driving cessation in Huntington's disease (HD). Seventy-four patients with HD were evaluated for cognitive, motor, psychiatric, and functional status using a standardized battery (Unified Huntington's Disease Rating Scale [UHDRS] and supplemental neuropsychological testing) during a research clinic visit. Chart review was used to categorize patients into two driving status categories: (1) "currently driving" included those driving and driving but with clinician recommendation to restrict, and (2) "not driving" included those with clinician recommendation to cease driving and those not currently driving because of HD. Multi- and univariate logistic regression was used to identify significant clinical predictors of those driving versus not driving. Global cognitive performance and UHDRS Total Functional Capacity scores provided the best predictive model of driving cessation (Nagelkerke R(2) = 0.65; P < 0.0001). Measures of learning (P = 0.006) and psychomotor speed/attention (P = 0.003) accounted for the overall cognitive finding. In univariate analyses, numerous cognitive, motor, and daily functioning items were significantly associated with driving. Although driving status is associated with many aspects of the disease, results suggest that the strongest association is with cognitive performance. A detailed cognitive evaluation is an important component of multidisciplinary clinical assessment in patients with HD who are driving.