Driving and visuospatial performance in people with hemianopia

Practical fitness to drive was studied in 28 patients with homonymous hemianopia (HH). More specifically, visual performance during driving and neuropsychological visuospatial test performance were compared and related. Visuospatial tests were a priori classified in four visuospatial sets, and were evaluated on three measures, namely lateralisation, speed, and accuracy. Driving safety and fluency was assessed by means of a practical test-ride and scored using a structured protocol. It was concluded that HH cannot be considered a definite contraindication for holding a drivers' licence since not all patients failed the test-ride. The most frequent remark made by the driving expert was a lack of stability in steering: It was found that visual performance during driving was significantly related to visuospatial test performance, operationally defined as a function of typical visual HH disability. A specific combination of the lateralisation, speed and accuracy measures of the visuospatial sets explained 77% of the variance in visual performance during driving. For deciding which type of mobility rehabilitation goal is feasible in HH, our results suggested administering the Grey Scales task, the Trailmaking test, the Bells test and a Hidden Figures test.