Related Experiment Video
Updated: May 3, 2026

Driving Simulation in the Clinic: Testing Visual Exploratory Behavior in Daily Life Activities in Patients with Visual Field Defects
Published on: September 18, 2012
On-road driving impairments in Huntington disease
Hannes Devos1, Alice Nieuwboer, Wim Vandenberghe
1From the Department of Physical Therapy (H.D.), College of Allied Health Sciences, Georgia Regents University, Augusta, GA; Department of Rehabilitation Sciences (H.D., A.N., W.D.W.), KU Leuven, Heverlee; Department of Neurology (W.V.), University Hospitals Leuven; Department of Neurosciences (W.V.), KU Leuven, Leuven; CARA Department (M.T.), Belgian Road Safety Institute, Brussels, Belgium; Department of Neurology (E.Y.U.), University of Iowa, Iowa City; and Neurology Service (E.Y.U.), Veterans Affairs Medical Center, Iowa City, IA.
Objective:
To determine the driving skill impairments and underlying visual, motor, and cognitive deficits that lead to failure on road testing in manifest Huntington disease (HD).
Methods:
Certified driving assessment experts scored performance on 13 specific on-road driving skills in 30 persons with HD and 30 controls and issued a pass/fail decision based on their overall impression. These on-road skill items were mapped onto an existing theoretical framework that categorized driving skills into operational, tactical, visuo-integrative, and mixed clusters. The HD group additionally completed a detailed off-road battery of motor, visual, and neuropsychological tests.
Results:
The HD group performed worse on all on-road items. Fourteen drivers with HD (47%) failed the road test compared with none of the controls. Scores on the Total Functional Capacity scale discriminated significantly between pass and fail groups. Total on-road score and performance in operational, tactical, and visuo-integrative clusters correlated strongly (Spearman ρ >0.50) with the pass/fail decision. The off-road tests showed variable strengths of association depending on the level of driving skill. Selective attention was strongly associated (Spearman ρ >0.50) with the total on-road score and all driving clusters.
Conclusions:
HD affects driving at many levels due to motor and cognitive deficits and leads to unsafe road performance even in mild stages. The high failure rate on the road test and difficulties in all aspects of on-road driving suggest that monitoring of fitness to drive should be initiated in the early course of HD.
Related Concept Videos
Huntington Disease l: Introduction
Parkinson Disease ll: Pathophysiology
Parkinson's Disease: Overview
Parkinson Disease l: Introduction
Parkinson's Disease: Treatment
Parkinson's Disease is primarily a result of the loss of dopaminergic neurons in the substantia nigra pars compacta. The cornerstone of...
Alzheimer Disease ll: Pathophysiology

