Selectively impaired reaction time in Parkinson's disease: Persistent absence of simple reaction advantage in a patient with frontal complications

The search for specific patterns of impaired reaction time in Parkinson's d isease has yielded conflicting results. We propose subtypes that exhibit di fferent patterns of impairment and report the case of a patient, Jobe, whos e simple and binary choice reaction times were tested repeatedly in a varie ty of stimulus-response paradigms over a period of 4 years. Jobe consistent ly failed to exhibit the normal simple reaction advantage even though his c hoice reaction times fell well within the normal range. While his general i ntellectual status was above average, he had great difficulty with some neu ropsychological tests. He was seldom able to acquire a new category in the Wisconsin Card Sort Test and also had difficulty with the Tower of London T est. We ascribe Jobe's selective impairment of simple reactions to an inabi lity to engage in the off-line preparatory processing that confers an advan tage on simple reactions.