Frontal lobe function in progressive supranuclear palsy
J. Grafman, I. Litvan, C. Gomez and T. N. Chase
Cognitive Neuroscience Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892.
Performance on tasks evaluating "executive and attentional" processes
presumably subserved by prefrontal cortex were compared in patients with
progressive supranuclear palsy and with age- and education-matched control
subjects. The results indicated that patients with progressive supranuclear
palsy were particularly impaired when a task required sequential movements,
conceptual shifting, monitoring the frequency with which stimuli are
presented, or rapid retrieval of verbal knowledge. These deficits could not
simply be accounted for by slowed information processing or by a deficit in
representational knowledge. Conceivably, "weak activation" of frontal lobe
representational knowledge characterized by an observed attentional deficit
results in the neuropsychological impairments noted in patients with
progressive supranuclear palsy. The oral administration of physostigmine,
under double-blind placebo-controlled conditions, did not facilitate
executive or attentional performance as evaluated by our tasks.
