Memory and psychomotor impairment following high-dose interferon treatment in amyotrophic lateral sclerosis.

Patients with amyotrophic lateral sclerosis were treated with high-dose intravenous infusion of human leukocyte interferon for six days. Neuropsychological examinations were carried out before, during and after the treatment. Marked reversible dysfunction was detected in immediate memory functions, coordination of hand movements, and drawing. Motor perseveration, micrographia, and slowing of behaviour were also observed. Changes appeared four to 12 days after start of treatment, with the peak on days six to eight. Recovery was almost complete by day 15. Intellectual ability, as measured by three WAIS subtests, praxis of hand movements, visuognostic functions, speech, reading, writing, and calculation remained essentially unaffected. The profile of the neuropsychological deficits observed, the absence of defects typical of focal posterior cortical lesions, the simultaneously slowed electroencephalographic activity with frontal accentuation, and the increased central conduction times of brain stem auditory evoked potentials suggest frontobasal involvement.