INTRAVENOUS LEVODOPA IN HALLUCINATING PARKINSONS-DISEASE PATIENTS - HIGH-DOSE CHALLENGE DOES NOT PRECIPITATE HALLUCINATIONS

In five nondemented Parkinson's disease patients with daily visual hal lucinations, we tested whether high-dose TV levodopa (LD) infusions pr ecipitated hallucinations. Two infusion paradigms were studied, each w ith 1.5-mg/kg hourly dose for 4 hours-steady infusion and pulse infusi on of the full hour dose over 5 minutes each hour. In both protocols, plasma LD levels changed significantly during the infusion protocol. T he cumulative area under the curve was equivalent for the two infusion s. All patients remained alert, and none developed visual hallucinatio ns. The two patients with peak-dose dyskinesias on oral LD developed p rominent dyskinesias during the infusion. Visual hallucinations do not relate simply to high levels of LD or to sudden changes in plasma lev els.