Psychotic complications of long term levodopa treatment of Parkinson's disease

Psychotic symptoms such as hallucinations, delusions and confusion are well known side-effects of levodopa (LD) therapy of Parkinson's disease (PD), even if there is much confusion regarding the variability of the psychotic manifestations. We studied 18 patients clinically treated with LD associated with an inhibitor of peripheral aminoacid decarboxylase (DI). Daily dosage of LD ranged between 250 and 1750 mg; the mean age of patients was 72.7 years; the age at the onset of the disease was 63.3 and duration of the disease 8.4 years. In all patients any possible etiology of Parkinsonism were excluded. Brain CT scan excluded focal lesions in all cases. Psychotic complications were seen in 8 patients: using DSM-III-R-criteria, the various LD-induced psychotic states can be classified in two groups: simple (including or hallucinations with preserved insight) and complex ones (including chronic confusion without preserved insight). Patients with complex symptoms were younger at the onset of the disease and they developed these symptoms later, and these patients were also more susceptible to dyskinesias developed before psychotic complications