[Exogenous psychoses in Parkinson syndrome. Frequency and causal conditions].

Exogenous psychotic symptoms of a wide variety have been reported to appear more and more frequently since the introduction of levodopa in the therapy of Parkinson's disease. They were considered to be caused by treatment related imbalance of cerebral neurotransmitters and hypersensitivity of the dopaminergic receptors, respectively. In the present investigation an analysis was done concerning the relevance of different antiparkinsonian drugs and other factors such as severity of neurological and cerebroorganic symptomatology, age, duration of treatment, EEG and brain atrophic changes and additional physical diseases for the appearance of psychotic symptoms. The questions were posed to 152 patients (54 men, 88 women) aged 34-76 years, which received a treatment with levodopa alone, in combination with a decarboxylase inhibitor, amantadines and/or anticholinergics for a period of 1-9 years. An exogenous psychotic symptomatology was observed in 42 patients (27,6%), explicitly under all antiparkinsonistic drugs, but not when amantadines were given as the initial treatment. In patients receiving levodopa/decarboxylase inhibitor psychotic symptoms could be observed most frequently but at the same time the duration of treatment was the longest. In 15 patients psychotic symptoms appeared under different antiparkinsonian drugs. In 28 patients this symptomatology was followed by a constant severe dementia. Predisposing factors for exogenous psychosis proved to be: a higher age at the beginning of the treatment and the initiation of treatment, a pronounced neurological symptomatology and signs of dementia as well as additional physical diseases. Because of the very complex conditions under which exogenous psychosis can be observed and the additional fact that they can appear under each antiparkinsonian substance, levodopa cannot be considered as the sole cause.(ABSTRACT TRUNCATED AT 250 WORDS)