Susceptibility to neuroleptic-induced parkinsonism - age and increased substantia nigra echogenicity as putative risk factors

Objective. - Patients treated by neuroleptics often develop neuroleptic-induced parkinsonism (NIP) to a varying extent. The reasons for this are discussed controversially in the literature. Previous transcranial sonography (TCS) findings of the substantia nigra (SN) in patients with idiopathic Parkinson's disease suggest a correlation of echogenicity with nigrostriatal dysfunction. Method. - One hundred psychiatric patients receiving neuroleptics were included. They underwent clinical examination for NIP (Simpson and An us-scale) and, independently, TCS of the SN. History of smoking habits and medication were taken from the patient's chart. Results. - We found a significant positive association of the prevalence of NIP with age (P < 0.01) and the echogenic area of the SN (P < 0.05). Neither type nor dosage of the neuroleptics was found to have any significant impact on the occurrence of NIP. Smokers displayed lower prevalence of NIP (P < 0.05) and lower EPS scores (P < 0.0 1). Conclusions. - These findings suggest that age and increased size of SN echogenicity are possible risk factors for NIP. In contrast, smoking seems to have a certain protecting effect. 41 (C) 2003 Editions scientifiques et medicales Elsevier SAS. All rights reserved.