PARKINSONISM AND REST TREMOR SECONDARY TO SUPRATENTORIAL TUMORS SPARING THE BASAL GANGLIA

Intracranial neoplasms are an uncommon cause of symptomatic Parkinsoni sm and rest tremor. We found an incidence of 0.3% in a prospective eva luation of 907 patients with supratentorial tumours. Eight patients wi th Parkinsonism and rest tremor secondary to supratentorial tumours sp aring the basal ganglia are reported. Neuro-imaging revealed compressi on and distortion of the basal ganglia by large tumours which were ide ntified histopathologically as meningiomas in four patients and as an epidermoid, a fibrillary astrocytoma, an anaplastic oligodendroglioma and a glioblastoma. Six patients underwent tumour removal by craniotom y, in two the histopathology was obtained by stereotactic biopsy. Four pa tients were free of Parkinsonian symptoms and signs on long-term f ollow-up. The possible pathophysiological mechanisms involved are disc ussed. Since some of these patients closely resemble cases of idiopath ic Parkinson's disease, and the movement disorder can precede other sy mptoms and signs or will remain isolated in the further course, the di agnosis of an intracranial neoplasm was generally delayed in these pat ients. Increased awareness of this rare entity may lead to an earlier diagnosis. Early computed tomography in patients with Parkinsonism mig ht help to detect these patients with a potentially curable cause of t heir condition.