Abstract

Two hundred and sixty-five normal individuals and patients with clinical signs of extracranial disease, 174 patients with intracranial disease without signs of basal ganglia involvement and 126 patients with signs of basal ganglia disorders were examined clinically for the occurrence of the activation phenomenon of rigidity, the palmomental reflex and the glabella tap response. A comparison between the three groups, decade for decade, showed that the activation phenomenon was so common in the first two groups that its presence was unlikely to be the first sign of Parkinson's disease. A tendency to increasing frequency with increasing age was noted. The palmomental reflex and glabella tap response were more frequent in the last group, but also so common in the first two, that the clinical significance was marginal. No tendency to increasing occurrence with increasing age was noted.