Flunarizine-induced parkinsonism in the elderly

Twenty-seven patients (19 women and 8 men, ages 63 to 88 years; mean, 74 years) displayed mild to moderate parkinsonism and altered ballistic motor performances during long-term flunarizine treatment. One month after, flunarizine withdrawal, 20 patients showed clear-cut improvements in both clinical features and ballistic motor performances; a complete recovery within 6 months was observed in all these patients but one, who still showed very mild slowness of movement. On the other hand, seven patients showed little clinical improvement and still maintained markedly altered ballistic motor performances 1 month after drug withdrawal. At the 2-month follow-up assessments, either they did not improve further or they deteriorated; they were successfully treated with L-dopa and, despite the ameliorations, after 12 to 24 months they still have definite parkinsonian syndrome. The authors conclude that (1) flunarizine, even at the recommended dose (10 mg daily), can induce reversible parkinsonism, at least in subjects older than 60; (2) the persistence of a marked symptomatology 2 months after flunarizine withdrawal should lead to starting treatment with antiparkinsonism drugs; (3) the study of ballistic movements is proposed as a useful tool for objective quantification and early detection of bradykinesia.