The effects of flunarizine, a calcium-entry blocker, in alternating hemiplegia are reported in the first 12 children included in an international study coordinated from the Dept Pediatrics, University Hospital Gasthuisberg, B-3000 Leuven, Belgium. Cases from France, Italy, Portugal, Spain and Scotland meeting the following diagnostic criteria were included: onset before 18 months, repeated attacks at least 2 per month involving both sides of the body, associated oculomotor abnormalities and autonomic disturbances, and mental and neurological abnormalities. A family history of migraine was present in half the patients. Various auticonvulsants used in 10 patients were without benefit. The dose of flunarizine was 5 mg daily for 4 months. During the open study period, all but one patient had a reduction in frequency and/or duration and severity of attacks, and mental development improved in several. In a subsequent double-blind placebo-controlled withdrawal study lasting another 4 months, 6 patients received placebo, 3 continued flunarizine therapy, and 3 declined inclusion in the controlled trial. Deterioration occurred in 5 of the 6 placebo patients and 2 of the 3 flunarizine treated patients. Relapses were thought to be precipitated by parental anxiety occasioned by the double-blind protocol. Flunarizine was well tolerated except for somnolence and weight gain. The author is soliciting further investigators and patients for a larger, more definitive study. 
COMMENT. The failure of conventional anticonvulsant drugs in the treatment of alternating hemiplegia (AH) is well known. Propanolol (Inderal), of reputed benefit in childhood migraine, was without effect in 2 patients with AH followed personally, and flunarizine treatment observed in a 3-year-old boy had only an equivocal and partial effect.
The pathogenesis of alternating hemiplegia is unknown although a vascular mechanism related to migraine is probable. Calcium channel antogonists such as flunarizine, effective in the treatment of migraine, are vasodilators and prevent the influx of extracellular calcium into vascular smooth muscle . The response of AH to flunarizine is certainly not proven but the results of these preliminary studies are promising.