Alternating Hemiplegia of Childhood: Pharmacological treatment of 30 Italian patients

Background Alternating Hemiplegia of Childhood (AHC) is a severe disorder. Several drugs have been administered as prophylaxis for paroxysmal attacks, however, no therapy is completely effective. Methods Our aim is to review the pharmacological data related to the prophylactic and acute treatment of a cohort of 30 patients (16 M, 14 F, age range 5–42 years) and to correlate them with the clinical and genetic data collected through the Italian Biobank and Clinical Registry for AHC. Results Flunarizine was the most commonly used long-term treatment in the cohort; it reduced duration and frequency of attacks in 50% of patients and decreased intensity in 32.1%. In younger patients, flunarizine seemed significantly more effective in reducing intensity. We found no correlation between the effectiveness of flunarizine and genotype, or between developmental outcome and duration of treatment. In particular, 3 of our patients affected by E815K mutation presented rapid neurological deterioration despite ongoing treatment. Among the other administered prophylactic therapies, few proved to be effective (benzodiazepines, niaprazine, acetazolamide, melatonin, olanzapine, ketogenic diet). No clear rationale exists regarding their use, but these therapies may work by reducing the triggering factors. Conclusions The presented data are retrospective, but they are aimed at filling a gap given the rarity of the disease and the lack of randomized and controlled studies. Besides their usefulness in clarifying the pathophysiology of the disease, prospective studies involving larger cohorts of ATP1A3 mutated AHC patients are needed to provide a rationale for testing other molecules.