Infantile spasms in Down syndrome: a good response to vitamin B6

Abstract

We report the results of patients with Down syndrome (DS) and West syndrome (WS) treated with vitamin B6 and discuss the mechanisms of pyridoxine in WS. Twenty patients with DS and WS were referred to our service for infantile spasms (IS) between February 1990 and December 2002. WS was diagnosed on the basis of clinical and electroencephalogram features. Thirteen patients were treated conservately while seven patients (four girls and three boy) were treated according to the new alternative treatment scheme with vitamine B6. The dose of oral pyridoxine was between 200 and 400 mg/day (25–50 mg/kg/day). Five patients initiated the treatment with vitamin B6 for IS two weeks and two patients four weeks after starting to receive antiepileptic drugs. One of them, who initially received intravenous pyridoxine 200 mg/day during three days with a partial control of IS, responded well to oral vitamin B6 400 mg/day associated to valproic acid five months later. Mean age at the beginning of pyridoxine treatment was 9.5 months, ranging from 3 to 14 months. The time between the onset of spasms and vitamin B6 administration ranged from 2 to 4 weeks. Cessation of spasms was obtained within 2 weeks of treatment in four patients. Their electroencephalograms became normal as soon as the spasms disappeared. In four patients whose spasms ceased, pyridoxine was discontinued after 24 and 30 months and clinical spasms did not recur. These four children did not experienceany other type of seizure after a mean time of follow-up of 6 years (range 1–10 years) without any type of treatment. In the fifth patient, cessation of spasms was obtained within four weeks the second time she received vitamin B6, five months after the first treatment. She still receives with pyridoxine 400 mg/day (40 mg/kg/day) after twelve months of follow up and has had no spasms since. Two patients did not respond well either to pyridoxine or to vigabatrin, adrenocorticotropic hormone, valproic acid or benzodiazepines. The patients had no adverse events during treatment with pyridoxine. We consider an oral dose of 200–400 mg/day (25–50 mg/kg/day) of pyridoxine either in monotherapy or combined with classic antiepleptic drugs to be the first choice of therapy in patients with IS and DS. Furthermore, patients who initially do not respond well to pyridoxine could be treated again and for a longer period. (J Pediatr Neurol 2004; 2(1): 15–19)

Keywords

Down syndrome - infantile spasms - pyridoxine - vitamin B6 - West syndrome