West syndrome and other infantile epileptic encephalopathies--Indian hospital experience

Abstract

Children with infantile epileptic encephalopathies comprising 3.5% of the Pediatric Neurology Clinic registrations in a tertiary care hospital were retrospectively analyzed. Data were retrieved from case records and analyzed for seizure semiology, prenatal and perinatal insults, developmental status and relevant investigations. The various therapeutic modalities and their influence on spasm frequency, long-term development and final seizure status were compared. The two primary outcome variables analyzed included final seizure status and developmental outcome. Of the 94 infantile epileptic encephalopathies, West syndrome was the commonest (55.3%), of which two thirds were symptomatic. Etiological factors were prenatal in 66.6% and perinatal in 33.3%. The initial response to ACTH was good in 54.5% with subsequent relapse in 27.8% and for prednisolone was 52.9 and 44.4%, respectively, compared to 25.3% spasms control with conventional antiepileptic drugs. Disease category of infantile epileptic encephalopathies evolved in 4, i.e. early myoclonic encephalopathy to West syndrome 1, early infantile epileptic encephalopathy to West syndrome 1, West syndrome to Lennox-Gastaut syndrome 2. Psychomotor retardation was seen in 88.2%, with 16.1% having normal development at onset of spasms. Microcephaly was associated with delayed development but did not influence final seizure outcome. Final seizure outcome was poor in children with delayed development at onset (adjusted odds ratio [OR] = 4), delay in diagnosis >12 months (OR = 2.27) and in children with Lennox-Gastaut syndrome (OR = 4.75). ACTH/prednisolone and antiepileptic treatment versus antiepileptics alone showed a good final seizure response in 36.6% versus 20%. Development on follow up was delayed in children with initial psychomotor retardation (OR = 23.4) and abnormal electroencephalogram (OR = 7.46). Perinatal factors constituted one third of symptomatic West syndrome. The use of ACTH/corticosteroids resulted in good initial spasm control though final seizure outcome and development were unaffected. Prednisolone had similar response to ACTH in spasm control but higher subsequent relapse rate. Vigabatrin was useful though often unaffordable. The identification of a neurometabolic etiology, though uncommon, has significant therapy implications. Delay in diagnosis was common and negatively influenced final seizure outcome.