Migrating Partial Seizures in Infancy: Expanding the Phenotype of a Rare Seizure Syndrome

Abstract

The constellation of early-onset, unprovoked, alternating electroclinical seizures and neurodevelopmental devastation was first described by Coppola et al. We report six new patients and the prospect of a more optimistic developmental outcome. Retrospective chart reviews were performed on six infants evaluated at the Children's Hospital of Philadelphia (five patients) and at Hershey Medical Center (one patient) who had electroclinically alternating seizures before age 6 months of age. Electroclinical characteristics and long-term follow-up were recorded. All had unprovoked, early-onset (range, 1 day to 3 months; mean, 25 days) intractable electroclinical seizures that alternated between the two hemispheres. Each patient underwent comprehensive brain imaging and neurometabolic workups, which were unrevealing. In all patients, subsequently intractable partial seizures developed and often a progressive decline of head circumference percentile occurred with age. Three demonstrated severe developmental delay and hypotonia. All survived, and 7-year follow-up on one patient was quite favorable. Our patients satisfied the seven major diagnostic criteria first described by Coppola et al. The prognosis of this rare neonatal-onset epilepsy syndrome from the original description and subsequent case reports was very poor, with 28% mortality, and the majority of survivors were profoundly retarded and nonambulatory. Our patient data validate the diagnostic criteria of this syndrome and further quantify a previously described observation of progressive decline of head circumference percentiles with age. Our data also suggest that the prognosis of this syndrome, although poor, is not as uniformly grim as the cases reported previously in the literature.