Idiopathic Hemiconvulsion Hemiplegia Epilepsy in an Eight-Year-Old Boy! Is It the Time to Revisit the HHE Definition?

Abstract

AbstractIdiopathic hemiconvulsion hemiplegia epilepsy (IHHE) syndrome is characterized by the combination of unilateral convulsive status epilepticus, mainly clonic, followed by transient or permanent ipsilateral hemiplegia. It occurs in infants during the course of a nonspecific febrile illness, mainly in the first 2 years of life and in any case before the age of 4 years. Most studies have mentioned that disease occurs in children younger than 4 years. The exact cause of unilateral involvement is not clear. Occurrence of this condition beyond 4 years of age has rarely been described. We report here a previously healthy 8-year-old boy who presented with right hemiclonic seizures for almost 2 weeks occurring along with nonspecific viral illness. He had residual right hemiparesis and his magnetic resonance imaging (MRI) of the brain showed left hemispheric cortical edema with diffusion restriction. The workup for neuroinfections, mitochondriopathy, and MR angiography was negative. The child improved with injection methyl prednisolone pulse therapy along with multiple intravenous and oral antiseizure medications. This case report suggests that IHHE can also occur beyond 4 years of age, and there is a need to revise the diagnostic criteria of IHHE.