Idiopathic Hemiconvulsion Hemiplegia Epilepsy (IHHE) in an 8 yr old boy

Idiopathic Hemiconvulsion Hemiplegia Epilepsy (IHHE) syndrome is characterised 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 less 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 here report a previously healthy eight-year old boy who presented with right hemi-clonic seizures for almost 2 weeks occurring along with non-specific viral illness. He had residual right hemiparesis and his MRI brain showed left hemispheric cortical oedema with diffusion restriction. The work up for neuroinfections, mitochondriopathy, MR angiography was negative. The child improved with inj. Methyl prednisolone pulse therapy along with multiple intravenous and oral anti-seizure medications. This case support suggests that IHHE can occur beyond 4 years of age also and there is a need to revise the diagnostic criteria of IHHE.
Keywords: Idiopathic hemiconvulsion hemiplegia epilepsy syndrome, childhood, status epilepticus