Hemiconvulsion-hemiplegia-epilepsy (HHE) syndrome with neonatal onset-a rare and atypical occurrence

Introduction: The hemiconvulsion-hemiplegia-epilepsy (HHE) syndrome was described by Gastaut (1960) as predominantly unilateral convulsive seizures of long duration followed by hemiplegia and focal epilepsy. The peak incidence has been observed between 5 months and 2 years. We present a child with an unusual early onset HHE syndrome in the first week of life.

Case report: A 5-day-old boy born at term (38 weeks of gestation, birth-weight 3195g, APGAR 7/8/10, vacuum extraction because of pathological cardiotocogram) was transferred to our hospital with prolonged left focal and generalized seizures of undetermined duration (probably >24 hours), fever was not observed. Seizures stopped with standard dosis of phenobarbital and phenytoin. On initial interictal EEG right hemispheric depressed activity with rhythmic theta discharges was seen. Cerebrospinal fluid (CSF) showed 612/µl red blood cells, 12/µl white blood cells with normal glucose, protein and lactate, bacterial culture was negative. CSF PCR for enterovirus and mycoplasma hominis DNA was negative. Metabolic investigations (aminoacids and organic acids in urine, acylcarnitine, lactate and ammonia in blood) and serological tests in maternal blood (cytomegalovirus, parvovirus B19, rubella virus, varicella virus and toxoplasma gondii) were normal. An initial cranial MRI done at the age of 6 days showed edematous swelling of the right hemisphere and a small right cerebellar hemorrhage. MRI at the age of 3 weeks and 7 months revealed marked right hemispheric cortical atrophy sparing basal ganglia and thalamus. Clinically the boy developed left side hemiplegia and microcephaly, no seizures occurred under phenobarbital so far despite right focal sharp wave activity in the EEG.

Discussion: Hemiatrophia cerebri after prolonged seizures is described in classical HHE syndrome. Neonatal onset is atypical and has to our knowledge so far not been described. We present clinical data and early MRI imaging.