Abstracts

Rationale: Epilepsy surgery has been reported to be successful in children with refractory epilepsy caused by congenital or early-acquired brain lesions, regardless of generalized or contralateral EEG findings (Neurology 2007; 69: 389). We report two cases of refractory epilepsy with cerebral hemiatrophy and predominant-contralateral EEG findings, in which functional hemispherectomy was effective to control seizures. Methods: We investigated EEG, MRI, SPECT and clinical charts of two epileptic patients with cerebral hemiatrophy and predominant-contralateral EEG findings in our hospital. Results: Case 1: A 5-year-1-month-old girl was admitted to our hospital for pre-surgical evaluation. She had incomplete paresis of right extremities and severe mental retardation due to porencephaly after congenital left middle cerebral artery infarction. From age 1-year-7-month, she had refractory tonic seizures with right arm predominant tonic component. MRI showed left porencephaly corresponding to left middle cerebral artery area. Interictal discharges showed right-predominant diffuse spikes and waves and independently left frontal sharp waves. Ictal discharges showed right-predominant diffuse fast wave bursts. The first ictal SPECT showed hyperperfusion in left occipital region and the second depicted hyperperfusion in left frontal region. Left functional hemispherectomy was performed at 5-year-4-month of age. She remained seizure-free for 18 months thereafter. Right-predominant diffuse spikes and waves on EEG disappeared, and right incomplete paresis was unchanged. Case 2: A 3-year-8-month-old boy was admitted to our hospital for pre-surgical evaluation. He had incomplete paresis of right extremities and mild mental retardation after septic meningitis due to H. influenzae at 1-year-7-month of age. From age 2-year-2-month, he developed right-predominant tonic seizure. MRI FLAIR image showed left cerebral hemiatrophy with hyperintense signals. Interictal discharges showed right-predominant diffuse spikes and waves. Ictal discharges showed right-predominant diffuse fast wave bursts followed by diffuse rhythmic spikes and waves. Ictal SPECT was performed twice; hyperperfusion area was (1) left basal ganglia and insular cortex and (2) left frontal region, each. Left functional hemispherectomy was performed at 4-year-1-month of age. He remained seizure-free for 15 months thereafter. Right-predominant diffuse spikes and waves on EEG disappeared. Right incomplete paresis was worsened transiently but improved soon afterwards. Conclusions: Cerebral hemiatrophic lesion can cause functional disability and epileptic seizures, and interictal discharges and ictal discharges may be contralateral. Ictal SPECT findings were effective to confirm the epileptogenic side.