Early Onset Hemiparesis with Epilepsy: Pattern of Surgical Outcome according to Ictal Onset Zone

Kim, Kwang Ki; Kim, Dong Wook; Lee, Sang Kun; Lee, Seo Young; Kim, Joo Yong

Abstract

PURPOSE: To reveal the pattern of surgical outcome according to the location of ictal onset zone in the patients who had a history of early onset (less than two years old) hemiparesis and delayed epilepsy. Many children with acute infantile hemiplegia (AIH) develop delayed epilepsy. This can lead to HHE (Hemiplegia, hemiconvulsion, and epilepsy) syndrome. Epilepsy patients associated with AIH or HHE syndrome generally have been thought to be medically intractable and difficult to treat surgically.
METHODS
Patients with a history of early onset hemiparesis with epilepsy who had undergone surgical treatment from November 1995 to May 2002 at Seoul National University Comprehensive Epilepsy Center were recruited. Diagnostic criteria include convulsions, followed by a flaccid hemiplegia, and later epilepsy with partial seizures. Multidisciplinary presurgical evaluations were performed which include a complete neurological examination, brain MRI, long-term video-EEG monitoring, FDG-PET, intracarotid amobarbital test, and ictal and interictal SPECT if possible. Patients with epileptogenic zone outside the hippocampus underwent implantation of intracranial electrodes. The surgical side was localized by the clinical, neuroimaging, and electrophysiological results includeing results of invasive studies. Anterior temporal lobectomy (ATL), cortical resection, functional hemispherectomy, and callosotomy were performed according to the results of presurgical evaluation.
RESULTS
Twenty-five patients were included. Mean age was 29.8 ranging from 19 to 60 years old. Fifteen were male and 10 were female. All had a previous history of febrile convulsions. The onset age of febrile convulsion and hemiplegia was one to 48 months (mean=18.0+/-13.2) and the onset age of epileptic seizures were 0.5 to 40 years (mean=9.9+/-8.2). Seventeen of them were right-handed, eight were left-handed and one was bilateral-handed. Follow-up periods after surgery were one to eleven years (mean=5.6+/-2.2). Twelve patients were diagnosed as medial TLE and underwent ATL. The other thirteen patients were diagnosed as neocortical or multifocal epilepsy. Eleven of medial TLE patients were seizure free after ATL and only one had aura. However, only four patients with neocortical epilepsy were seizure free and nine were not. Surgical outcome was significantly different between ATL only and other surgical procedures (p=0.004).
CONCLUSION
In patients of early onset hemiparesis with epilepsy, various ictal onset zones can be possible. The medial TLE patients diagnosed by comprehensive presurgical evaluation, in spite of hemiatrophy on brain MRI, showed a good surgical outcome. Surgical treatment should be considered for the selected patients.