Abstracts

Rationale: Hemimegalencephaly (HME) is a rare malformation of cortical development. HME prevalence of 1-3 cases/1000 epileptic children. It accounts for 30 - 50% of patient who underwent hemispherectomy. Through the series of patient we have will be able to outline the demographic data, clinical features, and management including the outcome of surgical treatment. Methods: Restrospective chart review of 24 patient with (HME) identified from Epilepsy Registry in King Faisal Specialist Hospital and Research Centre between 2004 and 2016. The following information was collected; age, sex, underlying cause, developmental ability and cognitive function, seizure types, types of surgery and outcome (seizure free and seizure persist). Results: Gender and age, 13 were young male age 0-3, 11 were young females age 0-8 with a total mean of age 20 days. 11 out of 24 patients 45.8% were diagnosed with Right Hemimegalencephaly while 13 out of 24 patients 54% were diagnosed with Left Hemimegalencephaly. Male tend to have left hemisphere more than right and female have more right hemisphere affected than left. There was no underlying cause identified in 10 patients 41%, 14 patients had associated condition; neurocutaneous syndrome identified in 11 patients 45% one patient had congenital CMV, one had Goldenhar syndrome, and one unknown syndrome. Several seizures were reported focal, focal > GTC, EPC, myoclonic and infantile spasm in the 24 patients. Cognitive dysfunction was common; Global developmental delay occur in 18 patient 75%, mild mental retardation in 5 and only one had normal development. Three patients had focal resection; 2 temporal and 1 frontal resection, 20 patients had functional hemispherectomy and 2 patient had no surgery. Outcome for surgery. (Table 1)  Seizure response to functional hemispherectomy differ according to type of seizures. (Table 2) Conclusions: Hemimegalencephaly although is rare cortical malformation but not in children with intractable epilepsy. The clinical picture in HME dominated by severe and drug resistant epilepsy. Neurocutaneous disorder is an important underlying cause or associated condition in Hemimegalencephaly account for 42% in our series with Epidermal Nevus the most common type. Cognitive dysfunction is a common sequel of HME with 75% of our patient have global developmental delay. Focal resection or anticonvulsant will not lead to seizure freedom in most of cases. Functional Hemispherectomy is treatment of choice with high rate of seizure freedom. Funding: No Funding