Abstracts

Rationale: To summarize the clinical, electrophysiological, neuroradiological, and histological findings of 34 patients with Rasmussen encephalitis (RE) and to evaluate the surgical outcome. Methods: Thirty-four patients were screened out by criteria of RE. All patients underwent MRI more than 2 times. Interictal/ictal scalp electroencephalography (EEG) was recorded using a video-EEG monitoring system, with electrodes placed according to the international 10-20 system for all patients. The duration of video-EEG monitoring ranged from 1-3 days, and at least 3 habitual seizures were recorded. Preoperative and postoperative neuropsychological tests were administered and assessed by a psychologist. Surgery were conducted in the left hemisphere in 13 patients and in the right hemisphere in 21 patients. The mean age at surgery was 7.90±4.92 years. Surgical methods included anatomical hemispherectomies (AH, 9 cases), functional hemispherectomies (FH, 17 cases), hemispherotomy (6 cases), bipolar electro-coagulations of functional cortexes (BEFC, 1 case), and selective resection guided by intracranial electrode monitoring (1 case). Surgical treatment and presurgical evaluation including semiology, magnetic resonance imaging (MRI) and video-electroencephalography (VEEG) were analyzed retrospectively. Results: MRI before surgery treatment discovered unihemispheric focal cortical atrophy and T2/FLAIR hyperintense signals in 33 cases and bilateral hemispheric atrophy in 1 case. All of the patients had undergone simple partial seizure, 30 patients had EPC. The mean follow-up period was 4.35 years (range 2-8 years). After surgery, 27 patients (79.4%) were evaluated as being Engel Class I, 1 patient as Engel Class II, 3 patients as Engel Class III (had a significant decrease in seizure frequency) , and 3 patients as Engel Class IV (had no change in seizure frequency ). One patient presented contralateral seizure after AH and was diagnosed with bilateral RE. All of the patients except the one with bilateral RE had increases in cognitive abilities after the surgery. The mean intelligence quotient (IQ) prior to surgery was 73.34 ± 6.61, but increased to 78.96 ± 5.54 (P＜0.01) at the time of postoperative assessment. In addition, most of them could walk independently after surgery, but fine movement of the hands was lost. The main early complication was aseptic meningitis (35%) after hemispherectomy and hemispherotomy. Postoperative hydrocephalus was observed in 2 patients after AH and 1 patient after FH, and there were no death in this series. Conclusions: Hemispherectomy and hemispherotomy were both confirmed as beneficial procedures in controlling seizures and improving quality of the life in cases with RE.