Abstracts

Rationale: Electrical Status Epilepticus of Sleep (ESES) is an electrographic pattern with continuous, diffuse, 1.5-3 Hertz spike wave activity during slow wave sleep. ESES is associated with focal or generalized epilepsy, neurocognitive impairment, acquired aphasia (Landau-Kleffner syndrome), visual agnosia, epileptic dysgraphia, progressive prosopagnosia, or motor impairments with ataxia or dyspraxia. The abundance of spike activity required for the diagnosis, what “continuous” means, involvement of slow wave sleep, whether it is an epiphenomenon have been controversial. However, using spike activity diffusely (ESES) or focally (Electrical Epilepsia Partialis Continua of Sleep: EEPCS) in more than 50% of slow wave sleep, we analyze patients with respect to their initial presentation, presence of lesions, and compare the differences in etiology and response to treatment. Methods: We retrospectively analyzed and compared the clinical and electrophysiological properties of 11 ESES and 13 EEPCS patients with motor, cognitive, speech, and visual problems related to the cortical region involved. Results: We studied 13 EEPCS/focal ESES patients with ages ranging between 3 and 19. 11 patients had ESES, and 1 patient who initially presented with generalized ESES transformed to an EEPCS pattern upon treatment. At least 10 patients (41.6%) had language decline/aphasia, and 7 had LKS or its variants (29.1%). 6 (25%) of the EEPCS patients had underlying Rolandic/epilepsy with central temporal spikes. 11 patients (45.8%) had positive MRI abnormalities. Among these 6 (25%) had EEPCS, and5 (20.8%) had ESES. 2 lesional patients had hippocampal volume loss suggesting mesial temporal slerosis. 5 of 6 EECPS patients responded to treatment with a broad-spectrum spike suppressor (VPA, LEV), wheras 1of the 6 patients (16.6%) had response to the combination of OXC and PHT. On the other hand, 2 (28.5%) of the 7 responding ESES patients had sustained response to high dose diazepam in association with broad-spectrum spike suppressors (VPA, LEV, LTG). 5 (72.4%) of the responding ESES patients were treated with variable combinations of VPA, LEV, LTG, PB, TPM, LZP, CLN, IVIG, prednisone, ETZ, ACZ, and pyridoxine. Using combined broad spectrum spike suppressors or other anticonvulsants did not change the faith of nonresponders in ESES and EEPCS groups. However, 2 of the 7 nonresponding EEPCS patients had transient response to diazepam, whereas 3 of 4 (75%) nonresponder ESES patients had transient response to diazepam. MRI abnormalities were associated with relatively poor response to treatment. Conclusions: Comparison of patients with ESES and EEPCS reveals a positive correlation with abnormal MRI findings and unresponsiveness to treatment. In the ESES cohort this is more striking. Treatment with either broad spectrum AEDs, high dose diazepam, or steroids seem to be more effective modalities.