Abstracts

Rationale: Diagnosis criteria of Encephalopathy with Electrical Status Epilepticus during Sleep (EESES)/ECSWS are still a matter of discussion, as the course of the epilepsy and the underlying conditions are different. The diagnosis may be evident for structural EESES with acute behavioral or cognitive regression or for Landau-Kleffner syndrome. However the boarders with Atypical Rolandic Epilepsy (ARE) are sometimes hazy, as the EEG aspect may be similar in both situations, but it may only be transient in ARE without cognitive deterioration. We still need to find a cut off for prognosis information and pharmacologic strategies. We present here two observations of ARE evolving to EESES with detailed longitudinal neuropsychological and neurophysiological study.Methods: Our patients affected with ARE or EESES/ECSWS are followed every 6 months (or less) with a clinical and neuropsychological assessment (memory, verbal skills, executive skills, nonverbal skills, and an annual Wechsler scale), and a whole-night sleep video- EEG. In order to answer to this question, we selected two patients with non structural EESES preceded by ARE, followed from the beginning of the epilepsy until their recovery. We analyzed separately their clinical, neuropsychological and neurophysiological data longitudinally, and tried to evidence correlations.Results: In both patients, the neuropsychological or motor deterioration was closely correlated to the localization of the main slow focus, and to an increase of EEG spike and waves (SW) amplitude and amount, with a rhythmic bisynchronisation, to the appearance of negative ictal symptoms ( symptomatic SW ), and to a strong sleep SW activation, with the disappearance of slow sleep organization. Their cognitive and behavioral recovery was correlated to the decrease of SW and the reappearance of sleep organization. Conclusions: EESES may be preceded by, but is different than ARE. The evolution to EESES is a dynamic process and the diagnosis sometimes necessitates several months of following with regular clinical cognitive and sleep EEG assessments. We propose here some qualitative electroclinical criteria of EESES, which need to be confirmed in larger cohorts.