Beware of nonconvulsive seizures in prolonged disorders of consciousness: Long-term EEG monitoring is the key

Abstract

ObjectiveEvaluate the prevalence of epileptic seizures (ES) and epileptiform discharges (EDs) in patients with prolonged disorders of consciousness (DOC), and potential influence of amantadine on epilepsy. MethodsWe conducted a retrospective study in 34 patients hospitalized in a DOC care unit for prolonged DOC between 2012 and 2018, who received a long-term EEG monitoring (LTM). We reviewed the prevalence of ES, EDs and nonconvulsive seizures (NCSz), the type of DOC recovery treatment administered, and neurological outcome. ResultsLTM was more effective than standard EEGs in detecting EDs (32% vs 21% respectively). Moreover, 12% of the LTM showed NCSz. Among patients with EDs in LTM, 73% showed no EDs in standard EEG recordings, even when performed more than once. The presence of EDs and/or NCSz in LTM was significantly associated with the occurrence of remote clinical epileptic seizures (p = 0.017) but did not influence neurological outcome (p = 1). Amantadine was not associated with higher occurrence of EDs/NCSz or clinical seizures. ConclusionIn our prolonged DOC population, LTM showed more pathological results (EDs and NCSz) than standard EEGs, which was significantly associated with remote clinical seizures. SignificanceThe use of LTM might be advised to rule out NCSz in patients with prolonged DOC.