Beware of nonconvulsive seizures in prolonged disorders of consciousness: Long-term EEG monitoring is the key. (April 2022)

• Record Type: Journal Article
• Authors: Fierain, A.; Gaspard, N.; Lejeune, N.; El Tahry, R.; Speybroeck, N.; Dermauw, V.; Ferrao Santos, S.
• Is Part Of: Clinical neurophysiology. Volume 136(2022)
• Page Start: 228
• Page End: 234
• Publication Date: 2022-04
• Subjects: Epilepsy -- Epileptic seizure -- Epileptiform discharges -- Coma -- Disorder of consciousness -- Long-term EEG monitoring; Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2021.12.020
• Languages: English
• ISSNs: 1388-2457

Abstract

Highlights: One third of long-term EEG monitoring (LTM) in prolonged disorders of consciousness patients showed epileptic discharges (EDs), either sporadic, rhythmic or periodic patterns. Nonconvulsive seizures (NCSz) were recorded in 12% of patients, of whom only two had a history of clinical seizures. LTM outperformed standard and repeated EEGs for detecting EDs and NCSz. Abstract: Objective: Evaluate 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. Methods: We 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. Results: LTM 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. Conclusion: In our prolonged DOC population, LTM showed more pathological results (EDs and NCSz) than standard EEGs, which was significantly associated with remote clinical seizures. Significance: The use of LTM might be advised to rule out NCSz in patients with prolonged DOC.