Electroencephalography Patterns and Prognosis in Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: The prognostic significance of interictal epileptiform discharges (IED) and periodic patterns (PP) after ischemic stroke has not been assessed. We sought to test whether IED and PP, detected on standard Electroencephalography (EEG) performed during the acute phase of ischemic stroke are associated with a worse functional outcome. METHODS: One-hundred-fifty-seven patients 18 years or older with a diagnosis of acute ischemic stroke presenting within 72 h from stroke onset were prospectively enrolled and followed. Patients with a pre-stroke history of seizures or epilepsy, previous debilitating neurological disease or conditions that precluded the performance of EEG were excluded. Interpretation was performed by a blinded board certified neurophysiologist. IED and PP (grouped as epileptiform activity [EA]) were defined according to proposed guidelines. Univariable and multivariable analyses were used to identify predictors of outcome (modified Rankin Scale dichotomized ≤2 vs. ≥3) at 3 months. RESULTS: In the univariable analysis, admission NIHSS (OR 1.20, 95% CI 1.12-1.28, p = 0.001), age (OR 1.03, 95% CI 1.01-1.05, p = 0.02), and presence of EA (OR 2.94, 95% CI 1.51-5.88, p = 0.001) were significantly associated with the outcome at 3 months. In the multivariable analysis, only admission NIHSS (OR 1.19, 95% CI 1.11-1.28, p < 0.001) and the presence of EA (OR 2.27, 95% CI 1.04-5.00, p = 0.04) were independently associated with the prognosis. SIGNIFICANCE: The importance of EEG in the prognosis of acute ischemic stroke warrants additional research, examining the role of medication therapy on the outcome and the occurrence of seizures for those patients with specific EEG patterns.

The impact of EEG in the diagnosis and management of patients with acute impairment of consciousness.

OBJECTIVES: To assess the frequency of electroencephalogram (EEG) requests in the emergency room (ER) and intensive care unit (ICU) for patients with impairment of consciousness (IC) and its impact in the diagnosis and management. METHODS: We followed patients who underwent routine EEG from ER and ICU with IC until discharge or death. RESULTS: During the study, 1679 EEGs were performed, with 149 (8.9%) from ER and ICU. We included 65 patients and 94 EEGs to analyze. Epileptiform activity was present in 42 (44.7%). EEG results changed clinical management in 72.2% of patients. The main reason for EEG requisition was unexplained IC, representing 36.3% of all EEGs analyzed. Eleven (33%) of these had epileptiform activity. CONCLUSION: EEG is underused in the acute setting. The frequency of epileptiform activity was high in patients with unexplained IC. EEG was helpful in confirming or ruling out the suspected initial diagnosis and changing medical management in 72% of patients.

The impact of EEG in the diagnosis and management of patients with acute impairment of consciousness / Impacto do EEG no diagnóstico e conduta dos pacientes com alteração aguda do estado da consciência

OBJECTIVES: To assess the frequency of electroencephalogram (EEG) requests in the emergency room (ER) and intensive care unit (ICU) for patients with impairment of consciousness (IC) and its impact in the diagnosis and management. METHODS: We followed patients who underwent routine EEG from ER and ICU with IC until discharge or death. RESULTS: During the study, 1679 EEGs were performed, with 149 (8.9 percent) from ER and ICU. We included 65 patients and 94 EEGs to analyze. Epileptiform activity was present in 42 (44.7 percent). EEG results changed clinical management in 72.2 percent of patients. The main reason for EEG requisition was unexplained IC, representing 36.3 percent of all EEGs analyzed. Eleven (33 percent) of these had epileptiform activity. CONCLUSION: EEG is underused in the acute setting. The frequency of epileptiform activity was high in patients with unexplained IC. EEG was helpful in confirming or ruling out the suspected initial diagnosis and changing medical management in 72 percent of patients.

OBJETIVO: Avaliar a frequência de exames de eletroencefalograma (EEG) solicitados no pronto-socorro (PS) e na unidade de terapia intensiva (UTI) em pacientes com rebaixamento do nível de consciência, bem como seu impacto no diagnóstico e na conduta. MÉTODOS: Acompanhamos pacientes submetidos ao EEG do PS e da UTI com rebaixamento do nível de consciência até a alta ou óbito. RESULTADOS: Realizamos 1679 EEGs no período de estudo; destes, 149 (8,9 por cento) foram solicitados no PS e na UTI. Incluímos 65 pacientes e 94 EEGs para análise; destes, 42 (44,7 por cento) apresentavam atividade epileptiforme. O EEG mudou a conduta em 72 por cento dos pacientes. A razão principal para solicitação do EEG foi rebaixamento do nível de consciência de origem inexplicável (36,3 por cento dos EEGs). Destes, 33 por cento tinham atividade epileptiforme. CONCLUSÃO: Embora o EEG seja pouco usado em condições agudas, a frequência de atividade epileptiforme foi alta nos pacientes com rebaixamento do nível de consciência de origem inexplicável. O EEG foi decisivo para o esclarecimento diagnóstico e implicou mudança da conduta em 72 por cento dos pacientes.