FREQUENCY AND PROGNOSTIC SIGNIFICANCE OF ABNORMAL ELECTROENCEPHALOGRAPHIC FINDINGS IN ACUTE STROKE PATIENTS

Abstract

Electroencephalography (EEG)are useful in detecting changes in neuronal integrity and predicting
outcome in acute stroke. Thus, the study hope to determine the frequency and prognostic importance
of abnormal EEG wave changes in acute stroke. Adult patients with acute stroke who met the
inclusion criteria were studied. Stroke severity, functional outcome was determined using the
National Institutes of Health Stroke Scale (NIHSS) and Modified Rankin scale (MRS) respectively
which were assessed on admission, 72hours, 7days, 14days and 30days after stroke. The proportion of
stroke patients with slow frequencies on EEG was 63.3% compared to 16.2% in controls (p0.008).
The percentage of Alpha wave, Beta wave, Delta wave, Theta wave, and Intermixed wave
respectively among cases were 24.1%, 12.7%, 22.8%, 21.52%, and 18.9% respectively compared to
66.3%, 17.5%, 5.0%, 3.8%, and 7.5% respectively among the controls (p0.008). The percentage of
epileptiform discharges seen among stroke patients was 31.6% compared to 11.2% in controls.
Epileptiform discharge was seen 31.6%, 62.7%, 57.9%, and 44.4% respectively at presentation, day
3, day 7, day 14, and day 30 respectively in stroke patients. Presence of sharps, RAWOD, asymmetry
and slowing respectively at day 14 (p0.014, 0.03, 0.02, 0.014) and at day 30 (p0.049, 0.03, 0.07, 0.034)
were associated with poor outcome among those with NIHSS >20. Among stroke patients with
NIHSS >20, there was association between good outcome and occurrence of Alpha rhythm within two
weeks of acute stroke. EEGwaves changes are useful in predicting functional outcome in acute stroke.