Spectrum and patterns of EEG Abnormalities in a peripheral outpatient centre in Kenya

Abstract

Background: Electroencephalography (EEG), which records electrical activity in the brain, is a valuable tool for assessing epilepsy and other paroxysmal events. However, despite the high prevalence of epilepsy in Africa, EEG remains underutilised.
Objective: This study aimed to evaluate the indications for and patterns of EEG abnormalities in a busy outpatient neurophysiology laboratory in Kenya.
Methods: This was a retrospective observational, non-interventional study. We abstracted and analysed EEG reports and recordings from 1st June 2021 to 31st December 2023. The sociodemographic data, handedness, reasons for referral, clinical diagnoses, EEG abnormalities, types of epileptiform and non- epileptiform patterns, and EEG diagnoses were encoded and entered into IBM SPSS version 27.
Results: A total of 445 EEGs were carried out during the study period, with males constituting 53.9% of the cases. The majority of patients (40.4%) fell within the 10-19-year age group. Additionally, 59.6% of patients were already receiving anticonvulsant medications. The most common reason for referral was suspected seizure in 34.6% of cases, followed by loss of consciousness without abnormal movement in 32.8% of cases. Among males, abnormal movement suspected to be a seizure was the most frequent presentation, while unconsciousness was the predominant presentation among females. The EEG revealed epileptiform abnormalities in 68.3% of cases, with generalised seizure observed in 48.0% of cases.  Furthermore, 40.6% of subjects in the 10 - 19 year age group showed no abnormalities on the EEG.
Conclusions: The current study underscores the high prevalence of seizure abnormalities in this rural setting, the common reasons for referral, and the demographic features of patients who present for EEG. It highlights the importance of EEG in distinguishing seizure and non-seizure episodes, especially in paediatric and adolescent age groups.