EEG Abnormalities in Children with Speech and Language Impairment.

Abstract

Epilepsy, a chronic condition of recurrent seizures, affects language, but the extent and nature of the language disturbance varies widely according to the type, severity, and cause of the epilepsy. There is paucity of literature on the electroencephalographic abnormalities in children with speech and language impairment. The present study was therefore planned to find the association of epileptiform EEG abnormalities in children with speech and language impairment and if present, their localization and lateralization to the language areas of the brain that are present predominantly in the left hemisphere. The study was conducted on Paediatric patients having speech and language impairment (n=94, age-2 to 8 years) selected on the basis of detailed history and neurologic examination. Video Electroencephalography (EEG) was performed as per American Clinical Neurophysiology Society guidelines using 16 channel RMS computerized EEG machine for a minimum of 40 minutes to capture both wakefulness and sleep along with activation procedures like hyperventilation (if feasible) and photic stimulation. EEG was reviewed for any abnormal EEG background, benign variants, interictal epileptiform discharges and ictal discharges. In our cohort, 19.7% boys and 22.2% girls presented with seizures in their infancy and this gender difference was found to be statistically significant (p<0.05). EEG was abnormal in 47.9% children (45 out of 94) with no significant gender difference. Epileptiform EEG was seen in 73.6% of children with history of seizures and 41.3% of children without history of seizures (p<0.05). The EEG abnormities included: abnormal background (64.5%), presence of generalized interictal epileptiform discharges (57.8%), focal epileptiform discharges (20%) exclusively from left hemisphere and multifocal interictal epileptiform discharges (33.3%), each occurring in isolation or associated with other abnormities. In the current study, it is definite that presence of generalized abnormalities in EEG are seen in higher frequency and focal interictal epileptiform discharges are solely seen in left hemisphere in children with speech and language impairment. Although, there is no distinct pattern of EEG abnormalities in such patients, we recommend a routine EEG in them and also brain imaging to complement the EEG findings.