Prevalence of benign epileptiform variants observed in an EEG laboratory from South India

Abstract

No study has investigated the prevalence and pattern of benign epileptiform variants (BEVs) in the electroencephalograph (EEG) of subjects from a developing nation. We addressed this issue by ascertaining the BEVs among subjects referred for EEG to a comprehensive epilepsy program in South India. We identified BEVs in 326 out of 1778 subjects (18.3%) who had both awake and sleep EEG recordings. The frequency distribution of individual BEVs were as follows: benign sporadic sleep spikes 8.2%, wicket waves 1%, 14 and 6 Hz positive spikes 5.7%, 6 Hz spike-waves 2.8% and rhythmic temporal theta burst of drowsiness 0.8%. We conclude that the prevalence rates of BEVs among South Indian subjects are not different from those reported from developed countries. We have highlighted the consequences of misinterpretation of BEVs as epileptiform, which is more likely to occur in Third World countries because of the non-availability of qualified technologists and electroencephalographers.