Epileptogenesis: left or right hemisphere dominance? Preliminary findings in a hospital-based population

The aim of this study was to determine if there is cerebral cortical hemispheral asymmetry in human epileptogenesis. We studied 75 epilepsy patients using electroencephalograms, neuroimaging, ictal semiology and physical examination to determine if epilepsy originates more frequently from the left or the right hemisphere. We considered epilepsy to be definitely-lateralized if one or more of these was abnormal unilaterally and there were no contradictory findings. Twenty-seven of the patients had lateralized epilepsy: 20 from the left hemisphere and seven from the right hemisphere (P< 0.05). These findings from our hospital-based ambulatory patient population suggest that the left hemisphere is more epileptogenic than the right. Further study of lateralization of epileptogenesis in a community population-based sample of incident new-onset cases seems warranted.