Ictal fear depends on the cerebral laterality of the epileptic activity.

Glascher and Adolph (2003) proposed that both amydalae are specialized for fear, but that the right one is a fast, short, and relatively automatic fear processor, whereas the left one is more detail-oriented and perceptual-cognitive. According to this model, early ictal fear should occur more often in cases with a right temporal lobe epileptic focus. Several authors have tried to find a hemispheric specialization for ictal fear, but have not reached the power to attain a statistically significant effect of focus side. In this study, using previously published cases of unilateral epileptic focus causing early ictal symptoms of fear, we found 144 cases, of which 98 had a right hemisphere focus (68%) and 46 having left hemisphere focus (32%, p < 0.0005). Several control variables were assembled to verify possible alternative explanations of the main effect.