Hemispheric specialization in partial epilepsy role of dichotic listening cv task and central audiological evaluation in the neuropsychological assessment

Abstract

We studied 49 patients with partial epilepsy divided into lesional cases (i.e. with lesions on CT scan) and non-lesional cases (i.e. without CT scan lesions), in relation to the Wechsler Intelligence Scale subtests (Coding, Digit span), dichotic listening CV task and Central Auditory Test (SSI, PSI). The aim of this paper was to study the hemispheric prevalence in dichotic listening task with regard to cognitive performance, as well as the presence or absence of central auditory dysfunction. Lesional cases presented a hemisphere prevalence in dichotic listening task with regard to cognitive performance, as well as the non-lesional cases tend to report the stimuli in the same side of EEG focus. Significant differences were found among the lesional and non lesional cases in relation to the digit span score and Coding subtest in right lesional cases versus right non-lesional cases. Both lesional and non-lesional group showed signs of central auditory dysfunction. We suggest that the dichotic listening and SSI and PSI test can be useful for a best comprehension of asymmetric neuropsychological performance in partial epilepsy.

Effect of lateralized epileptic discharges on the thought flow

“…The "lesion effect" characterized by preference for the normal side, can be observed in patients with lesional partial epilepsy, and the "paradoxical effect", characterized by the hemispheric preference where is the EEG paroxysmal epileptic activity in non-lesional partial epilepsy 33 . This could be confirmed by evidences that cerebral lesion really shifts the hemispheric preference for the intact side, while in the absence of cerebral lesion, the side of hemispheric preference shifts to the side of paroxysmal epileptic activity in interictal EEG 7,9 .…”