Psychopathology and epilepsy: Comparing the left and right hemispheres

Abstract

The relative roles of the cerebral hemispheres in the control of emotion are controversial. Depression, hypomania, psychosocial adjustment, minor daily stress, and aspects of personality were evaluated as a function of a unilateral seizure focus. Eighty adults between the ages of 18 and 50 with idiopathic epilepsy were recruited from private neurologists' patient files, an outpatient seizure clinic, and an inpatient monitoring unit. In addition to completing questionnaires reflecting psychopathology, subjects were interviewed about their age, level of education, and marital status, and were administered two neuropsychologic instruments to estimate their current intellectual status.;Three groups of subjects (29 left-hemispheric seizure focus, 20 right-hemispheric seizure focus, and 31 generalized spike and wave controls) self-administered the Beck Depression Inventory (BDI), the Washington Psychosocial Seizure Inventory (WPSI), the Hassles and Uplifts Scales, and the Minnesota Multiphasic Personality Inventory-2 (MMPI-2). Only subjects with a minimum estimated IQ {dollar}>{dollar}70, at least eight years of formal education, and a documented focal EEG or generalized spike and wave EEG were admitted for participation. Subjects were excluded if they had abnormal neuroimaging studies, a history of significant head trauma or meningitis, coexisting medical illnesses, or psychiatric disorders that required medication. A diagnosis of mesial temporal sclerosis was not considered an exclusionary criterion. Subjects who were taking phenobarbital or a benzodiazepine were also excluded.;Data were analyzed using a one-way multivariate analysis of variance (MANOVA) using Hotelling's T, a one-way analysis of variance (ANOVA) with post-hoc analysis by Newman-Keuls test, and a chi-square test for certain analyses. There was one independent variable, seizure type (left-hemispheric focus, right-hemispheric focus, and primary generalized epilepsy), and 40 dependent variables analyzed separately (1 BDI score, 8 WPSI summary scores, 4 Hassles and Uplifts Scales scores, 12 MMPI-2 Basic Scales scores, and 15 MMPI-2 Content Scales scores).;Although results were expected to be consistent with the contralateral hemisphere release theory of emotion, a significant difference in terms of uplifts intensity and a consistent trend among most of the other scores paralleled the unilateral control theory of emotion. Most mean scores of psychopathology were greater in subjects with a seizure focus in the right hemisphere than in subjects with a seizure focus in the left hemisphere. Concordance with the unilateral theory of emotion emphasizes the need for medical professionals to be alert to the unique assessment and rehabilitative concerns of individuals with a chronic seizure disorder.