Changes in hemispheric asymmetry following early brain damage and its impact on cognitive processing
Date
1995
Authors
Stickgold, Kira Emily
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Abstract
Volumetric measurements of the hemispheres were derived using Magnetic Resonance (MR) images from patients with medical refractory seizures. Hemispheric asymmetry quotients were determined using the formula 100 X (left volume - right volume)/(left volume + right volume) and related to side of seizure origin, age of onset, hemisphere lateralization for speech, and IQ measures from the Wechsler Intelligence Scales (Wechsler Adult Intelligence Scale - Revised; and Wechsler Intelligence Scale for Children - Revised). Hemispheric asymmetry and side of seizure origin were associated, (F(l ,39) = 6.43, p < .005); that is, a larger left hemisphere occurred in the context of right, but not left-sided, seizure origin. Age of seizure onset, however, did not affect this asymmetry. In contras~ to previous studies, there were no significant correlations between atypical asymmetry (right hemisphere > left hemisphere) and VIQ - PIQ scores. The relation between hemispheric speech dominance and anatomical asymmetry approached, but did not reach statistical levels of significance (F,(1,43) = 2.03, p<.08).