Differential immunologic effects of language-dominant and nondominant cerebral resections

Objective: To demonstrate whether the cerebral hemispheres (language dominant versus nondominant) affect immune function differentially in humans by delineating the effects of resections for epilepsy surgery on T-cell indices. Background: Cerebral lateralization has been postulated to affect immunomodulation. Differential effects of left versus right cerebral lesions on T-cell numbers and responsiveness have been demonstrated in animals, but the effects in humans are unclear. Methods: Pre- and postoperative changes in T-cell indices were examined in relation to side of language dominance in patients undergoing epilepsy surgery. Results: Absolute lymphocyte count, total T cells (CD3⁺), helper T cells (CD3⁺⁺), cytotoxic/suppressor cells (CD3⁺8⁺), and total suppressor cells (CD8⁺) were reduced after language- dominant resections, but were increased after nondominant resections. Conclusions: Although the mechanisms are not fully elucidated, the results demonstrate differential immunologic responses in humans to focal cerebral lesions as a function of cerebral lateralization.