Ipsilateral subcortical atrophy associated with temporal lobectomy

Stereologic methods for determining the volume of cerebral structures in vivo via magnetic resonance imaging have identified unilateral hippocampal atrophy among patients with complex partial epilepsy of temporal lobe origin. Metabolic imaging has also identified altered metabolism in temporal as well as extratemporal regions among these patients. As the temporal cortex and subcortical nuclei of the limbic system are reciprocally connected with striatal projection fields, we examined the putamen nuclei for evidence of associated extratemporal volume asymmetry in patients before and after temporal lobectomy. There was no evidence of preoperative putamen volume asymmetry, but a significant post-operative decrement in ipsilateral putamen volume was observed. The magnitude of postsurgical putamen volume asymmetry was correlated with the duration of time since resection. Progressive degeneration of extratemporal projections of the temporal lobe may occur in association with temporal lobectomy.