Plasticity in the Mature Brain: Patterns of Cortical Reorganization Following Brain Lesion Removal

Hypothesis

Hypothesis

Hypothesis:
1. Recovery processes for functions lost following resection of acquired and congenital lesions differ with respect to the volume and areas of activity associated with recovery. In particular, congenital lesions will be associated with less total activity than acquired lesions.

2. Recovery of language and sensorimotor functions involves recruitment of homologous regions of the contralateral hemisphere, in addition to the expected ipsilateral functional regions.

Goals:
1. To compare the recovery processes for functions lost following removal of congenital and acquired lesions.

2. To examine the specific brain areas and neural networks utilized by the brain to recover from postoperative language, sensory, and motor deficits.

3. To compare the volume and areas of brain activity during postoperative recovery from deficits due to cortical and fiber tract disruption versus deficits from swelling.

Methods:
This study will take advantage of the opportunity to obtain baseline functional magnetic resonance imaging (fMRI) localization of function preoperatively in all patients (in conjunction with Joy Hirsch, Ph.D.). In addition, based on intraoperative mapping of function before and after lesion resection, each patient's deficit will be precisely characterized. Using a within-subject, repeated measure design, the researchers will analyze sequential postoperative fMRI examinations to determine which brain areas form the specific functional networks that are utilized for the recovery of language and sensory/motor functions following resection of acquired and congenital lesions.