Displacement of hand representation to the contralateral hemisphere may predict neurologic recovery after arteriovenous malformation resection from the sensorimotor cortex

Patients who have an arteriovenous malformation (AVM) in the sensorimotor cortex can have displaced function. The significance of this finding and its relationship to recovery from surgery is not known. We present the case of a 21-year-old man with medically intractable seizures caused by a left motor cortex AVM. Functional magnetic resonance imaging (fMRI) displayed bilateral representation of right hand function that was greatest in the right hemisphere. The AVM was first embolized and then microsurgically resected. Although he developed a transient monoplegia of the right upper extremity and speech difficulties after surgery, his deficits improved dramatically within several days and ultimately completely resolved. We postulate that the displacement of hand functional representation to the hemisphere contralateral to the AVM may have been the reason for this patient's expeditious recovery. FMRI may help predict the risk of deficit and chances for recovery in patients who have AVMs in the eloquent cortex. This noninvasive physiologic technique may replace anatomic criteria of inoperability for vascular malformations.