Magnetic source imaging demonstrates altered cortical distribution of function in patients with arteriovenous malformations.
OBJECTIVE
Arteriovenous malformations (AVMs) can be treated successfully, but treatment can pose unacceptable risks if the AVM is located in eloquent cortex. Because AVMs are developmental lesions, the location of primary cortical function may be deranged. We used magnetic source imaging (MSI) to identify the central sulcus and to determine whether primary cortical function was shifted in a set of 30 patients. We correlated these findings with outcome after treatment.


METHODS
We retrospectively analyzed the clinical data of 30 patients with AVMs who underwent MSI. Nonparametric statistical comparisons were made to correlate the proximity of AVMs to primary cortex and somatosensory shift to outcome at 12 months.


RESULTS
Using MSI, 14 patients (47%) were found to have AVMs involving primary cortex, and 10 patients (33%) were found to have shift in the somatosensory homunculus. Primary cortical involvement was neither required nor sufficient to cause shift (Mann-Whitney U test, z = -0.02, P = 0.31). Patients with AVMs involving primary cortex fared worse after treatment than did patients with AVMs that spared primary cortex (Mann-Whitney U test, z = -2.3, P = 0.02). The presence or absence of shift did not correlate with outcome after treatment (Mann-Whitney U test, z = -0.18, P = 0.48).


CONCLUSIONS
MSI showed that some patients with AVMs have abnormal cortical distribution of function. The involvement of primary cortex correlated with worse outcome after treatment. Our results suggest that preoperative functional imaging may help to better estimate treatment risks and ultimately to guide therapeutic planning.
Department of Neurological Surgery, University of California, San Francisco, San Francisco, California 94143, USA. vatese@neurosurg.ucsf.edu
G Edward
GE
Vates
Michael T
MT
Lawton
Charles B
CB
Wilson
Michael W
MW
McDermott
Van V
VV
Halbach
Timothy P L
TP
Roberts
Howard A
HA
Rowley
D000293:Adolescent; D000328:Adult; D000368:Aged; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000473:pathology / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D004292:Dominance, Cerebral; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000175:diagnosis* / Q000503:physiopathology* / Q000628:therapy; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D010296:Parietal Lobe / Q000098:blood supply; D012189:Retrospective Studies; D013003:Somatosensory Cortex / Q000503:physiopathology; D016896:Treatment Outcome