An Evaluation of Motor Function in Surgery for Cerebral Arteriovenous Malformations via 3-Tesla Magnetic Resonance Tractography.

Purpose: To investigate the role of magnetic resonance tractography (MRT) for the evaluation of motor function in surgery for brain arteriovenous malformations (AVMs).

Methods: Of 112 patients with brain AVMs operated on by the senior author (K.K.) between 2000 and 2022, 22 consecutive patients with frontal, parietal, temporal, sylvian, and insular AVMs underwent an evaluation of neural tracts via 3-tesla (3 T) MRT before and after surgery. There were 12 men and 10 women (mean age 29.0 ± 13.6 years). Here, 14 patients presented with hemorrhage, five with epilepsy, and three with ischemic symptoms. Spetzler-Martin grade (SMG) assessments were I in six patients, II in nine, III in six, and IV in one. The microsurgical resection of the AVMs achieved total removal in all 22 patients.

Results: The presence of preoperative motor dysfunction and the minimal distance between an AVM and the corticospinal tract (MDACST) was significantly related to transient motor deterioration. The presence of preoperative motor dysfunction, a tract injury on postoperative MRT, the presence of transient motor dysfunction, and the MDACST were significantly related to permanent motor dysfunction. Multivariate analysis also suggested that the MDACST was one of the most predictive factors of transient motor deterioration and permanent motor dysfunction. The cutoff value at the receiver operating characteristic analysis indicated that MDACST less than 16 mm and MDACST less than 8 mm could highly predict transient motor deterioration and permanent motor dysfunction, respectively.

Conclusions: Surgery on an AVM with MDCT less than 16 mm would probably induce transient motor deterioration, and less than 8 mm would probably cause permanent motor dysfunction.