Background: Eloquent intracranial arteriovenous malformations (AVMs) located in the primary motor or somatosensory cortex (PMSC) carry a high risk of microsurgical morbidity.
Objective: To evaluate the outcomes of radiosurgery on PMSC AVMs and compare them to radiosurgery outcomes in a matched cohort of non-eloquent, lobar AVMs.
Methods: Between 1989 and 2009, 134 patients with PMSC AVMs underwent Gamma Knife radiosurgery with median radiographic and clinical follow-up of 64 and 80 months, respectively. Seizure (40.3%) and hemorrhage (28.4%) were the most common presenting symptoms. Pre-radiosurgery embolization was performed in 33.6% of AVMs. Median AVM volume was 4.1 cc (0.1-22.6 cc) and prescription dose was 20 Gy (7-30 Gy). Cox regression analysis was performed to identify factors associated with obliteration.
Results: The overall obliteration rate, including MRI and angiography, following radiosurgery was 63%. Obliteration was achieved in 80% of AVMs with volume less than 3 cc compared to 55% for AVMs greater than 3 cc. No prior embolization (P=0.002) and a single draining vein (P=0.001) were independent predictors of obliteration on multivariate analysis. The annual post-radiosurgery hemorrhage risk was 2.5%. Radiosurgery-related morbidity was temporary and permanent in 14% and 6% of patients, respectively. In comparing PMSC AVMs with matched non-eloquent, lobar AVMs, the obliteration rates and clinical outcomes following radiosurgery were not statistically different.
Conclusion: For patients harboring PMSC AVMs, radiosurgery offers a reasonable chance of obliteration with a relatively low complication rate. Eloquent location does not appear to confer the same negative prognostic value for radiosurgery that it does for microsurgery.
From: Radiosurgery for Primary Motor and Sensory Cortex Arteriovenous Malformations: Outcomes and the Effect of Eloquent Location by Ding et al.