Clinical and cognitive outcome after surgical resection of cerebral AVMs in language areas

Background: The management cerebral AVMs is not always clear - especially if located in eloquent areas - and could range between observation and microsurgical resection. Surgery is highly demanding and can be associated with post-operative neurological sequelae. The present study aims to analyze how natural history and clinical-radiological features impact the clinical and cognitive outcome after surgery for cerebral arteriovenous malformations (AVMs) located in language areas. Methods: A retrospective cohort study was conducted on a continuous series of 311 patients operated on for cerebral AVMs at a single institution by a single neurosurgeon between 1990 and 2020. Speech areas were classified in 4 regions: frontal operculum, inferior parietal lobule, superior temporal gyrus, and sylvian-insular. Post-operative deficits were classified as transient and permanent; the latter were further divided into mild (modified Rankin score ≤2) and significant (mRS ≥ 3). A post-operative neuropsychological evaluation was conducted at follow-up to assess long-term cognitive deficits. Results: A total of 63 patients were considered eligible; the AVM was located in the frontal operculum in 20 cases, in the inferior parietal lobule in 8 cases, in the superior temporal gyrus in 27 cases and in the sylvian-insular region in 8 cases. The ruptured and unruptured AVMs ratio was 1:1.1. Patients with bleeding AVMs showed preexisting neurological deficit as a determining factor for post-operative morbidity, regardless of the AVM volume. Post-operative deficits in unruptured AVMs were mostly transient (63.6 %); a significant deficit was present in 1 case with AVM volume >20 cm3. Neuropsychological deficits were higher in ruptured and in large volumes (>20 cm3) AVMs cases. Conclusions: Surgical management of cerebral AVMs in speech areas is safe, especially for smaller AVMs (<20 cm3). In ruptured AVMs the clinical outcome is influenced mostly by the hemorrhage, whereas unruptured AVMs showed mild neurological sequelae.