Cortical plasticity in patients with cerebral arteriovenous malformations

The aim of this review is to ascertain the evidence for cortical plasticity in arteriovenous malformation (AVM) patients. Chronic hypoperfusion due to vascular steal from cerebral AVM can result in a translocation of eloquent neurological functions to other brain areas, a phenomenon known as cortical plasticity. We performed a systematic literature review of the studies that have evaluated cortical plasticity in AVM patients. A total of 22 studies from 1996 to 2014 were included for the analyses. The evaluation of cortical plasticity was performed prior to AVM intervention in 109 patients, and during or after AVM intervention in 18. The most commonly assessed neurological functions were motor in 85% and language in 11% of the former cohort, and motor in 78% and language, cognition, and memory each in 39% of the latter cohort. Functional MRI was the most frequently used method for evaluating cortical plasticity, and was performed in 63% of the former and 56% of the latter cohort. In conclusion, cortical plasticity appears to be influenced by both AVM pathogenesis and intervention. Given the limited evidence that is currently available for cortical plasticity in AVM patients, further studies are warranted to determine its incidence and impact on long term clinical outcomes.