Wyburn-Mason disease: Management of a Spetzler-Martin grade 5 arteriovenous malformation with predominant thalamic involvement.

Wyburn-Mason disease (WMD) is a rare congenital phakomatosis known for its complex arteriovenous malformations (AVMs) predominantly affecting the brain and ocular structures. We present the case of a 19-year-old female with an unruptured Spetzler-Martin grade 5 left thalamic AVM, who initially exhibited progressive visual impairment and migraines. Following diagnosis, she was treated with trametinib, a MEK inhibitor; however, nine months later, she developed acute complications, including left monocular blindness and right hemisensory loss. Imaging revealed narrowing of the left internal carotid artery and ischemia, leading to the discontinuation of trametinib. Her condition stabilized with gabapentin and supportive therapies. This case emphasizes the potential therapeutic role and risks of MEK inhibitors in managing high-grade AVMs in WMD and highlights the need for individualized management and careful monitoring in such cases.