Massive brain swelling after cranioplasty in the setting of severe sunken flap syndrome: illustrative case

This case highlights the malignant presentation pattern of MBSC and underscores severe SSF syndrome as a critical preoperative risk state. Sudden restoration of the cranial vault may precipitate a pathological intracranial pressure surge in patients chronically adapted to intracranial hypotension. Cranioplasty timing and seizure activity may impact MBSC risk. Further study is needed to clarify optimal timing strategies and prophylactic antiseizure therapy. Heightened perioperative vigilance and explicit risk counseling may be necessary, as outcomes remain poor once the MBSC cascade is established. https://thejns.org/doi/10.3171/CASE2659.