Inflammation as a Key Driver for Chronic Subdural Hematomas

Chronic subdural hematomas (cSDHs) have risen in incidence to ≈17 to 19 cases per 100 000 persons per year over the recent decade, especially in the elderly population, with an estimated incidence of up to 355 cases per 100 000 per year in those ≥85 years. cSDHs are projected to be the most common neurosurgical condition by 2030. Recurrence rates with current treatment approaches, such as surgical evacuation with burr hole craniostomy or craniotomy, are high. These treatments often do not address the underlying inflammatory process, which is a key driver in cSDH development and progression. cSDHs develop when trauma to the inner dural border cell layer leads to an inflammatory response promoting neoangiogenesis, the ingrowth of new fragile vessels that are highly prone to leakage. Subsequent rebleeding, exudation, and incomplete resorption exacerbate the inflammatory response, leading to a self-perpetuating process. This review provides an overview of the inflammatory mechanisms involved in cSDHs, highlighting key biomarkers and cellular pathways, as well as associated translational clinical implications. Expanding upon existing therapies, reexamining these pathways presents opportunities to identify future potential therapeutic targets.