Facial nerve palsy after middle meningeal artery embolization for chronic subdural hematoma: illustrative case.

backgroundMiddle meningeal artery embolization (MMAE) has emerged as a safe and effective minimally invasive alternative to surgical evacuation of chronic subdural hematoma (cSDH), both as adjuvant therapy and as a stand-alone treatment. Despite its advantages, rare complications such as facial nerve palsy (FNP) may occur. Such complications have rarely been reported in the literature in the context of cSDH, with only 7 other cases. OBSERVATIONS: The authors present the case of FNP after MMAE for cSDH and highlight the mechanism of injury, management, and preventive strategies that should be considered prior to endovascular interventions, while summarizing the previously reported cases. LESSONS: Special attention must be given to the endovascular technique implicated and to the complex anatomy of the middle meningeal artery (MMA) to reduce the incidence of such complications. Management of such complications is extrapolated from the available literature on facial nerve injuries and is mainly supportive through eye moisturization, facial muscle rehabilitation, and steroids. Although no consensus has been reached for prevention, some recommendations have been given throughout the literature, such as distal microcatheter positioning, proximal mechanical blockage with balloon-assisted flow reversal, and the use of coil-only embolization or high-viscosity embolic agents with a particle size ≥ 150 μm. https://thejns.org/doi/10.3171/CASE25866.