Management of Slowly Progressive Facial Weakness in Patients With Benign Tumors of the Facial Nerve

Benign facial nerve tumors have unique presentations granting distinct diagnostic and management implications. Unlike acute-onset facial paralysis, the gradual, intermittent course complicates diagnosis, treatment strategy, and timing, especially when considering potential reanimation. This study presents our institutional experience and proposes approaches to management and evaluation of patients with slowly progressive facial weakness due to benign tumors.

A retrospective review included patients between August 2009 and April 2026 with slowly progressive facial weakness or hemifacial spasm due to a benign facial nerve tumor. Demographics, facial palsy history, tumor characteristics, treatment strategies, reanimation procedures, and outcomes were analyzed.

Fifteen patients met inclusion criteria with a mean age of onset of 45 years. Sixty-seven percent were initially misdiagnosed. Forty-seven percent presented with synkinesis. The most common tumor type was facial nerve schwannoma (60%). Forty percent underwent complete resection, 27% received radiation, and 27% are under observation. Six patients underwent dynamic facial reanimation: proactively (before tumor extirpation) in three cases, with one undergoing both proactive and concomitant reanimation during extirpation, concomitantly with extirpation in one, and following radiation in one. All achieved recovery of motion on average 3.7 months (range 2-7) later. Two patients are currently planned for reanimation.

Benign facial nerve tumors require individualized management based on functional trajectory, tumor characteristics, and patient preference. Treatment options range from observation and radiation to surgical extirpation, but due to the slowly progressive and partial nature of the facial paralysis, the reanimation strategy is guided not only by mimetic musculature viability but also by patient preference on timing. In patients with progressive weakness and anticipated nerve sacrifice during extirpation, proactive reanimation using nerve transfers, cross facial nerve grafts, and free functional muscle transfer should be considered early to establish reinnervation pathways before the denervation window closes, avoiding irreversible facial paralysis.