Risk factors of postoperative trigeminal neuropathy in surgical treatment of trigeminal schwannomas

Trigeminal schwannomas are rare benign tumors originating from the Schwann cells of the trigeminal nerve. Despite the common occurrence of trigeminal neuropathy in trigeminal schwannomas, a detailed analysis has not yet been performed because of the rarity of this disease. This study aimed to analyze trigeminal neuropathy in trigeminal schwannoma resection and identify the risk factors for postoperative worsening of trigeminal neuropathy.

A retrospective analysis of 86 surgical cases was performed at our institution between 1975 and 2018. Obtained parameters included age, sex, diagnosis, reoperation, tumor size, tumor location, presence or absence of cysts, surgical approach, degree of tumor removal, and pre/postoperative trigeminal neuropathy. Uni- and multivariate analyses were performed to identify the risk factors for worsening postoperative sensory disturbances.

Of 83 patients, 58.1% had preoperative trigeminal neuropathy. Postoperative sensory disturbance occurred in 27.9%, with worsening in two cases and de novo symptoms in 22 cases. Regarding risk factors for worsening postoperative sensory disturbances, older age, smaller tumor size, middle and posterior (MP) type, gross total removal (GTR), and anterior transpetrosal approach were identified in the univariate analysis, while MP type and GTR were identified in the multivariate analysis.

This study analyzed trigeminal neuropathy in trigeminal schwannomas in detail and identified tumor location and removal rate as risk factors for worsening postoperative sensory disturbances. Treatment strategies to reduce the risk of trigeminal neuropathy should be considered.