Microsurgical Treatment for Trigeminal Schwannoma

Objective: To summarize the classifications and surgical approaches for trigeminal schwannoma (TS).

Methods: Patients who had TS between July 1996 and November 2011 were reviewed at the Skull Base Division of Neurosurgery at Beijing Tiantan Hospital.

Results: A total of 176 consecutive cases of TS were included, with 68 males and 108 females. Ages ranged from 14-66 years (average 40.6 years). Facial hypoesthesia was seen in 150 patients, headache and dizziness in 66, diploma in 32, infratemporal fossa tumor in 17, hydrocephalus in 19, limb weakness in 19, temporal muscle atrophy in 20, visual acuity decrease in 8, hearing loss in 12, ataxia in 13, and exophthalmia in 16. CT scans found petrosal apex erosion in 35 patients. Cystic change was found in 91 patients. The average of maximal diameter was 4.2 cm. The TSs were classified into cranioorbital type (9), cavernous sinus type (56), infratemporal fossa type (17), posterior fossa type (10), and petrous apex dumbbell type (84). Gross total resection was achieved in 156 patients, subtotal resection in 20. There was no death. Postoperatively, temporal muscle atrophy occurred in 74; corneal ulcer in 12; worsening facial numbness in 47; oculomotor palsy in 12; abducens palsy in 9, transit limbs weakness in 5, with tight adherence to brainstem; temporary aphasia in 12 because of brain contusion in the dominant temporal lobe; and CSF leakage in 7, 2 of which needed repair via open surgery. Follow-up data were available for 15l patients, with follow-up time ranging from 6-157 months. Tumor recurrence was found in nine patients.

Conclusions: The most suitable approach is closely interrelated with the classification and extension of tumors.