Vestibular schwannoma (acoustic neuroma) most commonly presents with ipsilateral disturbances of acoustic, vestibular, trigeminal and facial nerves [5]. Contralateral trigeminal nerve dysfunction as a false localizing sign in acoustic neuroma has been documented [3, 6, 7]. Contralateral facial pain presenting as trigeminal neuralgia has been mentioned as false localizing sign for posterior fossa and cerebellopontine angle tumors [1, 10, 4, 2]. However presentation of the vestibular schwannoma with contralateral facial pain is quite uncommon. Among 156 patients with vestibular schwannoma who underwent surgery at Sina hospital during past 6 years, we encountered one case with this unusual presentation.
Case presentation
A 44-year old woman presented with one month history of right hemifacial pain, ataxia, progressive vertigo and left sided hearing loss. She described the pain as burning and constant without any relation to a specific position or movement. The pain had started gradually, and had become increasingly annoying. The patient had saught medical consultation mainly for her facial pain. Physical examination revealed mild left facial paresis. The right of her face was dysesthetic in territories of all three subdivisions of trigeminal nerve. Her cerebellar tests were abnormal on the left side. She also had left sided hearing loss and hypoactive corneal reflexes on both sides . MRI studies with and without contrast showed a giant (45 × 44 × 42 mm) left cerebellopontine angle nonhomogenous mass compatible with a vestibular schwannoma (Fig. 1). The rostral and medial extension of the tumour and distortion of the brainstem was remarkable in this case. The patient was operated upon by retrosigmoid approach in sitting position. Pathologic examination of the tumour confirmed the preoperative diagnosis of vestibular schwannoma. Postoperatively (Fig. 2) her right hemifacial pain was relieved and her corneal reflexes returned to normal activity. The left facial nerve function could not be preserved.