schwannomakustisk

Schwannomakustisk, more commonly known in English as vestibular schwannoma or acoustic neuroma, is a benign tumor arising from Schwann cells that surround the vestibulocochlear nerve (cranial nerve VIII). The majority originate from the vestibular portion of the nerve and grow within the internal auditory canal and the cerebellopontine angle.

Clinically, the hallmark is progressive unilateral sensorineural hearing loss, often accompanied by tinnitus and imbalance or vertigo. In larger tumors, there may be facial numbness or weakness due to compression of adjacent cranial nerves. Because growth is typically slow, symptoms may develop gradually over months to years.

Diagnosis rests on imaging and audiology. Magnetic resonance imaging (MRI) with gadolinium enhancement is the gold standard for confirmation and to delineate extent and brain involvement. Audiologic testing typically shows asymmetric sensorineural hearing loss. Brainstem auditory evoked responses may be used when MRI is not immediately available. Computed tomography can be supplementary, especially to assess bone remodeling.

Management depends on tumor size, growth rate, hearing status, patient age, and the presence of neurofibromatosis type 2 (NF2). Options include observation with regular MRI for small, slow-growing tumors; microsurgical resection via retrosigmoid, translabyrinthine, or middle fossa approaches; and stereotactic radiosurgery (e.g., Gamma Knife) for selected cases. The goal is tumor control while preserving as much hearing and facial nerve function as possible.

Prognosis is generally favorable for a benign lesion, though treatment risks vary with approach and tumor size. Bilateral vestibular schwannomas are characteristic of NF2, whereas unilateral tumors are far more common in the general population.