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Condition/Disorder Synonyms

  • Vestibular schwannoma

  • Acoustic schwannoma

  • Cerebellopontine angle tumor

ICD-9-CM Code

225.1 Benign neoplasm of cranial nerves1

ICD-10-CM Code

D33.3 Benign neoplasm of cranial nerves2

Preferred Practice Patterns

Key Features


  • Disorder of the vestibulocochlear nerve (8th cranial nerve) that carries vestibular and auditory input from the inner ear to the central nervous system

  • Slow-growing (usually 1 to 2 mm/year), benign tumor of the myelin-forming Schwann cells that surround the vestibular portion of the 8th cranial nerve

  • Tumor most commonly originates from the inferior vestibular branch

  • Tumor forms in the internal auditory canal and can extend into the cerebellopontine angle

  • Typically results in a gradual onset of high-frequency sensorineural hearing loss, tinnitus, sense of ear fullness, unsteadiness, dizziness, vertigo

  • As tumor grows, there may be facial nerve involvement (resulting in facial numbness or weakness), headache, hydrocephalus, incoordination, diplopia, hoarseness, difficulty swallowing, brainstem compression, death

  • Tumors classified as sporadic, cystic, or neurofibromatosis type II

Essentials of Diagnosis

  • Physical exam normal, unless the cerebellum or brainstem is compromised

  • Audiogram abnormal

  • Imaging studies abnormal

  • Neurotologic exam abnormal

  • Thorough and detailed history is essential to distinguish acoustic neuroma from other vestibular disorders and central pathology

General Considerations

  • Patients typically present with complaints of progressive hearing loss and loss of balance worsening gradually over several months

  • If tumor growth progresses, may present with other cranial nerve (especially V and VII), brainstem, or cerebellar signs and symptoms


  • Uncommon in general population, but most common cerebellopontine angle tumor (80% of these tumors)

  • Unknown etiology

  • Typically occurs in 5th or 6th decade of life

  • Mortality has been nearly eliminated; morbidity rates have been significantly reduced due to improved techniques for early diagnosis and improved treatment approaches

Clinical Findings

Signs and Symptoms

  • Typical symptoms include tinnitus (ringing or noises in the ear) and sense of ear fullness

  • Patients occasionally present with complaints of vertigo or vague report of dizziness

  • May complain of blurred vision due to oscillopsia (perceived movement of the environment)

  • Unexplained unilateral sensorineural hearing loss with high-frequency loss on audiogram

  • Imbalance, as manifested by difficulty standing and walking

  • Increased risk of falling

  • Vague sense of dizziness; may be constant or increasingly severe with head movement

  • Abnormal auditory brainstem response

  • Hypoactive or absent caloric response

  • May observe nystagmus in room light or with fixation removed

  • May present with central symptoms, such as diplopia, dysarthria, dysphagia, dysmetria, numbness, or weakness if tumor has compressed brainstem ...

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