II. Pathophysiology

  1. Benign Acoustic Nerve tumor
  2. Majority of lesions arise from vestibular branch CN 8

III. Epidemiology

  1. Represents 8% of all Brain Tumors
  2. Represents 80% of posterior fossa tumors
  3. Incidence: 1 per 100,000 persons in the United States
  4. Otolaryngologists sued most on missed Acoustic Neuroma

IV. Signs

  1. Unilateral and persistent Tinnitus beyond 1 month
  2. Gradually progressive unilateral Sensorineural Hearing Loss
    1. Represents only 1-2% of unilateral Hearing Loss causes
  3. Episodic Vertigo presenting symptom in 10% of cases

V. Diagnostics

  1. Pure tone Audiometry (formal testing with audiology)
    1. Asymmetric Hearing Loss may suggest Acoustic Neuroma
      1. Average difference >10 dB over 1 to 8 KHz range (high Test Sensitivity for Acoustic Neuroma)
      2. Average difference >15 dB over 0.5 to 3 KHz range (high Test Specificity for Acoustic Neuroma)
      3. Cheng (2012) Otolaryngol Head Neck Surg 146(3): 438-47 [PubMed]
  2. Other audiology evaluation
    1. Acoustic Reflex Testing
    2. Auditory Brainstem Testing (ABR)
  3. Electronystagmography (ENG)
    1. Abnormal in 50% of cases, but non-specific

VI. Imaging

  1. MRI brain with contrast and including Internal Auditory Canals
    1. Best study for identifying Acoustic Neuroma
    2. Replaces Auditory Brainstem Testing (ABR) for Acoustic Neuroma diagnosis

VII. Management: Otolaryngology Referral for Surgical Excision

  1. Most otolaryngologists do not preserve hearing
  2. Hearing preservation technique has 50% success

Images: Related links to external sites (from Bing)

Related Studies (from Trip Database) Open in New Window

Ontology: Acoustic Neuroma (C0027859)

Definition (MEDLINEPLUS)

An acoustic neuroma is a benign tumor that develops on the nerve that connects the ear to the brain. The tumor usually grows slowly. As it grows, it presses against the hearing and balance nerves. At first, you may have no symptoms or mild symptoms. They can include

  • Loss of hearing on one side
  • Ringing in ears
  • Dizziness and balance problems

The tumor can also eventually cause numbness or paralysis of the face. If it grows large enough, it can press against the brain, becoming life-threatening.

Acoustic neuroma can be difficult to diagnose, because the symptoms are similar to those of middle ear problems. Ear exams, hearing tests, and scans can show if you have it.

If the tumor stays small, you may only need to have it checked regularly. If you do need treatment, surgery and radiation are options.

If the tumors affect both hearing nerves, it is often because of a genetic disorder called neurofibromatosis.

NIH: National Institute of Deafness and Communication Disorders

Definition (NCI) A type of benign brain tumor that begins in the Schwann cells, which produce the myelin that protects the acoustic nerve - the nerve of hearing.
Definition (MSH) A benign SCHWANNOMA of the eighth cranial nerve (VESTIBULOCOCHLEAR NERVE), mostly arising from the vestibular branch (VESTIBULAR NERVE) during the fifth or sixth decade of life. Clinical manifestations include HEARING LOSS; HEADACHE; VERTIGO; TINNITUS; and FACIAL PAIN. Bilateral acoustic neuromas are associated with NEUROFIBROMATOSIS 2. (From Adams et al., Principles of Neurology, 6th ed, p673)
Concepts Neoplastic Process (T191)
MSH D009464
SnomedCT 985004, 389982003, 269643009, 154621002, 126949007
English Acoustic Neurilemmomas, Acoustic Neuromas, Acoustic Schwannomas, Neurilemmoma, Acoustic, Neurilemmomas, Acoustic, Neuroma, Acoustic, Neuromas, Acoustic, Schwannoma, Acoustic, Schwannomas, Acoustic, Neurinoma, Acoustic, Acoustic Neurinoma, Acoustic Neurinomas, Neurinomas, Acoustic, Neurilemoma, Acoustic, Acoustic Neurilemoma, Acoustic Neurilemomas, Neurilemomas, Acoustic, Schwannoma, Vestibular, Vestibular Schwannoma, Schwannomas, Vestibular, Vestibular Schwannomas, Neuroma, Acoustic [Disease/Finding], Tumor, Acoustic, Tumors, Acoustic, Acoustic Tumor, Acoustic Tumors, Neurinoma of the Acoustic Nerve, acoustic neuroma, acoustic neuroma -, acoustic neuromas, acoustic schwannoma, Neuroma;acoustic, acoustic neuroma brain tumor, schwannoma vestibular, vestibular schwannomas, acoustic neurinoma, vestibular schwannoma, Vestibular schwannoma (disorder), Neuroma - acoustic, Acoustic neuroma, Acoustic schwannoma, Vestibular schwannoma, AN - Acoustic neuroma, Acoustic neurinoma, Acoustic neurilemmoma, Acoustic neuroma (disorder), acoustic; neurinoma, Acoustic Neuroma, Acoustic Neurilemmoma, Acoustic Schwannoma, Vestibular Neurilemmoma
Italian Neuroma del nervo acustico, Schwannoma del nervo acustico, Neurinoma del nervo acustico, Schwannoma vestibolare, Neurinoma dell'acustico, Schwannoma dell'acustico, Neurinoma acustico
Spanish neurinoma acústico, Schwanoma del acústico, Neurinoma del acústico, neurimoma acústico, Schwannoma Vestibular, neurilemoma acústico, neuroma acústico (trastorno), neuroma acústico, shwannoma vestibular, Neuroma acústico, Neuroma Acústico, Schwannoma Acústico
Dutch neurinoma acusticum, acusticusschwannoom, acusticusneurinoom, Akoestisch neuroom, Neuroom, akoestisch, Schwannoom, akoestisch
German Akustikusschwannom, Schwannom, vestibuläres, Vestibuläres Schwannom, Akustikus-Neurinom, Akustikusneurom, Neurilemmom, Akustikus-, Neurinom, Akustikus-, Neurom, Akustikus-, Schwannom, Akustikus-, Akustikusneurinom
Portuguese Schwanoma do acústico, Schwanoma Vestibular, Schwannoma Vestibular, Schwannoma Vestibular Melanocítico, Schwannoma Acústico, Neurinoma do acústico, Neuroma Acústico, Schwanoma Acústico
Japanese 聴神経シュワン細胞腫, チョウシンケイシュ, チョウシンケイシュワンサイボウシュ, チョウシンケイショウシュ, 片側性聴神経腫瘍, 神経腫-聴-片側性, 聴覚腫, 聴神経腫, 聴神経腫瘍-片側性, 片側性聴神経腫, 聴神経鞘腫, 神経鞘腫-聴, 内耳神経腫瘍, 聴神経腫瘍, 神経腫-聴
Swedish Akustikusneurinom
Czech neurom akustiku, Schwannom akustiku, Neurinom akustiku, Neurom akustiku
Finnish Akustikusneurinooma
Russian SLUKHOVOGO NERVA NEVROMA, SHVANNOMA AKUSTICHESKAIA, NEVRINOMA AKUSTICHESKAIA, NEVROMA AKUSTICHESKAIA, NEVROMA SLUKHOVOGO NERVA, NEVRILEMMOMA AKUSTICHESKAIA, НЕВРИЛЕММОМА АКУСТИЧЕСКАЯ, НЕВРИНОМА АКУСТИЧЕСКАЯ, НЕВРОМА АКУСТИЧЕСКАЯ, НЕВРОМА СЛУХОВОГО НЕРВА, СЛУХОВОГО НЕРВА НЕВРОМА, ШВАННОМА АКУСТИЧЕСКАЯ
Croatian NEUROM, AKUSTIČNI
Polish Nerwiak nerwu słuchowego
Hungarian Acustikus neurinoma, Acustikus neuroma, Acustikus schwannoma
Norwegian Akustikusnevrinom
French Neurinome de l'acoustique, Neurinome du nerf auditif, Schwannome acoustique, Schwannome vestibulaire, Neurinome acoustique, Neurinome de la 8ème paire crânienne, Neurinome de la VIIIème paire crânienne, Neurinome de la huitième paire crânienne, Neurinome du nerf acoustique, Névrome acoustique, Schwannome de l'acoustique