Sudden Hearing Loss

The purpose of this patient summary is to provide guidance on the diagnosis, management, and follow-up of sudden hearing loss. It focuses on sudden idiopathic sensorineural hearing loss in adult patients aged 18 years and older, and mainly on sudden sensorineural hearing loss with no obvious known cause.

• This patient summary focuses on idiopathic sudden sensorineural hearing loss. Idiopathic means that there is no clear cause.
• Definitions of types of hearing loss covered in this patient summary:
  • Sudden Hearing Loss: A rapid-onset subjective sensation of hearing impairment in one or both ears.
  • Sensorineural Hearing Loss: Hearing loss resulting from problems in the inner ear and/or the auditory nerve that connects the inner ear to the brain.
  • Sudden Sensorineural Hearing Loss: A subset of sudden hearing loss that:
    • Is sensorineural in nature, occurs due to a problem with the sound signals not reaching the brain properly.
    • occurs within a 72-hour window
    • meets certain audiometric criteria (referring to hearing test results).
• Other types of hearing loss, including conductive hearing loss and mixed hearing loss, are not covered in this patient summary.
• The cause of sudden sensorineural hearing loss is often unknown. If it is not recognized and treated promptly, it can result in long-lasting hearing loss and tinnitus (ringing in the ears), and reduced quality of life.
• Sudden sensorineural hearing loss is usually treated with one or more of the following:
  • Steroid therapy with corticosteroids
    • Medications taken by mouth to reduce inflammation
  • Steroid therapy with intratympanic steroids
    • Medications injected into the inner ear to reduce inflammation
  • Hyperbaric oxygen therapy (in combination with steroid therapy)
    • Hyperbaric oxygen uses oxygen to reduce inflammation
• The treatment options for sudden sensorineural hearing loss usually depend on the following:
  • How long it has been since any initial symptoms started
  • Whether previous therapies had been tried, and if so, if they were successful.
  • Salvage therapy is any treatment given 2 weeks after the start of sudden hearing loss even if that initial treatment was just observation.
• Procedures used to diagnose and assess sudden sensorineural hearing loss include:
  • Audiometry (hearing test)
  • MRI or Auditory Brainstem Response
    • MRI: gives a detailed image
    • Auditory brainstem response: measures how sound travels to the brain

1. What is causing the problem?
   1. The cause of sudden sensorineural hearing loss (SSNHL) is often not readily apparent and thus called idiopathic. It rarely affects both ears and can be associated with other symptoms such as ringing (tinnitus), dizziness (vertigo) and fullness in the ear.
2. How is sudden hearing loss diagnosed?
   1. The sudden change in hearing is obvious to you and may be accompanied by loud ringing, vertigo (spinning sensation or balance problems), and/or pressure in the ear and should be evaluated as quickly as possible. Your health care provider will take a comprehensive history and complete a physical exam. Routine labs and x-rays are not recommended, but a hearing test (audiogram) should be done.
3. Will my hearing come back?
   1. Approximately 1/3 to 2/3 of patients with SSNHL may recover some percentage of their hearing within two weeks. Those who recover half of their hearing in the first two weeks have a better prognosis. Patients with minimal change within the first two weeks are unlikely to show significant recovery. Additionally, patients with dizziness at the time of onset of SSNHL have a poorer prognosis.
4. Is there additional testing needed with SSNHL?
   1. SSNHL can rarely be associated with benign tumors of the vestibular nerve. These tumors are called vestibular schwannomas and can lead to progressive hearing loss, balance problems and in some cases compression of the brainstem with severe neurologic symptoms. Your provider may order an MRI to screen for these tumors. While an MRI of the brain and internal auditory canals is the most sensitive test, some patients opt for an Auditory Brainstem Response (ABR. This is a less sensitive screening tool but is less expensive and does not require being in the confined space of the MRI machine. If the ABR is abnormal, good practice requires an MRI.
5. How is sudden hearing loss treated?
   1. Many treatments have been proposed for SSNHL. Watchful waiting is an alternative to active treatment since between 1/3 and 2/3 of patients may recover hearing on their own and can be monitored with repeat hearing tests. Based on current research, clinicians may offer corticosteroids as initial therapy. This is most commonly given in pill form but can be done with an injection through the eardrum (intratympanic) for those patients for whom oral steroids are contraindicated. Although antivirals are commonly prescribed, there is insufficient evidence to support their effectiveness in treating sudden hearing loss. Hyperbaric oxygen may also be offered within 2 weeks of the initial diagnosis of SSNHL or up to 1 month in conjunction with steroids. Clinicians should offer salvage therapy (usually intratympanic steroids) for incomplete recovery after initial therapy. The benefits of therapy may include more prompt and complete recovery of hearing, but there are also side effects that must be considered when choosing among the available options. If the ABR is abnormal, good practice requires an MRI.
6. What are the side effects of each treatment?
   1. Side effects vary with each treatment modality but may include such things as increased anxiety, pain, dizziness, elevated blood sugar, elevated blood pressure, depression or insomnia. You should have a conversation with your provider regarding the specific side effects associated with your treatment.
7. What else can I expect?
   1. Sudden hearing loss can be frightening and may result in embarrassment, frustration, anxiety, insecurity, loneliness, depression and social isolation. Individual or group counseling can be helpful in supporting patients with SSNHL. Audiologic rehabilitation needs to be addressed as soon as the hearing loss is identified. This includes counseling and discussion of nonsurgical and surgical amplification and hearing restoration options. Clinicians should obtain follow up audiometry within 6 months of initial diagnosis of SSNHL.