Idiopathic Sudden Sensorineural Hearing Loss (ISSNHL) is an instant hearing loss whithout apparent cause. The etiology is unknown, we can only make assumptions. In some cases the cause is an autoimmune disease of the cochlea. In many cases the cause is a vascular injury or a viral disease. Affected are people with an average age between 40 and 60 years old, or older. A commonly used criterion to define this disease is a sensorineural hearing loss of greater than thirty dB over three pure tone frequencies. The disease manifests itself quickly, less than three days. Usually it presents as unilateraly hearing loss. The search for the hearing threshold is always the first step for diagnosis of ISSNHL.


Idiopathic Sudden Sensorineural Hearing Loss has 4 theoretical pathways.
- Cochlear viral infection
- Cochlear (or labyrinthine) vascular compromise
- Intracochlear membrane ruptures
- Immune mediate inner ear disease (Cogan syndrome). 

There aren't sex differences.
It 'important to distinguish Sensorineural Hearing Loss (SNHL) from Conductive Hearing Loss (CHL). 

 

audiogram sudden deafness

Example of Idiopathic Sudden Sensorineural Hearing Loss (ISSNHL). Man, 64 year old. The left ear showed a severe sensorineural hering loss. The audiometric configuration was more serious for the higher frequencies. His ability to understand speech was preserved. Hearing in the right ear was within normal limits.
This patient was treated with orally corticosteroids.

The following diseases have been associated with Idiopathic Sudden Sensorineural Hearing Loss (ISSNHL).
- Inflammation: Sarcoidosis, Wegener granulomatosis, Cogan syndrome.
- Bacterial infection (eg, meningitis, vasculitis, shyfilis)
- Viral infection (eg. cytomegalovirus,)
- Hypercoagulable states (eg, Waldenstrom macroglobulinemia)
- Tumors (eg, Vestibular schwannoma, temporal bone metastases, other cerebellopontine angle tumors, cholesteatoma of the temporal bone)
- Postradiation therapy 
- Ototoxic drugs 
- Trauma (eg. temporal bone fractures, acute acoustic trauma )

 

References
Halpin C, Rauch SD. Steroid therapy for sudden sensorineural hearing loss. Hear Rev - 2003; 10: 32-35.

Chen C, Halpin C, Rauch SD.  Oral steroid treatment for sudden sensorineural hearing loss: a ten-year retrospective analysis. Oto Neurotol 2003; 24:728-733. 

See also:

- The headache

- Vertigo, imbalance and dizziness

- Remove ear wax 

- Malignant External Otitis 

- Cochlear implant - course G.B. Mangioni Hospital, Lecco

Otolaryngology and Head and Neck Surgery
Carlo Govoni performs surgery ENT at the nursing home in Columbus Clinic Center, via Buonarroti, 48 Milan; G.B. Mangioni Hospital, via Leonardo da Vinci 49, Lecco and Hesperia Hospital, via Arquà, 80 - Modena.  Another ambulatory is located in MILAN, Magenta road, civic number 64 - phone:  (+39) 0258103023 and LINEA MEDICA, San Giuliano Milanese phone (+39) 0239297650.

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