It is in the inner ear that sound is conducted to the central nervous system as acoustic (mechanical) energy is converted to electrochemical energy.  The inner ear (labyrinthine cavity) is a series of bony cavities which are filled with fluid.  The labyrinth includes the cochlea, vestibule, and semicircular canals.  The vestibulocochlear nerve (8th cranial nerve) is the primary nerve of the inner ear.

According to NMSS, hearing loss, or impaired hearing, is an uncommon symptom of MS affecting about 6% of people with MS.  As multiple sclerosis can cause lesions and disruptions of nerve signals along any nerve of the central nervous system including cranial nerves, it is not surprising that MS can affect hearing.  Hearing loss may be associated with other symptoms affecting vision, balance, and equilibrium which are controlled by the brainstem.  Deafness due to MS is very rare.  Since the trigeminal nerve is involved in hearing, I wonder if people who have trigeminal neuralgia also experience hearing loss.

In a future post, I will review what research there has been regarding hearing loss and MS.  A quick search reveals that there may be more information available than I was previously aware.  

Have you noticed changes in your hearing since developing MS?

RESOURCES:
Ear Anatomy - Medscape Reference.  Accessed February 14, 2013.

Hearing Loss - National MS Society.  Accessed February 14, 2013.

Lisa Emrich is author of the blog Brass and Ivory: Life with MS and RA and founder of the Carnival of MS Bloggers.