Vestibulocochlear dysfunction progressive familial

# Overview
Vestibulocochlear dysfunction progressive familial, known also as familial progressive vestibulocochlear dysfunction is an autosomal dominant disease that results in sensorineural hearing loss and vestibular areflexia.  Patients report feelings of vague dissiness, blurred vision, dysequilibrium in the dark, and progressive hearing impairment.

# Symptoms
Reported symptoms include:
- Sensorineural hearing loss
- Vestibular areflexia
- Hearing impairment
- Vertigo
- Nausea and vomiting
- Head movement-dependent oscillopsia

# Cause
The disease is an inherited autosomal dominant disease, but the physiological cause of the dysfunction is still unclear. An acidophyllic mucopolysaccharide-containing substance was discovered, especially in cochleas, Otolithic organs|maculas, and crista ampullaris of patients with DFNA9 (a chromosome locus), as well as severe degeneration of vestibular and cochlear sensory axons and dendrites. It is suggested that the mucopolysaccharide deposit could cause strangulation of nerve endings.
The Otolithic organs|maculas and crista ampullaris are what allow for non-visual sensation of head movements.  The crista ampullaris resides in the semicircular canals of the inner ear and detects angular acceleration, while the maculas are housed within the vestibule of the inner ear and detect linear acceleration.  When affected, these organs can lead to vertigo and nausea because the body would always feel off-balance.
-  Verhagen, Wim (7 July 2000). "Familial Progressive Vestibulocochlear Dysfunction Caused by a COCH Mutation (DFNA9)". Archives of Neurology. 57: 10451047. doi:10.1001/archneur.57.7.1045. Retrieved 9 December 2011. Unknown parameter |coauthors= ignored (help).mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
-  Verhagen, Wim (7 July 2000). "Familial Progressive Vestibulocochlear Dysfunction Caused by a COCH Mutation (DFNA9)". Archives of Neurology. 57: 10451047. doi:10.1001/archneur.57.7.1045. Retrieved 9 December 2011. Unknown parameter |coauthors= ignored (help)
-  Verhagen, Wim (7 July 2000). "Familial Progressive Vestibulocochlear Dysfunction Caused by a COCH Mutation (DFNA9)". Archives of Neurology. 57: 10451047. doi:10.1001/archneur.57.7.1045. Retrieved 9 December 2011. Unknown parameter |coauthors= ignored (help)
-  Saladin, Kenneth (2012). Anatomy and Physiology: The Unity of Form and Function. New York, NY: McGraw-Hill. pp. 596609. ISBN 978-0-07-337825-1.