Balance and Usher syndrome
About the human balance system
This system is the coordination of information from three sources in your body. These sources are:
1.Your visual system
2.Your vestibular system (this is information from the balance and orientation components in your inner ear)
3.Your proprioceptive system (this is information about the position of your feet, limbs and joints)
Balance and Usher
An individual with Usher's balance can can be affected by issues with two sources of the balance system - the vestibular and vision systems.
The vestibular system
The vestibular system is within the ear and consists of a series of fluid-filled canals set at different angles. When the head moves, the rolling fluid tells the brain exactly how far, how fast and in what direction the head is moving, by relaying the information down the vestibular nerve. If the brain knows the position of the head, it can work out the position of the rest of the body. When the vestibular system does not work the brain actually works hard to compensate for the loss in a number of ways, including making greater use of other senses.
Usher type 1
People with Usher type 1 have issues with balance, primarily because the vestibular system does not work (vestibular dysfunction) from birth. Consequently, babies with Usher type 1 may demonstrate delays in sitting and walking. The visual impairment associated with Usher type 1 then further impedes good balance, especially at night or in poor lighting conditions.
Usher type 2
Usher type 2 is not associated with vestibular dysfunction, meaning that balance should be similar to that of people without Usher. However, the visual impairment means there may be some lesser issues with balance, especially at night or in poor lighting conditions.
Usher type 3
Some people with Usher type 3 experience some balance issues as a result of vestibular dysfunction but not all do. It is currently thought that any dysfunction occurs later in life. As with Usher type 2, people with Usher type 3 may experience some problems with balance as a result of their visual impairment, especially at night or in poor lighting conditions.
The combination of tunnel vision and night blindness with vestibular dysfunction may make individuals with Usher syndrome more prone to accidental injury.
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Created: February 2016
Review due: February 2018
First published: Wednesday 2 December 2015
Updated: Thursday 4 February 2016