According to Dr. A. Jean Ayres, author of “Sensory Integration and the Child,” the vestibular — or balance — sense tells a person where the body is in relation to gravity. It helps us respond to movement such as shifting weight to avoid falling. The vestibular system contributes to the brain’s ability to interpret visual information. Impairment may be demonstrated by eye movement and visual perceptual problems.
Significance of the Vestibular System
Just like other sense organs such as skin or eyes, the vestibular organs receive stimuli, in this case movement, send it to the brain to be interpreted and then use it during a response, such as jumping to catch a ball. The vestibular organ contains a very complex structure made of bone and soft tissue called the labyrinth. The labyrinth contains two types of vestibular receptors that take in sensory information during head movement and changes in speed. The National Institutes of Health reports that the vestibular system works with the visual system to maintain a steady focus on objects that are stationary or moving. The vestibular and visual systems work together so that objects do not look blurred as the head moves.
Types of Vestibular Disorders
Vestibular disorders can be congenital or the result of disease or injury. According to the Vestibular Disorders Association, symptoms can include vertigo, dizziness and balance problems. There are many pediatric conditions that can be associated with a vestibular problem, including developmental delays, visual perceptual impairments, seizures, dizziness, abnormal movement, sensitivity to movement, poor eye-hand coordination and nystagmus. Indiana-based optometrists Richard L. Windsor and Laura K. Windsor describe nystagmus as involuntary rhythmic shaking of the eyes, and report more than 45 types of nystagmus.
Diagnosing Vestibular Disorders
According to the Vestibular Disorders Association, vertigo — the sensation of spinning — can be diagnosed with tests that look at nystagmus. To diagnose a pediatric vestibular disorder, doctors perform many tests to rule out other causes of dizziness or balance problems such as infections or metabolic disorders. Vestibular symptoms related to developmental delays can also be evaluated by occupational therapists using the Sensory Integration and Praxis Test. The nystagmus subtest involves spinning a child seated on a rotary board and counting eye oscillations. The quality and duration of the eye movements provide diagnostic information to doctors and therapists.
Sensory Processing Disorders
Sensory processing disorders (SPD) also known as dysfunction in sensory integration (DSI) often involve inadequate vestibular processing that results in impaired eye movements and visual perceptual skills. Anne G. Fisher, Elizabeth A. Murray and Anita C. Bundy, authors of “Sensory Integration Theory and Practice,” report that the vestibular system has connections with eye muscles and that the vestibular, visual and body awareness senses together function to enable stabilization of the eyes in space during head movements. Eye movement disorders include impaired abilities to fixate or stabilize a gaze on an object, impaired visual tracking to follow a moving object and difficulties in coordinating smooth movements in looking from one object to another such as words on a page.
Treatment for Vestibular Disorders
Some vestibular disorders are treated with medication, surgery or vestibular rehabilitation therapy (VRT). According to the Vestibular Disorders Association, VRT is an exercise-based program. Occupational therapists treat children with vestibular-based sensory processing disorders by providing activities that promote an adaptive response such as improved eye-hand coordination from tossing bean bags at targets while moving on a swing.
References
- “Sensory Integration Theory and Practice”; Anne G. Fisher, Elizabeth A. Murray and Anita C. Bundy; 1991
- National Institute on Deafness and Other Communication Disorders: Balance Disorders
- Vestibular Disorders Association: About Vestibular Disorders
- Understanding Nystagmus
- The Vestibular System
