The Vestibular System
What are the symptoms of a vestibular disorder?
The vestibular system includes the parts of the inner ear and brain that help control balance and eye movements. If the system is damaged by disease, aging, or injury, vestibular disorders can result, and are often associated with one or more of these symptoms, among others:
Vertigo and dizziness
Imbalance and spatial disorientation
Cognitive and/or psychological changes
Vision is fundamental when it comes to maintaining our balance, (if you don’t believe us try standing on one foot with your eyes closed) and our vision system works with our balance centres in our ears to prevent us from falling over. Sometimes as the result of injury or infection this link can be lost or distorted. We have all probably experienced this as a temporary phenomenon in sea sickness.
This is an awful situation to be in as sufferers are sensitive to the least movement and can become dizzy and sick on a regular basis in response to simple things like standing up quickly or being in a lift.
Where appropriate we can work to re-establish the correct link between the ears and eyes and re-establish balance. One of our patients found she could walk without the support of her stick after only a few sessions. Where appropriate we can work to re-establish the correct link between ears and eyes and regain balance.
IT MOVED! Was it my eyes or did it really move?
One of the most common symptoms that we hear from patients is that they experience a sensation of movement. Whether it’s the words on the page that appear to move or the ground seems to be moving as they walk across it. It is a common complaint from patients with conditions as far apart as dyslexia and encephalitis.
There is an amazing mechanism combining what we see, our eye muscles and our ears to sort this out and determine whether, if something appeared to move or explain what actually happened.
Let us consider the three possibilities where movement is noted. Either the;
1. the object moved
2. the observer moved but the eyes stayed still
3. the observer and the object stayed still and the background moved
In (1) the image would be passed across the eye but there would have been no feedback from either eye muscles or the proprioception (movement and balance) system.
In (2) the proprioception system would provide the clue. There are two systems in the ears, the semi-circular canals which register on three planes, left and right, up and down, rolling (moving head from left to right shoulder and vice versa). the second detects changes in gravity, how you know you are going up or down in a lift. Eye muscles would have no input.
In (3) any instruction given to the eye muscles is accompanied by a reply from the muscle to tell the brain what has happened. Any damage or paralysis of an eye muscle, for example during surgery results in balance problems.
Where there is a fault with any of these systems then an imperfect feedback, for example, from of a muscle moves the eye but does not communicate the fact to the brain, will result in the brain becoming confused as to what information vision has just provided. People with dyslexic type symptoms often complain of words moving on the page and careful observation often reveals that the eye movements employed when reading are far from perfect. The subject is rarely aware that this happens although they may complain that their eyes feel funny or start to wander. Convergence issues are also a problem where the children find it difficult to team their eyes or keep them picked on the page.
I once heard an interview with an old Jazz Saxophonist who was being praised for the way his playing had improved despite his advanced years. He replied, “If you keep practising you’ve got to get better”
The vestibular system includes the parts of the inner ear and brain that process the sensory information involved with controlling balance and eye movements. If disease or injury damages these processing areas, vestibular disorders can result. Vestibular disorders can also result from or be worsened by genetic or environmental conditions, or occur for unknown reasons.
The most commonly diagnosed vestibular disorders include benign paroxysmal positional vertigo (BPPV), labyrinthitis or vestibular neuritis, Ménière’s disease, and secondary endolymphatic hydrops. Vestibular disorders also include superior semicircular canal dehiscence, acoustic neuroma, perilymph fistula, ototoxicity, enlarged vestibular aqueduct, migraine-associated vertigo, and mal de débarquement. Other problems related to vestibular dysfunction include complications from aging, autoimmune disorders, and allergies.
What about children?
TThe vestibular system might not be one of the five basic senses we were taught as children, but it is arguably the most fundamental sense. It is the first sensation a fetus experiences prior to birth and as our other senses develop, they in many ways depend on the vestibular system to integrate properly. Along with the cochlea of the auditory system, it comprises the labyrinth of the inner ear. Movement of the fluids in these semicircular canals inform us of changes in our head position, gravitational pull, and direction and speed of movement. The vestibular system signals to our other senses when it’s necessary to make adjustments so that we can maintain balance, clear vision, adequate muscle tone, and coordination.
Difficulties with vestibular processing can make many aspects of everyday life challenging. These children may appear lazy, hyperactive, clumsy, inattentive, impulsive, or anxious. Dysfunction can present as hypo or hyper responsive and, much like the other sensory systems, a child may exhibit behaviors of both.
Signs of difficulty with vestibular processing include:
Dislike/fear or craving/seeking out activities requiring feet to leave the ground such as swings, slides,
riding a bike, jumping or climbing
Clumsiness or frequent falling
Often moving slowly/cautiously
Frequent motion sickness/dizziness
Appearing to never become dizzy with excessive spinning
Seemingly unaware of danger/risks or impulsively jumping, running, and/or climbing
Appearing frequently “lost” in their environment or having difficulty locating objects
Dislike of being moved to stomach or back as a baby or having their head tilted back
Rocking, spinning, twirling, or frequent head tilting. May also intently watch moving objects
Often prefers sedentary activities
Difficulty sitting still or unable to sustain attention without moving
Difficulty with reading, writing, and/or math
Often slouches, holds head up with hands, or prefers lying down