Balance and Dizziness
Staying balanced is a complicated interaction between several different organs and body systems. Sensory inputs come from three main sensory systems:
- vestibular (the balance portion of the inner ear)
- proprioceptive (limb position) sensations.
The brain is the central processing centre for all three sources of balance information. It coordinates this information and helps you maintain your balance by guiding which muscles to use to keep good balance and clear vision.
Disruption to any of these three systems may result in abnormal or misinformation being sent to the brain. This can result in vestibular symptoms, such as false feelings of movement, vertigo, dizziness, imbalance, or falls. Thus dizziness can occur when sensory information is distorted or damaged. The brain’s influence on the body’s glands and muscles may also cause nausea, vomiting, or cold sweats. They may also influence neck and jaw (tempomandibular joint) symptoms.
When standing still it is normal to sway slightly. We avoid falling over because our brain constantly integrates vestibular, visual, and proprioceptive information. Impaired vestibular function can increase body sway and fall risk.
Some feelings of dizziness are related to conflicting sensory experiences between the three systems (vestibular, proprioceptive, and visual). Motion sickness, a malady that affects sea, car, and even space travellers, occurs when the brain receives conflicting sensory information about the body’s motion or position. For example, when someone reads while riding in a car, the inner ear senses the movement of the vehicle, but the eye gazes steadily on the book that is not moving. The resulting sensory conflict may lead to typical motion sickness symptoms such as dizziness, nausea, vomiting, and sweating.
A second form of motion sensitivity can occur when sitting still. Some people feel motion sick or dizzy watching an action movie or being in a busy environment such as a crowd or supermarket. This is sometimes referred to as ocular dizziness or visual vertigo.
Dizziness may also occur with repeated body movements or specific head/body movements. Yet another form of dizziness occurs when we turn in a circle quickly several times and then stop suddenly. This may occur due to changes in the endolymph or changes in the brain’s ability to deal with this information.
Another common symptom is visual blurring, in particular with quick or repetitive head movements.
Each form of dizziness or motion sensitivity requires a different rehabilitation approach, so it is important to describe in detail your specific symptoms with your physician(s) and your physical therapist so that your treatment plan is specific to you.