Experiencing dizziness or problems with balance are very common complaints. There are a vast number of causes of dizziness or imbalance, including: cardiovascular, neurological, anxiety/depression, vision changes, head and/or neck trauma, medication, deconditioning and aging, infection, and dysfunction in the vestibular system (inner ear).
If you have any sudden onset of new dizziness, we advise you to speak to your physician first to rule out any serious causes of symptoms.
Once cleared medically, your doctor may refer you to physiotherapy to help manage or improve symptoms. The physiotherapist will do an assessment, and decide on a course of treatment. This involves evaluating standing and walking balance, checking the sensation and strength of the lower body, looking at how well the eyes and inner ear communicate with each other about where the body is in space, evaluating if certain positions of the head or body elicit the dizziness, and making sure the neck is strong and mobile. If the physiotherapist decides that the symptoms are due to a dysfunction of your vestibular system, you will begin the course of vestibular rehabilitation
What is the vestibular system?
The vestibular system is divided in two parts: the peripheral vestibular system and the central vestibular system. The peripheral vestibular system consists of the labyrinth, which holds 3 semicircular canals and two otoliths, and the nerves that carry the signals to and from the labyrinth. The peripheral system is responsible for detecting movement of the head and body, and relaying this information up to the central vestibular system, which consists of the processing centres of the brain (the vestibular nuclear complex and the cerebellum). The peripheral vestibular system senses rotation, linear acceleration, and position relative to gravity. It sends the information it picks up to the processing centres where, along with information from your vision centres and body position sensors, the brain can make incredibly fast decisions on how to move the eyes, head, and body, in order to stay balanced, have stable vision, and move in an unpredictable environment.
When something goes wrong with the vestibular system in particular, a common complaint is vertigo. The definition of true vertigo is: an illusion of movement in the environment (when none is actually happening). Other symptoms that occur when the vestibular system is dysfunctional are: unsteady gait, imbalance, and abnormal vision. The physiotherapist will ask specific questions about your symptoms, to better identify what the potential cause of your dizziness or imbalance may be.
Physiotherapists must have specialized training to recognize and treat specific vestibular dysfunctions/disorders such as:
- Benign Paroxsymal Positional Vertigo (BPPV): Crystals that normally sit on the otoliths enter into the canals, causing signal confusion between the inner ear receptors and the eyes/other balance centres in the body. Certain movements or positions of the head will trigger severe dizziness that lasts a few minutes. This is due to a delayed motion of these foreign crystals in the canals, making it seem to the inner ear that movement is ongoing, even though your eyes and body’s position receptors know the body is still. The brain triggers your eyes to move as if the head were rotating, and this causes the feeling of the room spinning. If your physiotherapist suspects BPPV, they will treat using certain standardized manoeuvres to reposition the crystals.
- Vestibular neuritis/labyrinthitis: This often occurs as a result of infection or inflammation of the nerve supplying the inner ear, or the inner ear itself. The signals coming from the affected ear don’t match the unaffected side, leading to confusion in the brain’s processing centre and triggering dizziness, nausea, and poor balance. Once the acute infection or inflammation is dealt with (ie: medical management), physiotherapy can help to re-train the vestibular system to become more efficient, and regain its previous capacity.
- Vestibular degeneration/trauma: Progressive or traumatic damage to the vestibular system changes how the signals about environment are perceived and interpreted. The physiotherapist can help to train other components of the balance system, and help to encourage as much rehabilitation of the injured system as is possible. (Also look for our upcoming blog post on Concussion Management with Physiotherapy in early 2018).