By Karolina Kozlova, PT, DPT, Neurologic Clinical Specialist
What is a peripheral vestibular hypofunction (PVH)?
PVH is a term that refers to your inner ear balance system that lies outside of your central nervous system (brain and spinal cord) but is not functioning or under functioning from its normal. In each inner ear, there is a small system called the vestibular organ that communicates with the processing center (your brain) via a nerve that sends information about body movements and positions. When it’s not working properly, you may experience dizziness or vertigo, poor balance and/or blurry vision with head turns, difficulty walking (outdoors, dark rooms, crowded spaces), and nausea/vomiting.
What causes a PVH?
The most common cause of a unilateral hypofunction is a viral or bacterial infection that attacks the nerve going from your vestibular organ to the brain causing it to become inflamed – this is diagnosed as vestibular neuritis or labyrinthitis (if hearing symptoms are present). The inflammation interferes with signals (vestibular organ <-> brain) triggering dizziness, nausea, and vertigo. Research also indicated that PVH can be caused by auto-immune deficiencies or blood clots.
When both inner ear systems are affected, this is known as bilateral vestibular hypofunction. This occurs due to either sequential neuritis’s or from antibiotics used to treat the infections. Antibiotics such as Gentamycin, which are used to treat more serious infections, can cause ototoxicity (drug/chemical related damage) of the inner ears and results in damage to both balance systems.
Diagnosis/functional limitations summary
Diagnostic criteria for vestibular hypofunctions must be confirmed with vestibular function laboratory testing (caloric or rotational chair testing).
Physical therapy is a safe and effective movement-based approach to treat symptoms of vestibular hypofunctions and promote faster recovery. In order to prescribe exercises, the therapist will do an individualized and complete examination of your peripheral vestibular system and assess: vision, balance, walking and activities with which you have difficulty with.
Recommended activity levels/Precautions/Research
Research indicated that these conditions can be remedied whether in the acute, subacute and chronic stages, especially to address impairments and functional limitations related to vestibular deficits. If your imbalance is significant, it is important to take safety measures not to fall, this is especially important if you are older.
Types of exercises that will be addressed with therapy
During vestibular therapy, there will be a combination of four different exercise components to address impairments and functional limitations uncovered during evaluation. These include: exercise to promote gaze stability, habituate symptoms (optokinetic exercises), improve balance and gait and promote walking for endurance.
Summary of progression/therapy expectations/outcomes
Vestibular therapy is administered 1-2x/week in the clinic up to 3-4 months but requires a daily commitment from patients. Length of treatment will depend on the stage of hypofunction as well as functional gains and reduction in symptoms. Currently, research supports that patients perform exercises a minimum of 3 times per day for a total of 12-20 minutes. During your plan of care, your vestibular therapist will re-evaluate you periodically to make sure that you are making progress and will explain all findings. Once there is resolution of symptoms, a plateau in progress, or the set goals have been achieved, your skilled therapy can be discontinued.