Dizziness & Vestibular System
The human body maintains balance and posture through feedback from 3 systems: the somatosensory, visual and vestibular system. The vestibular system is responsible for maintaining balance and spatial orientation and includes parts of the inner ear and the brain.
Dizziness as it relates to physical therapy stems from issues in the upper neck and/or the vestibular system. It is estimated that approximately about forty five percent of the people seek medical help for dizziness. Two-thirds of these cases happen to be dizziness related to problems with the vestibular apparatus, which is located in your inner ear that plays a crucial role in our ability to stand, walk, and maintain postural stability.
Causes of Vestibular System Dysfunction
The vestibular system can become dysfunctional from either peripheral causes or central causes.
Peripheral causes include dysfunction of the vestibular apparatus and the vestibular nerve due to factors such as age, drug toxicity, trauma, labyrinthitis and vestibular neuritis.
Central causes can occur due to dysfunction of the vestibular nuclei in the brainstem and its connections, from decrease in or lack of blood supply or bleeding of the blood vessels supplying these nerves and the cerebellum. Tumor can also lead to vestibular symptoms.
Symptoms experienced due to vestibular dysfunction includes:
Dizziness: A sensation of unsteadiness or lightheadedness.
Vertigo: A feeling that you or your surroundings are spinning or moving when they are not.
Imbalance: Difficulty maintaining an upright posture and a tendency to fall.
Nausea: Sensation of throwing up, often accompanied by dizziness or vertigo.
Visual disturbances: Blurred vision, difficulty focusing, or sensitivity to light.
Tinnitus: sensation of ringing in ears
The peripheral symptoms are the resultant of (i) decreased function of the vestibular apparatus or (ii) distortion in the transduction of vestibular stimulus. The former causes symptoms as mentioned previously due to issues with the vestibulo-ocular reflex and vestibulo-spinal reflex. However, the latter causes movement-induced vertigo as in benign paroxysmal positional vertigo (BPPV).
While some of the peripheral causes can be amenable to physical therapy treatment, the central causes cannot, thus requiring medical intervention.
Vestibular Rehabilitation Therapy [VRT]
Vestibular Rehabilitation Therapy is a customized program of balance retraining and habituation exercises designed to reduce vertigo and dizziness, gaze instability, and/or imbalance and falls. The treatment for reduced vestibular function is vestibular rehabilitation, while the treatment for distortion in the vestibular stimuli entails canalith repositioning maneuver.
Prior to beginning a vestibular rehabilitation program, a thorough screening is done to find the different systems influencing the person’s dysfunction. If the person suffered from trauma, the neck needs to be screened for any issues with vascular or neurological compromise as well as for neck stability. Ocular alignment, voluntary eye movements and VOR are checked to see if there is any issue with visual acuity. Finally, the person’s balance, both static and dynamic and its influence on dizziness is assessed.
Rehabilitation is based on the above findings. They could be:
Adaptation: this involves in the re-training of the VOR and VSR to improve both gaze and postural stability.
Habituation: the goal is to reduce the body’s response to a stimulus that provokes the person’s symptoms
Substitution: this involves teaching the person to rely on other two systems of balance namely, the visual and somatosensory components.
Canalith Repositioning Maneuvers: this is done to reposition the calcium crystals from the semicircular canals into the utricle to reduce movement induced vertigo.
Manual therapy: hands-on approach to treat any dysfunction of the upper cervical spine.
Vestibular rehabilitation has proven to be highly effective in improving the quality of life for individuals suffering from vestibular disorders. It not only helps alleviate immediate symptoms but also enhances the patient’s long-term ability to engage in everyday activities safely and confidently. By addressing the root cause of vestibular problems and providing targeted interventions, vestibular physical therapy empowers individuals to regain their equilibrium and lead more fulfilling lives.