March 8, 2020
vestibular rehab after concussion

Role of Vestibular Rehab in Concussion Management

As sports medicine physicians, we are tasked with the role of evaluating risk factors and symptoms that may delay a patient’s recovery from a concussion. Researchers have identified that vestibular deficits are commonly seen in the post concussive period (Anne Mucha, 2014). Patients typically complain of dizziness and vertigo (James Gurley, 2013). The forces experienced in the brain during a concussion can directly affect the vestibular system (Kath Aligene, 2013).
There are two units that make up the vestibular system. These are the vestibule-ocular system and vestibule-spinal system (Anne Mucha, 2014). The peripheral component of the vestibular system includes the semicircular canals, otoliths, vestibular ganglia and nerve (Kath Aligene, 2013). The central components of the vestibular system include the cerebellum, thalamus, cerebral cortex, and vestibular nuclei (Kath Aligene, 2013). Studies suggest that the peripheral system is more affected in concussions than the central components (Kath Aligene, 2013).
There are high rates of vestibular dysfunction in concussed athletes. A retrospective study performed at the Children’s Hospital of Philadelphia looked at patients referred to their sports clinic diagnosed with a concussion and evaluated them for vestibular symptoms. What they found was that 81% of their patients were found to have either a positive vestibulo-ocular reflex or abnormal tandem gait compared to only 0.5% of a general pediatric population (Daniel Corwin, 2015).
Many studies have looked to see if vestibular rehab serves a role in rehabilitating the concussed athlete. In 2014 published in the British Journal of Sports Medicine, physicians in Calgary looked to see if PT that included vestibular rehab and cervical spine exercises would reduce the time to return to play (Kathryn J Schneider, 2014). What they found was that after 8 weeks, the intervention group had a higher proportion of participants being cleared to return to play (Kathryn J Schneider, 2014).

Image 1. Demonstration of the head impulse test (courtey of link.springer.com)

Identifying vestibular dysfunction in concussions can be challenging. There are multiple physical exam tests to help diagnose vestibular dysfunction. The impulse head thrust test helps discriminate between peripheral and central causes of vertigo (Chilstrom, 2019). What makes the head impulse test difficult to interpret is that a normal exam suggest a central lesion. For example, when the patient’s head is quickly rotated to the right, the patient is able to keep their eyes fixated on the provider (Chilstrom, 2019). However, an abnormal test, which suggests a peripheral lesion, is found when the patient cannot keep their eyes fixed on the provider and they have a corrective saccade as the patient attempts to re-focus on provider (Chilstrom, 2019).
In 2014 published in the American Journal of Sports Medicine, the Vestibular/Ocular Motor Screening Assessment was evaluated as a tool to identify vestibular and ocular symptoms secondary to concussion (Anne Mucha, 2014). They found that patients who had been diagnosed with a concussion had higher VOMS scores than the control group (Anne Mucha, 2014). Further studies have been done which show concussions lead to impairments of the vestibular ocular reflex (James Gurley, 2013).
Another physical exam test commonly used is the Romberg test, which helps identify intracranial lesions and proprioceptive problems. A patient first stands with their two feet together, eyes open, and arms on their side (Magee, 2014). The patient then closes their eyes and the provider evaluates for any loss of balance or falls (Magee, 2014).
modified bess concussion vestibular rehab

Image 2. Demonstration of the modified BESS (courtesy of tekscan.com)

A Balance Error Scoring System can also be used to assess postural deficits post concussion (WG Wright, 2017). Patients are taken through three positions, which include double-leg stance, single-leg stance, and tandem stance (Brian Moore, 2020). The assessment is done on a firm surface and then again on a foam surface (Brian Moore, 2020). The amount of errors the patient makes are then totaled to a maximum of 60 (Brian Moore, 2020).

Image 3. Demonstration of vestibular ocular motor screening tool (courtesy of UPMC)

The vestibular/ocular motor screening tool is another test used to detect changes in the vestibule-ocular system and with ocular eye movements (Brian Moore, 2020). Patients are asked if symptoms are provoked during smooth pursuit, horizontal saccades, vertical saccades, horizontal and vertical vestibule-ocular reflex, visual motion sensitivity, and near point convergence (Brian Moore, 2020).
The goal of vestibular rehab is to improve symptoms of dizziness and improve the patient’s balance (James Gurley, 2013). Principles of vestibular rehabilitation are to facilitate neural plasticity within healthy neural systems to help overcome the deficits experienced from a concussion (Kath Aligene, 2013). Vestibular rehab helps overcome deficits in the ability to keep focus on an object with the head in motion (James Gurley, 2013). This process, known as dynamic gaze stability, relies on the vestibular ocular reflex, cervical ocular reflex, and the visual system (James Gurley, 2013). Exercises focus on three mechanisms: habitation, adaption, and substitution.
Habituation exercises involve repeating provoking stimuli or head movements to cause a reduction in pathologic response to the stimuli (Kath Aligene, 2013). Habituation exercises are preferred when the primary deficit is impaired visual motion sensitivity (Kath Aligene, 2013). For example, a movement is done and repeated until the symptoms resolve (Kath Aligene, 2013). The repeated exposure of a provoking stimuli helps habituate the abnormal visual response (Steven Broglio, 2015). This needs to be done in a stepwise fashion to avoid symptom exacerbation (Steven Broglio, 2015).

Image 4. Demonstration of habituation therapy (courtesy of entandaudiologynews.com)

Adaptation exercises focus on assisting the central nervous system to overcome the change experienced within the vestibular system (Kath Aligene, 2013). Adaptation exercises are preferred when the patient has an impairment in convergence and vestibule-ocular reflex (Kath Aligene, 2013). The primary focus is on the retinal slip that occurs during head movement (Kath Aligene, 2013). One adaptation exercise is having the patient move their head from side to side and having them keep their eyes on a nonmoving object (Kath Aligene, 2013). As symptoms improve, the speed that the patient moves their head can be increased (Kath Aligene, 2013). The patient can be further challenged by having them maintain eye contact on an object while changing object size, velocity, and direction (Steven Broglio, 2015).
Substitution exercises aim to overcome impaired vestibular processes by teaching the patient alternative strategies (Kath Aligene, 2013). Substitution exercises are used for major vestibular dysfunction (Kath Aligene, 2013). This can include having the patient direct their eyes towards a target prior to moving their head (Kath Aligene, 2013).
Another principle of vestibular rehab is a graded aerobic exercise program. An exercise program can improve balance through muscle conditioning and also improve postural control, which is also affected in concussion (Kath Aligene, 2013; Steven Broglio, 2015). Dr. Leddy at the University of Buffalo published about sub-symptom threshold exercise in Clinical Journal of Sports Medicine in 2011. This was the first evidence that showed that sub-symptom threshold exercise led to an improvement of symptoms in concussed patients (John Leddy, 2010). Different protocols for postural control have also been studied, which have patients walk with their eyes closed, walking on soft surfaces, and also walking up and down stairs (Gottshall, 2011).
Overall, the detection of deficits in the vestibular and ocular system can help guide an athlete’s return to competition after experiencing a concussion. There are multiple physical exam tools and computer guided detection tools available to detect impairments in the vestibule-ocular system. The advancements in vestibular rehab should help athlete’s overcome these impairments in a safer and quicker fashion.

References

Anne Mucha, M. C. (2014). A Brief Vestibular/Ocular Motor Screening (VOMS) Assessment to Evaluate Concussions. American Journal of Sports Medicine, 2479-2486
Brian Moore, N. M. (2020). Concussion. In S. R.-G. Rolando Lazaro, Umphred’s Neurological Rehabilitation (pp. 674-722). St. Louis: Elsevier.
Chilstrom, M. (2019). Special Neurologic Tests and Procedures. In C. C. James Roberts, Roberts and Hedges’ Clinical Procedures in Emergency Medicine and Acute Care (pp. 1281-1293). Philadlephia: Elsevier.
Daniel Corwin, D. W. (2015). Vestibular Deficits following Youth Concussion. The Journal of Pediatrics, 1221-1225.
Drew Murray, D. M. (2017). Can vestibular rehabilitation exercises help patients with concussion? A systematic review of efficacy, prescription, and progression patterns. British Journal of Sports Medicine, 442-451.
Gottshall, K. (2011). Vestibular rehabilitation after mild traumatic brain injury with vestibular pathology. NeuroRehabilitation, 167-171.
James Gurley, B. J. (2013). Vestibular rehabilitation following mild traumatic brain injury. NeuroRehabilitation, 519-528.
John Leddy, K. K. (2010). A Preliminary Study of Subsymptom Threshold Exercise Training for Refractory Post-Concussion Syndrome. Clinical Journal of Sports Medicine, 21-27.
Kath Aligene, E. L. (2013). Vestibular and balance treatment of the concussed athlete. NeuroRehabilitation, 543-553.
Kathryn J Schneider, W. H. (2014). Cervicovestibular rehabilitation in sport-related concussion: a randomised controlled trial. British Journal of Sports Medicine , 1294-8.
Magee, D. (2014). Head and Face. In D. Magee, Orthopedic Physical Assessment (pp. 84-147). Elsevier.
Steven Broglio, M. C. (2015). Current and Emerging Rehabilitation for Concussion. Clinics in Sports Medicine, 213-231.
WG Wright, R. T. (2017). Visual-vestibular processing deficits in mild traumatic brain injury. Journal of Vestibular Research, 27-37.