Manage vestibular-ocular and oculomotor conditions following head injuries

Most concussions are reported to occur in individuals in the 15-24 age group.^1,2 While statistics vary on the matter, estimations show concussions affect around 0.3-1% of the U.S. population yearly.

And that percentage, with variability depending on the region and referenced research study, may be roughly extrapolated to the global population.^3-6 Although it is often thought that sports accidents are the most likely culprit, motor vehicle accidents and falls cause more concussions than sports accidents. Of those individuals who experience an acute sports concussion, nearly 65% report vestibular or oculomotor symptoms. Even though the rate of recovery from a concussion for individuals 18 years and older is 10-14 days,⁷ individuals who have a premorbid vestibular or oculomotor dysfunction or experience symptom provocation with oculomotor examination tend to have a longer recovery time.

While exact percentages shift between studies, these statistics demonstrate that DCs, no matter their specialty, are likely to encounter concussions and coinciding vestibular-ocular (VO) conditions.⁸ A DC should understand how to screen for these conditions, and once these conditions are identified, the DC can determine what they can manage in the office and what requires co-management/referral. 

The vestibular-ocular specialist role

The role of the VO specialist is well-established in the treatment of dizziness and other associated symptoms. However, the increase in research surrounding concussions and coinciding VO conditions over the past 10 years demonstrates an increased awareness on the effect these conditions may have on the recovery of concussed individuals.⁹ This is not to say every primary care provider needs to be a VO specialist, but it suggests the need for primary care providers, which DCs are, to recognize these conditions and ensure they are treated appropriately. It can be challenging to determine the root cause of symptoms overlapping between vestibular, oculomotor, cervical and other systems, but there are a few basic tests that can help with the assessment of these symptoms. The Vestibular Ocular Motor Screening (VOMS) test battery, Head-Impulse-Nystagmus-Test-of-Skew (HINTS) and the King-Devick are three tests commonly incorporated in assessment of patients following a head injury that can help identify VO conditions. Benign paroxysmal positional vertigo (BPPV) is another condition that may occur coincidently. Otolith repositioning tests, including Dix-Hallpike and the Supine Roll Test, can help identify posterior versus horizontal canal disorders.  

The VOMS test battery involves testing near-point convergence, smooth pursuit, saccades, vestibular-ocular reflex and visual motion sensitivity. The HINTS test focuses on gaze fixation and differentiating between central and peripheral vestibulopathy. The VOMS has a high internal consistency (0.91-0.97) and requires little equipment other than a 14-point font movable target, such as a tongue depressor with an “X” on it. Dizziness, headache, fogginess and nausea are reported before and after each part of VOMS is completed. Discussion regarding the best scoring interpretation is ongoing, but a “positive” result is typically considered to be an increase of 2/10 or more for any symptom. If a patient experiences a positive test score, the provider should consider a trial of specific VO rehabilitation. 

Benign paroxysmal positional vertigo affects 64 of every 100,000 members of the general population, and symptoms related to BPPV are more common in individuals who experience a head injury. It is caused when an otolith becomes mispositioned in one of the semi-circular canals or cupulas, resulting in an altered sense of position that then causes vertigo. Of those diagnosed with BPPV, +/-80% have posterior canal involvement, +/-15% have horizontal canal involvement, and anterior canal conditions occur in 1-5% of those diagnosed. In brief, positive findings on a Dix-Hallpike would indicate treatment via Epley’s maneuver for a posterior canal malposition. The Supine Roll Test screens for a horizontal canal condition that may be treated with the Lempert or the BBQ Roll Maneuver. Maneuvers for diagnosing and treating anterior canal conditions exist, but due to their rare and challenging nature it is often best to refer any suspected anterior canal conditions to a specialty clinic. These tests and treatments are a brief summary of the conditions, and these conditions should be managed by a provider versed in their interpretation and implementation. 

Final thoughts

DCs, or any primary care providers, cannot expect to specialize in or manage every condition that presents itself in their office. However, we must be aware of conditions that may mimic other commonly encountered conditions.¹⁰ Understanding how to differentiate between concussions and common VO conditions is beneficial to ensuring your patients are receiving the proper care for their condition. If the patient’s condition is not responding to the DC’s treatment, or the DC would rather have a specialist treat aspects of the injury, it is critical the DC understands to what specialist the patient should be referred to ensure the patient does not have prolonged symptoms. Regarding VO conditions, DCs should research VO specialists in their area (these may be other DCs, PTs, OTs or similar providers), visit their clinics, discuss how the referral/co-management process would best be managed and establish a fluent referral process. 

JORDAN KNOWLTON-KEY, DC, MS, EMT, CCSP, ICSC, serves as the chiropractic sports physician at the Lake Placid United States Olympic and Paralympic Training Center, where he works primarily with biathlon, bobsled/skeleton and luge athletes. His passion for sports chiropractic and adventure sports led him to pursue several additional degrees/certificates so he could follow patients through each step of their recovery. He possesses a Master of Exercise Science degree, an EMT license, certification as an Alpine Ski Patroller, certification as a Diplomate of the American Chiropractic Board of Sports Physicians®, and certification as an International Certified Sports Chiropractic and Certified Strength and Conditioning Specialist. He can be reached at drjordanknowltonkey@gmail.com or peaksportschiropractic.com for questions/inquiries. 

References

1. Thomas DG, et al. Implementation of active injury management (AIM) in youth with acute concussion: A randomized controlled trial. Contemporary Clinical Trials. 2022;123:106965. Science Direct. https://www.sciencedirect.com/science/article/abs/pii/S1551714422002919?via%3Dihub. Accessed April 9, 2024. 
2. Hon KL, et al. Concussion: A Global Perspective. Seminars in Pediatric Neurology. 2019;30:117–127. Science Direct. https://www.sciencedirect.com/science/article/abs/pii/S1071909119300257?via%3Dihub. Accessed April 9, 2024. 
3. Schroeder T, et al. Nonfatal traumatic brain injuries from sports and recreation activities; United States, 2001–2005. Morbidity and Mortality Weekly Report. 2007;56(29):733–737. CDC. https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5629a2.htm. Accessed April 9, 2024. 
4. Cassidy JD, et al. Incidence, risk factors and prevention of mild traumatic brain injury: results of the WHO Collaborating Centre Task Force on Mild Traumatic Brain Injury. J Rehabil Med. 2004;43:28-60. PubMed. https://pubmed.ncbi.nlm.nih.gov/15083870/. Accessed April 9, 2024. 
5. CDC Announces Updated Information to help Physicians Recognize and Manage Concussions Early. CDC Newsroom. [Press Release]. June 7, 2007. https://www.cdc.gov/media/pressrel/2007/r070607.htm. Accessed April 9, 2024. 
6. Langer L, et al. Increasing Incidence of Concussion: True Epidemic or Better Recognition? Journal of Head Trauma Rehabilitation. 2020;35(1):E60-E66. https://journals.lww.com/headtraumarehab/Abstract/2020/01000/Increasing_Incidence_of_Concussion__True_Epidemic.16.aspx. Accessed April 9, 2024. 
7. Mucha A, et al. A brief vestibular/ocular motor screening (VOMS) assessment to evaluate concussions: Preliminary findings. American Journal of Sports Medicine. 2014;42(10):2479–2486. PubMed. https://pubmed.ncbi.nlm.nih.gov/25106780/. Accessed April 9, 2024. 
8. Han BI, et al. Vestibular rehabilitation therapy: Review of indications, mechanisms, and key exercises. Journal of Clinical Neurology. 2011;7(4):184–196. Korean Neurological Association. PubMed. https://pubmed.ncbi.nlm.nih.gov/22259614/. Accessed April 9, 2024. 
9. Alsalaheen B, et al. Changes in vestibular/ocular-motor screen scores in adolescents treated with vestibular therapy after concussion. Pediatric Physical Therapy. 2020;32(4):331–337. PubMed. https://pubmed.ncbi.nlm.nih.gov/32773522/. Accessed April 9, 2024. 
10. Patricios JS, et al. Consensus statement on concussion in sport: The 6th International Conference on Concussion in Sport–Amsterdam, October 2022. British Journal of Sports Medicine. 2023;57:695-711. PubMed. https://pubmed.ncbi.nlm.nih.gov/37316210/. Accessed April 9, 2024.