Abstract
Background
After concussion many people have cervicogenic headache, visual dysfunction, and vestibular deficits that can be attributed to brain injury, cervical injury, or both. While clinical practice guidelines outline treatments to address the symptoms that arise from the multiple involved systems, no preferred treatment sequence for post-concussion syndrome has emerged.
Purpose
This study sought to describe the clinical and patient-reported outcomes for people with post-concussion symptoms after a protocol sequenced to address cervical dysfunction and benign paroxysmal positional vertigo within the first three weeks of injury, followed by integrated vision and vestibular therapy.
Study Design
Retrospective longitudinal cohort analysis
Methods
Records from a concussion clinic for 38 patients (25 male 13 female, aged 26.9±19.7 years) with post-concussion symptoms due to sports, falls, assaults, and motor vehicle accident injuries were analyzed. Musculoskeletal, vision, and vestibular system functions were assessed after pragmatic treatment including early cervical manual therapy and canalith repositioning treatment—when indicated—integrated with advanced vision and vestibular rehabilitation. Patient-reported outcomes included the Post-Concussion Symptom Scale (PCSS) for general symptoms; and for specific symptoms, the Dizziness Handicap Index (DHI), Convergence Insufficiency Symptom Scale (CISS), Activities-specific Balance Confidence scale (ABC), and the Brain Injury Vision Symptom Survey (BIVSS). Paired t-tests with Bonferroni correction to minimize familywise error (p<0.05) were used to analyze the clinical and patient-reported outcomes.
Results
After 10.4±4.8 sessions over 57.6±34.0 days, general symptoms improved on the PCSS (p=0.001, 95%CI=12.4-30.6); and specific symptoms on the DHI (p<0.001, 95%CI=14.5-33.2), CISS (p<0.002, 95%CI=7.1-18.3), ABC (p<0.024, 95%CI=-.3 - -.1), and BIVSS (p<0.001, 95%CI=13.4-28.0). Clinical measures improved including cervical range-of-motion (55.6% fully restored), benign paroxysmal positional vertigo symptoms (28/28, fully resolved), Brock string visual convergence (p<0.001, 95%CI=3.3-6.3), and score on the Balance Error Scoring System (p<0.001, 95%CI=5.5-11.6).
Conclusion
A rehabilitation approach for post-concussion syndrome that sequenced cervical dysfunction and benign paroxysmal positional vertigo treatment within the first three weeks of injury followed by integrated vision and vestibular therapy improved clinical and patient-reported outcomes. Level of Evidence: 2b
Keywords: vestibular rehabilitation, vision therapy, manual therapy, cervicogenic headache, concussion
Introduction
Sport and recreation-related concussion is a rapidly growing problem, with an estimated 1.6-3.8 million people affected per year.1 Concussion also affects people involved in transportation accidents, fall-related injuries, and other trauma.1 Defined as a mild traumatic brain injury induced by direct or indirect biomechanical forces, concussion may or may not include loss of consciousness.2 While more than 80% of adults recover from sports-related concussions in 7-10 days, concussive symptoms can persist much longer and take weeks or months to resolve after injury.3,4 Symptoms lasting longer than the generally accepted three-week period can be referred to as protracted concussion recovery,3 a particular problem among adolescent athletes.5 After concussion in adolescents, protracted recovery is common with most reporting symptoms lasting more than a month: boys averaging seven weeks and girls an even longer 10 weeks.5
The signs and symptoms observed in protracted concussion recovery cannot always be linked to abnormal brain imaging or neuropathological changes, but rather are often attributed to multiple physiologic systems.6 Typical findings involve the musculoskeletal, visual, vestibular, cardiovascular, and autonomic systems.4 Signs and symptoms after concussion attributed to the musculoskeletal system are commonly localized to the cervical region and include joint and myofascial hypomobility that limits range-of-motion (ROM)7 and cervicogenic headaches.6 Cervicogenic headaches are secondary headaches encompassing neck or facial pain associated with bony, myofascial, and disc disorders of the cervical spine.8 Cervicogenic headaches develop with the onset of cervical disorders, such as biomechanical forces occurring during mild traumatic brain injury, and significantly improve with the resolution of cervical disorders.8 Visual or oculomotor symptoms are not limited to but commonly include blurred vision, double vision, difficulty concentrating, and difficulty with activities such as reading.3 Vestibular system symptoms include dizziness, nausea, fatigue, balance difficulties, and blurry vision with head movements known as oscillopsia.9 In addition, final clinical recovery can be delayed by dysautonomia that can decrease exercise tolerance and limit return to sport;3,4 or cognitive and psychological issues that impair return to learn or work.10
Many post-concussion symptoms can be attributed to brain injury, cervical spine injury, or both,3,4 and can have a long lasting negative impact on function, but can be modified through treatment of the relevant physiologic systems.3 Medical and athletic management of concussions has been delineated in a recent clinical practice guideline.10 In 2020, the American Physical Therapy Association published a clinical practice guideline describing current best practice for physical therapy care of concussion including cervical musculoskeletal, vestibulo-oculomotor, autonomic/exertional tolerance, motor function, and psychological and sociological impairments.11 Manual therapy may provide added value to the benefits of exercise in reducing cervicogenic headache and associated neck pain and dysfunction.12 For instance, treatments including cervical muscle active trigger point release and manipulative therapy can reduce intensity, frequency, and cervicogenic headache symptom duration.13 Visual system impairment can be reduced with vision therapy including oculomotor and vergence training using targets with numbers and letters, and fusion exercises such as stereograms and tranaglyphs.14 Vestibular therapy such as vestibulo-ocular reflex movements for adaptation, habituation exercises, and substitution including static and dynamic balance exercises can improve vestibulo-oculomotor symptoms after concussions.9,15 Although multisystem involvement is common, existing treatment protocols typically describe interventions focused on the symptom clusters arising from one system or another.9
Treatment outcomes for post-concussion syndrome can be complicated by the interconnectedness of the vestibular, visual, and musculoskeletal systems.16 For instance, vestibular therapy requires the ability to maintain visual fixation on a point while turning the head.9 Furthermore, deficits in cervical spine and oculomotor coordination can lead to dizziness and blurred vision.17 The function of the cervical spine, visual and vestibular systems are not isolated. Without the ability to have both eyes converge on a point or comfortably rotate the cervical spine, compensations can occur.9 While current clinical practice guidelines outline potential treatments to help address the symptoms that occur in each of the involved systems, no preferred treatment sequence for patients with post-concussion syndrome has emerged.10,11 The purpose of this study was to describe the clinical and patient-reported outcomes for people with post-concussion symptoms after a rehabilitation protocol sequenced to address cervical dysfunction and benign paroxysmal positional vertigo within the first three weeks of injury, followed by integrated vision and vestibular therapy.
Method
Design
This study was a retrospective longitudinal cohort analysis of pre-existing data obtained from August 2016 - March 2017 from a single concussion clinic. Deidentified coded data was received for analysis from the participating concussion clinic in accordance with the protocol approved by the Columbia University Irving Medical Center Institutional Review Board of the participating University Medical Center.
Sample
The records of 59 people with post-concussion symptoms were reviewed. The 38 patients (25 male and 13 female, aged 26.9±19.7 years) who had both evaluation and re-evaluation data—follow-up progress report or discharge assessment—were included for analysis. All patients had been referred for symptoms post-concussion and suspected mild traumatic brain injury with cervicogenic, visual, and/or vestibular symptoms. The average time from injury to initial evaluation was 31.6 ± 50.4 days, with 17 reporting protracted symptoms beyond 21 days. The most common presentation was mixed cervical, vision and vestibular symptoms reported by 24 (63.2%); followed by 10 (26.3%) that had vision and vestibular symptoms; and 4 (10.5%) that reported only cervicogenic symptoms including headache. Concussion etiology was varied with concussions occurring after sport (60.5%), fall (18.4%), motor vehicle accident (13.2%), and assaults (7.9%). A history of prior concussion was reported by 15 (39.5%). Table 1.
Table 1: Characteristics of the Patient Cohort.
| Sex | 25 males, 13 female |
| Age | 26.9 ± 19.7 years |
| History of Concussion | 39.5% |
|
Activity at Time of Injury Sport Fall Motor Vehicle Accident Assault |
60.5% 18.4% 13.2% 7.9% |
|
Symptoms Vision and Vestibular only Musculoskeletal (includes cervicogenic headache) only Vision and Vestibular with Musculoskeletal |
26.3% 10.5% 63.2% |
Assessments
Clinical findings and patient-reported outcomes were obtained by one trained clinician in the participating specialized concussion rehabilitation clinic. To minimize variation among different clinicians for patients who had limited cervical ROM at the initial evaluation, the cervical ROM measure was reduced for analysis in this study to a simple dichotomous outcome. ROM was either normal, denoted in the clinical notes as normal, within normal or within functional limits, or limited, defined as any limitation recorded in degrees, percentage, or qualitative term. Visual system outcome measures included the Brock string score for convergence and divergence distance,18 the cover-uncover test to screen for malalignment and strabismus that would require neuro-optometry referral,19 and clinical screening for quality and speed of smooth pursuits and saccades, and near point convergence.20 Vestibular measures included Dix-Hallpike and Supine Roll Tests for benign paroxysmal positional vertigo (BPPV). Additional vestibular screening assessments included vestibular ocular reflex, visual motion sensitivity and the Balance Error Scoring System (BESS), which has been shown to be a reliable measure in athletes post-concussion.21
Patient-reported outcomes included five scales that collectively provide insight on the potential symptoms that stem from deficits in the cervical spine, vestibular and visual systems.22–26 The Post-Concussion Symptom Scale (PCSS) assesses general post-concussion symptoms with specific symptom indices for associated sequelae including headache, with variable reliability for the different indices.22 The Dizziness Handicap Inventory (DHI) assesses the impact of dizziness on functional, emotional, and physical quality of life with excellent reliability and internal consistency.23 Visual impairment was assessed with the Convergence Insufficiency Symptom Survey (CISS), which has excellent reliability,24 and the Acquired Traumatic Brain Injury Vision Symptom Questionnaire, since adapted and renamed the Brain Injury Vision Symptom Survey (BIVSS).25 Finally, the Activities-specific Balance Confidence (ABC) scale assesses individual sense of balance and correlates with cognitive measures after concussion.26 See Table 2.
Table 2: Clinical and Patient-reported Outcomes.
| System | Assessments | Outcomes |
|---|---|---|
| Combined | Post-Concussion Symptom Scale | p=0.001, 95%CI 12.4 – 30.6, n=19, d=1.18 |
| Musculoskeletal | Cervical ROM | 55.6% (15/27) regained full ROM |
| Vision Convergence Saccades |
Convergence Insufficiency Scale Brain Injury Vision Symptom Survey Near-point Brock string score Saccade score |
p=0.002, 95%CI 7.1 – 18.3, n=19, d=1.04 p<0.001, 95%CI=13.4-28.0, n=15, d=1.21 p<0.001, 95%CI 3.3 – 6.3, n=23, d=1.20 p>0.05, n=13 |
| Vestibular BPPV Balance-objective Balance-subjective |
Dizziness Handicap Index BPPV symptoms Balance Error Scoring System Activity-specific Balance Confidence |
p<0.001, 95%CI 14.5 – 33.2, n=19, d=1.04 100% (28/28) resolved fully p<0.001, 95%CI 5.5 – 11.6, n=14, d=0.99 p=0.024, 95%CI -0.3 - -0.1, n=16, d=-0.89 |
BPPV = Benign Paroxysmal Positional Vertigo
ROM = Range of Motion
95%CI = 95% Confidence Interval
Interventions
Patients received treatment integrating cervical, vision and vestibular dysfunction as indicated by individual impairment and determined pragmatically by the trained concussion clinic treatment specialist, as previously outlined in a treatment algorithm.27 Patients evaluated within the three-week post-injury recovery window began treatment for cervical dysfunction and symptoms. Patients evaluated more than three weeks post-injury, consistent with protracted concussion recovery,3 began with treatment for cervical dysfunction integrated with vision and vestibular therapy. Because resolution of the multiple systems varied, treatments overlapped.
Cervical dysfunction was treated with manual therapy and exercise,12 followed by canalith repositioning procedure for BPPV when present.28 Vision therapy included vision exercises for smooth pursuits, saccades, complex motor tasks including divided attention and laterality, and vergences.29 Vestibular rehabilitation therapy was integrated for substitution (dynamic balance exercises with visual restriction and on compliant surfaces), vestibular ocular reflex training for gaze stability to address adaptation and exercises for habituation were added on or after the 3rd week of vision therapy.27 The principles of substitution, adaptation, and habituation were applied to improve balance, postural control, dizziness, oscillopsia, and complaints of motion intolerance.30 In addition, independent daily light cardiovascular activity for 20 minutes, consistent with the Buffalo Treadmill Test,3 was recommended for all patients who were greater than three days post-injury.
Statistical Methods
All statistics were run in Stata for Mac. Descriptive data were calculated including means and standard deviations, with counts presented with percentages. Non-parametric and parametric statistics were used as appropriate after assessment of normal distribution patterns. Effect sizes were calculated with values of Cohen’s d considered large if ≥0.8, medium if 0.5≤ d <0.8, and small if 0.2≤ d < 0.5. Paired t-tests were run using Bonferroni correction to control for familywise error and guard against false positives due to multiple comparisons (p<0.05).
Results
The 38 patients with follow-up data received an average of 10.4±4.8 treatment sessions over 57.6±34.0 days. The average number of sessions addressing cervical dysfunction was 4.0±3.8, vision and vestibular dysfunction 4.8±3.0, and combined symptoms 1.7±0.8.
Significant improvements were observed at post-test for general post-concussion symptoms on the patient-reported PCSS (p=0.001, d=1.18). See Table 2. Musculoskeletal, visual, and vestibular symptom outcome measures improved as indicated on clinical measures and patient reported outcomes. Cervical ROM returned to normal for 15 of the 27 people who had limitations on evaluation (55.6%). Vision function significantly improved for convergence on Brock string score (p<0.001, d=1.20). Subjective vision symptoms assessed with the CISS also improved significantly (p<0.002, d=1.04). Divergence and abnormal saccades did not change significantly (p>0.05). Symptoms of BPPV were fully resolved for all 28/28 (100%) diagnosed with BPPV. Vestibular system impairment represented by clinical measure of balance ability using the BESS improved significantly (p<0.001, d=0.99). The subjective patient-reported outcome ABC scale also improved significantly post treatment (p<0.024, d=-0.89). Vestibulo-oculomotor symptoms improved significantly post-treatment, assessed with the DHI (p<0.001, d=1.04) and BIVSS (p<0.001, d=1.21). See Table 2.
Discussion
The results of this retrospective cohort study showed that patients receiving physical therapy, consisting of manual therapy and exercise for cervical dysfunction and BPPV in the first three weeks post-concussion followed by vision and vestibular rehabilitation therapy beyond three weeks post injury, demonstrated clinical and patient-reported benefits in multiple systems. Improved cervical dysfunction such as limited ROM and headache following head injury, as well as other causes of post-concussion symptoms, can be contributed to by concomitant whiplash injury suffered at the time of the concussion.16 Changes in neck muscle activity during cervical rotation and cervico-ocular coordination may underlie clinical symptoms reported by people with visual deficits and changes in function, such as postural control, during cervical rotation.17 Regardless, whether cervicogenic headaches include pain, dizziness, and/or oculomotor dysfunction,8 restoring cervical ROM may well be one factor affecting multiple systems.31 Findings in the current study for the musculoskeletal, vision, and vestibular systems were consistent with past literature for select recommendation of the most recent clinical practice guidelines.10,11
Reducing musculoskeletal limitation was an important early goal because of the importance of cervical ROM for vision and vestibular assessments and rehabilitation and the impact cervical dysfunction has on headaches, visual and vestibular function. Most subjects regained full cervical ROM by re-evaluation, though data for some patients was missing, the measurement method was unreported, and the definition for full ROM can vary.7 Direct comparison of the study results with past reports that have shown that manual therapies improve cervical ROM with thrust or mobilization with movement31,32 was not possible because the retrospective data did not include specific manual techniques. Evidence for the efficacy of using manual therapy to reduce cervicogenic headache remains limited by the number of studies and lack of no-treatment control groups.8 One randomized controlled trial demonstrated increased ROM after sustained natural apophyseal glides but no significant improvement in dizziness or balance for people with chronic cervicogenic dizziness.31 Cervicogenic headache was not analyzed directly in this study, though headache was an item included in the total PCSS scores which improved significantly at re-evaluation. Starting care by addressing cervical dysfunction within the first three-weeks post-injury when indicated may be one among many factors in the improvements seen for cervical dysfunction as well as vision and vestibular outcome measures.
One common vision system dysfunction, convergence insufficiency, has been associated with other neurocognitive impairments and higher PCSS.33 After the study treatment, patient-reported symptoms on the PCSS had improved significantly as did clinical Brock string measures for near point convergence consistent with a five subject pilot study34 and a case-control study including 15 people with mild traumatic brain injury.35 Randomized controlled trials would be the next step to determine effect of vision therapy post-concussion compared to no treatment. Clinical measure of abnormal saccades did not change for patients post-treatment, consistent with past research.35 Missing data precluded analysis of other visual deficits common after minor traumatic brain injury such as smooth pursuits, and eye alignment.16 Also consistent with previous findings, patient-reported outcomes for vision symptoms improved significantly on the CISS and BIVSS.25,34,36 The oculomotor and vestibular systems are highly interconnected with integrated roles in maintaining balance, postural control and gaze stabilization,16 and patients exhibited benefits in both systems.
Evidence supports vestibular system rehabilitation for both central and peripheral deficits in concussion management.37 Physical therapy for cervical dysfunction has improved both musculoskeletal and vestibular symptoms including dizziness attributed to BPPV.37 In the current study, treatment for cervical dysfunction followed by canalith reposition procedures for BPPV was provided when indicated within the 3-week post injury timeframe instead of waiting for the 3-week post injury period when vision and vestibular rehabilitation began. Addressing BPPV before other vestibular deficits was similar to one past study, that aimed to reduce the confounding effect of BPPV on balance outcomes by treating BPPV first before introducing any habituation approaches.38 That all patients with BPPV had complete symptom resolution after treatment was comparable to past outcomes for the Epley maneuver summarized in a recent systematic review.39 Patient-reported outcome measures including the ABC scale and DHI both improved, consistent with a past retrospective cohort study of vestibular rehabilitation post-concussion.30
The recent clinical practice guidelines for mild traumatic brain injury supports multi-modal rehabilitation10,11 and physical therapy models of care for protracted concussion recovery have included cervical dysfunction and vestibular-ocular care and exertional activity without specific intervention sequence.40 The results of this study suggest that the intervention sequence27 addressing cervical dysfunction and BPPV within the three weeks post-injury before initiating vision and vestibular rehabilitation at more than three weeks post-injury may yield positive outcomes. Early cervical ROM restoration is important because cervical motion can have a confounding impact of cervicogenic headaches, and vision and vestibular function; while BPPV symptoms can confound both vestibular-ocular and vestibular spinal function including balance assessments.38 Since post-concussion symptoms resolve spontaneously for 80-90% of adults within 2 weeks, delaying therapeutic vision and vestibular training in the early period of recovery can avoid unnecessary symptom exacerbation.3 Within an overall integrated treatment approach, sequencing cervical dysfunction and BPPV treatment before advancing to vision and vestibular rehabilitation acknowledges the role cervical ROM plays in both vision and vestibular function16,17,33,40 and may improve the ability to perform functional activities early in the episode of care. Developing exercise tolerance thereafter would precede a return to sport.40 In total, the inter-relationships among the musculoskeletal, vision and vestibular systems, with respect to both function and treatment, make screening for and addressing cervical dysfunction a logical first step even before the three-week post-injury timeframe for starting vision and vestibular rehabilitation.
Limitations of this retrospective cohort analysis of deidentified preexisting data included the lack of a control group and inability to obtain follow-up or missing data. Specific sport involvement was not consistently recorded, although at least 10 concussions were due to skiing; and return to sport outcomes were not available. Headache pain, which was incorporated in the PCSS, was also not individually assessed. The small sample size limited ability to analyze sub-groups or perform regression analysis of factors associated with the outcomes. Patients with missing re-evaluation data could not be included in the pre-post analysis, thus although effect size changes were large, results should be viewed with caution given unknown outcomes in at least 35.6%. The potential exists for selection bias due to recruitment from a single concussion clinic. However, participation of the one concussion clinic allowed consistent use of the established protocol that sequenced and integrated musculoskeletal, vision and vestibular system care. Finally, the pragmatic treatment approach meant that variation in specific patient treatments was not controlled for, though results suggest that direct comparison of the study approach with a no-treatment control or alternate treatment condition would be warranted.
Conclusion
After concussion, symptoms can arise from multiple systems with musculoskeletal, visual, and vestibular dysfunction. Because cervical ROM is a part of both the assessment and treatment of visual and vestibular dysfunction, cervical limitations can confound symptoms in both systems. The results of this study showed that patients with post-concussion symptoms receiving treatment sequenced to address cervical ROM limitations and BPPV symptoms in the first three weeks, integrated into visual and vestibular rehabilitation improved clinical and patient-reported outcomes for all systems. The interconnectedness of the systems makes sequencing care to address musculoskeletal function before the 3-week post-concussion recovery window in a clinical approach that then integrates vision and vestibular system function a promising approach for concussion recovery.
Conflicts of Interest
The authors have no conflicts to disclose.
Disclosures
This study received no funding.
References
- The epidemiology and impact of traumatic brain injury. Langlois Jean A., Rutland-Brown Wesley, Wald Marlena M. Sep;2006 Journal of Head Trauma Rehabilitation. 21(5):375–378. doi: 10.1097/00001199-200609000-00001. doi: 10.1097/00001199-200609000-00001. [DOI] [PubMed] [Google Scholar]
- Concussion (mild traumatic brain injury) and the team physician: A consensus statement-2011 update. Herring S. A., Cantu R. C., Guskiewicz K. M.., et al. Dec;2011 Medicine & Science in Sports & Exercise. 43(12):2412–2422. doi: 10.1249/mss.0b013e3182342e64. doi: 10.1249/mss.0b013e3182342e64. [DOI] [PubMed] [Google Scholar]
- Active rehabilitation of concussion and post-concussion syndrome. Leddy John J., Baker John G., Willer Barry. May;2016 Physical Medicine and Rehabilitation Clinics of North America. 27(2):437–454. doi: 10.1016/j.pmr.2015.12.003. doi: 10.1016/j.pmr.2015.12.003. [DOI] [PubMed] [Google Scholar]
- Rest and treatment/rehabilitation following sport-related concussion: A systematic review. Schneider Kathryn J., Leddy John J., Guskiewicz Kevin M., Seifert Tad, McCrea Michael, Silverberg Noah D., Feddermann-Demont Nina, Iverson Grant L., Hayden Alix, Makdissi Michael. Mar 24;2017 British Journal of Sports Medicine. 51(12):930–934. doi: 10.1136/bjsports-2016-097475. doi: 10.1136/bjsports-2016-097475. [DOI] [PubMed] [Google Scholar]
- Kostyun Regina O., Hafeez Imran. Sports Health: A Multidisciplinary Approach. 1. Vol. 7. SAGE Publications; Protracted recovery from a concussion: A focus on gender and treatment interventions in an adolescent population; pp. 52–57. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Concussion: Purely a brain injury? Leslie Oliver, Craton Neil. Sep;2013 Clinical Journal of Sport Medicine. 23(5):331–332. doi: 10.1097/jsm.0b013e318295bbb1. doi: 10.1097/jsm.0b013e318295bbb1. [DOI] [PubMed] [Google Scholar]
- Tiwari Devashish, Goldberg Allon, Yorke Amy, Marchetti Gregory F., Alsalaheen Bara. International Journal of Sports Physical Therapy. 2. Vol. 14. The Sports Physical Therapy Session; Characterization of cervical spine impairments in children and adolescents post-concussion; pp. 282–295. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chaibi Aleksander, Russell Michael Bjørn. The Journal of Headache and Pain. 5. Vol. 13. Springer Science and Business Media LLC; Manual therapies for cervicogenic headache: A systematic review; pp. 351–359. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vestibular rehabilitation is associated with visuovestibular improvement in pediatric concussion. Storey Eileen P., Wiebe Douglas J., DʼAlonzo Bernadette A., Nixon-Cave Kim, Jackson-Coty Janet, Goodman Arlene M., Grady Matthew F., Master Christina L. Jul;2018 Journal of Neurologic Physical Therapy. 42(3):134–141. doi: 10.1097/npt.0000000000000228. doi: 10.1097/npt.0000000000000228. [DOI] [PubMed] [Google Scholar]
- Updated clinical practice guidelines for concussion/mild traumatic brain injury and persistent symptoms. Marshall Shawn, Bayley Mark, McCullagh Scott, Velikonja Diana, Berrigan Lindsay, Ouchterlony Donna, Weegar Kelly. Apr 14;2015 Brain Injury. 29(6):688–700. doi: 10.3109/02699052.2015.1004755. doi: 10.3109/02699052.2015.1004755. [DOI] [PubMed] [Google Scholar]
- Physical therapy evaluation and treatment after concussion/mild traumatic brain injury. Quatman-Yates C.C., Hunter-Giordano A., Shimamura K.K.., et al. 2020J Orthop Sports Phys Ther. 50(4):CPG1–CPG73. doi: 10.2519/jospt.2020.0301. [DOI] [PubMed] [Google Scholar]
- Varatharajan Sharanya, Ferguson Brad, Chrobak Karen, Shergill Yaadwinder, Côté Pierre, Wong Jessica J., Yu Hainan, Shearer Heather M., Southerst Danielle, Sutton Deborah, Randhawa Kristi, Jacobs Craig, Abdulla Sean, Woitzik Erin, Marchand Andrée-Anne, van der Velde Gabrielle, Carroll Linda J., Nordin Margareta, Ammendolia Carlo, Mior Silvano, Ameis Arthur, Stupar Maja, Taylor-Vaisey Anne. European Spine Journal. 7. Vol. 25. Springer Science and Business Media LLC; Are non-invasive interventions effective for the management of headaches associated with neck pain? An update of the Bone and Joint Decade Task Force on Neck Pain and Its Associated Disorders by the Ontario Protocol for Traffic Injury Management (OPTIMa) Collaboration; pp. 1971–1999. [DOI] [PubMed] [Google Scholar]
- Efficacy of interventions used by physiotherapists for patients with headache and migraine—systematic review and meta-analysis. Luedtke Kerstin, Allers Angie, Schulte Laura H, May Arne. Jul 30;2015 Cephalalgia. 36(5):474–492. doi: 10.1177/0333102415597889. doi: 10.1177/0333102415597889. [DOI] [PubMed] [Google Scholar]
- Thiagarajan Preethi, Ciuffreda Kenneth J. Journal of Rehabilitation Research and Development. 9. Vol. 50. Journal of Rehabilitation Research & Development; Effect of oculomotor rehabilitation on vergence responsivity in mild traumatic brain injury; pp. 1223–1240. [DOI] [PubMed] [Google Scholar]
- Alsalaheen Bara A., Whitney Susan L., Mucha Anne, Morris Laura O., Furman Joseph M., Sparto Patrick J. Physiotherapy Research International. 2. Vol. 18. Wiley; Exercise prescription patterns in patients treated with vestibular rehabilitation after concussion; pp. 100–108. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Treleaven Julia. Journal of Orthopaedic & Sports Physical Therapy. 7. Vol. 47. Journal of Orthopaedic & Sports Physical Therapy (JOSPT); Dizziness, unsteadiness, visual disturbances, and sensorimotor control in traumatic neck pain; pp. 492–502. [DOI] [PubMed] [Google Scholar]
- Bexander Catharina S. M., Hodges Paul W. Experimental Brain Research. 1. Vol. 217. Springer Science and Business Media LLC; Cervico-ocular coordination during neck rotation is distorted in people with whiplash-associated disorders; pp. 67–77. [DOI] [PubMed] [Google Scholar]
- The relationship between phoria and the ratio of convergence peak velocity to divergence peak velocity. Kim Eun H., Granger-Donetti Bérangère, Vicci Vincent R., Alvarez Tara L. Aug 1;2010 Investigative Opthalmology & Visual Science. 51(8):4017–4027. doi: 10.1167/iovs.09-4560. doi: 10.1167/iovs.09-4560. [DOI] [PubMed] [Google Scholar]
- Mestre Clara, Otero Carles, Díaz-Doutón Fernando, Gautier Josselin, Pujol Jaume. An automated and objective cover test to measure heterophoria. In: Maiello Guido., editor. PLOS ONE. 11. Vol. 13. Public Library of Science (PLoS); p. e0206674. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Heick John D., Bay Curt, Valovich McLeod Tamara C. International Journal of Sports Physical Therapy. 5. Vol. 13. The Sports Physical Therapy Session; Evaluation of vertical and horizontal saccades using the developmental eye movement test compared to the King-Devick test; pp. 808–818. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Reliability and validity evidence of multiple balance assessments in athletes with a concussion. Murray Nicholas, Salvatore Anthony, Powell Douglas, Reed-Jones Rebecca. Aug 1;2014 Journal of Athletic Training. 49(4):540–549. doi: 10.4085/1062-6050-49.3.32. doi: 10.4085/1062-6050-49.3.32. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Evaluating the test-retest reliability of symptom indices associated with the ImPACT post-concussion symptom scale (PCSS) Merritt Victoria C., Bradson Megan L., Meyer Jessica E., Arnett Peter A. May;2018 Journal of Clinical and Experimental Neuropsychology. 40(4):377–388. doi: 10.1080/13803395.2017.1353590. doi: 10.1080/13803395.2017.1353590. [DOI] [PubMed] [Google Scholar]
- Dizziness Handicap Inventory (DHI) Treleaven Julia. 2006Australian Journal of Physiotherapy. 52(1):67. doi: 10.1016/s0004-9514(06)70070-8. doi: 10.1016/s0004-9514(06)70070-8. [DOI] [PubMed] [Google Scholar]
- Validity of the convergence insufficiency symptom survey: a confirmatory study. Rouse Michael, Borsting Eric, Mitchell G Lynn, Cotter Susan A., Kulp Marjean, Scheiman Mitchell, Barnhardt Carmen, Bade Annette, Yamada Tomohike. Apr;2009 Optometry and Vision Science. 86(4):357–363. doi: 10.1097/opx.0b013e3181989252. doi: 10.1097/opx.0b013e3181989252. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brain Injury Vision Symptom Survey (BIVSS) Questionnaire. Laukkanen Hannu, Scheiman Mitchell, Hayes John R. Jan;2017 Optometry and Vision Science. 94(1):43–50. doi: 10.1097/opx.0000000000000940. doi: 10.1097/opx.0000000000000940. [DOI] [PubMed] [Google Scholar]
- Relationship between cognitive assessment and balance measures in adolescents referred for vestibular physical therapy after concussion. Alsalaheen Bara A., Whitney Susan L., Marchetti Gregory F., Furman Joseph M., Kontos Anthony P., Collins Michael W., Sparto Patrick J. Jan;2016 Clinical Journal of Sport Medicine. 26(1):46–52. doi: 10.1097/jsm.0000000000000185. doi: 10.1097/jsm.0000000000000185. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Integration of vision and vestibular therapy for vestibulo-ocular post-concussion disorder: A case study. Ziaks L., Giardina R., Kloos A. 2019Int J Allied Health Sci Pract. 17(3):Article 11. [Google Scholar]
- Benign positional vertigo, its diagnosis, treatment and mimics. Argaet E.C., Bradshaw A.P., Welgampola M.S. 2019Clinical Neurophysiology Practice. 4:97–111. doi: 10.1016/j.cnp.2019.03.001. doi: 10.1016/j.cnp.2019.03.001. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Scheiman M. Understanding and Managing Vision Deficits: A Guide for Occupational Therapists. Slack Inc; Thorofare, NJ: [Google Scholar]
- Vestibular rehabilitation for dizziness and balance disorders after concussion. Alsalaheen Bara A., Mucha Anne, Morris Laura O., Whitney Susan L., Furman Joseph M., Camiolo-Reddy Cara E., Collins Michael W., Lovell Mark R., Sparto Patrick J. Jun;2010 Journal of Neurologic Physical Therapy. 34(2):87–93. doi: 10.1097/npt.0b013e3181dde568. doi: 10.1097/npt.0b013e3181dde568. [DOI] [PubMed] [Google Scholar]
- Effects of cervical spine manual therapy on range of motion, head repositioning, and balance in participants with cervicogenic dizziness: a randomized controlled trial. Reid Susan A., Callister Robin, Katekar Michael G., Rivett Darren A. Sep;2014 Archives of Physical Medicine and Rehabilitation. 95(9):1603–1612. doi: 10.1016/j.apmr.2014.04.009. doi: 10.1016/j.apmr.2014.04.009. [DOI] [PubMed] [Google Scholar]
- Dunning James R., Cleland Joshua A., Waldrop Mark A., Arnot Cathy, Young Ian, Turner Michael, Sigurdsson Gisli. Journal of Orthopaedic & Sports Physical Therapy. 1. Vol. 42. Journal of Orthopaedic & Sports Physical Therapy (JOSPT); Upper cervical and upper thoracic thrust manipulation versus nonthrust mobilization in patients with mechanical neck pain: A multicenter randomized clinical trial; pp. 5–18. [DOI] [PubMed] [Google Scholar]
- Pearce Kelly L., Sufrinko Alicia, Lau Brian C., Henry Luke, Collins Michael W., Kontos Anthony P. The American Journal of Sports Medicine. 12. Vol. 43. SAGE Publications; Near point of convergence after a sport-related concussion: Measurement reliability and relationship to neurocognitive impairment and symptoms; pp. 3055–3061. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Objective assessment of vergence after treatment of concussion-related CI: A pilot study. Scheiman Mitchell M., Talasan Henry, Mitchell G. Lynn, Alvarez Tara L. Jan;2017 Optometry and Vision Science. 94(1):74–88. doi: 10.1097/opx.0000000000000936. doi: 10.1097/opx.0000000000000936. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Matuseviciene Giedre, Johansson Jan, Möller Marika, Godbolt Alison K., Pansell Tony, Deboussard Catharina Nygren. BMJ Open. 2. Vol. 8. BMJ; Longitudinal changes in oculomotor function in young adults with mild traumatic brain injury in Sweden: An exploratory prospective observational study; p. e018734. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Preliminary evidence for improvement in symptoms, cognitive, vestibular, and oculomotor outcomes following targeted intervention with chronic mTBI patients. Kontos Anthony P, Collins Michael W, Holland Cyndi L, Reeves Valerie L, Edelman Kathryn, Benso Steven, Schneider Walter, Okonkwo David. Mar 1;2018 Military Medicine. 183(suppl_1):333–338. doi: 10.1093/milmed/usx172. doi: 10.1093/milmed/usx172. [DOI] [PubMed] [Google Scholar]
- Schneider Kathryn J, Meeuwisse Willem H, Nettel-Aguirre Alberto, Barlow Karen, Boyd Lara, Kang Jian, Emery Carolyn A. British Journal of Sports Medicine. 17. Vol. 48. BMJ; Cervicovestibular rehabilitation in sport-related concussion: A randomised controlled trial; pp. 1294–1298. [DOI] [PubMed] [Google Scholar]
- Vestibular rehabilitation following mild traumatic brain injury. Gurley James M., Hujsak Bryan D., Kelly Jennifer L. May 21;2013 NeuroRehabilitation. 32(3):519–528. doi: 10.3233/NRE-130874. doi: 10.3233/NRE-130874. [DOI] [PubMed] [Google Scholar]
- The Epley (canalith repositioning) manoeuvre for benign paroxysmal positional vertigo. Hilton Malcolm P, Pinder Darren K. Dec 8;2014 Cochrane Database of Systematic Reviews. (12):Art. No.: CD003162. doi: 10.1002/14651858.cd003162.pub3. doi: 10.1002/14651858.cd003162.pub3. [DOI] [PMC free article] [PubMed]
- A conceptual model for physical therapists treating athletes with protracted recovery following a concussion. Lundblad M. 2017Int J Sports Phys Ther. 12(2):286–296. [PMC free article] [PubMed] [Google Scholar]
