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I. Gagnon1,2, C. Triantafillou3, A. Crampton1, E. Teel2, K. Schneider4,5,6, M. Katz-Leurer7, M. Chevignard8,9, M. Beauchamp10,11, C. Debert12
1McGill University, School of Physical and Occupational Therapy, Montreal, Canada, 2Montreal Children’s Hospital, McGill University Health Centre, Montreal, Canada, 3McGill University, Department of Psychology, Montreal, Canada, 4Sport Injury Prevention Research Centre, University of Calgary, Faculty of Kinesiology, Calgary, Canada, 5Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, Canada, 6Hotchkiss Brain Institute, University of Calgary, Calgary, Canada, 7University of Tel-Aviv, Physical Therapy Department, Tel-Aviv, Israel, 8Saint Maurice Hospitals, Rehabilitation Department for Children with Acquired Neurological Injury and Outreach Team for Children and Adolescents with Acquired Brain Injury, Saint Maurice, France, 9Sorbonne Université, Laboratoire d’Imagerie Biomédicale, Paris, France, 10ABC’s Laboratory, Ste-Justine Hospital Research Center, Montreal, Canada, 11University of Montreal, Department of Psychology, Montreal, Canada, 12University of Calgary, Department of Clinical Neurosciences, Calgary, Canada
Background: Ocular motor (OM) and vestibulo-ocular (VO) impairments are frequently reported in adult mTBI populations. Clinical outcome measures of OM and VO function are important as they allow one to quickly identify OM and VO deficits which maybe linked to difficulties with school and overall quality of life. Few studies are available that clearly document the prevalence of these findings in children and adolescents.
Purpose: To determine the proportion of children and adolescents that present with findings on clinical tests of OM and VO function, when compared to healthy uninjured children, within 21 days of sustaining a mTBI.
Methods: A total of 125 children and adolescents (median age: 14.3 (IQR: 12.9-15.9) years old, 63 males, 97 with mTBI) were assessed in this cross-sectional study. All participants were administered the Vestibular/Ocular Motor Screening (VOMS) assessment, the Head Thrust Test (HTT) and the clinical Dynamic Visual Acuity (DVA) Test in a tertiary care pediatric hospital.
Outcome measures: As per VOMS procedure, symptom scores (headache, dizziness, nausea, and fogginess) were recorded before and immediately following each of the VOMS tasks: smooth pursuit, saccades (horizontal, vertical), near point convergence, VOR (horizontal, vertical), and visual motion sensitivity (VMS). In addition, symptom provocation for a task assessing optokinetic nystagmus (OKN) was added. A total symptom increase of ≥2 points was considered abnormal for any of these tasks. The HTT uses short, unpredictable high-velocity head rotations to measure VOR function through clinician observation. Finally, the clinical DVA test compares static visual acuity (SVA) and DVA to provide information related to behavioral VOR. This test was abnormal if logMAR change from SVA to DVA was ≥ 0.2.
Analysis: Chi-square or Fisher’s exact tests compared the proportions of children with impairments of OM and VO functioning in concussed vs. control participants.
Outcome measures: As per VOMS procedure, symptom scores (headache, dizziness, nausea, and fogginess) were recorded before and immediately following each of the VOMS tasks: smooth pursuit, saccades (horizontal, vertical), near point convergence, VOR (horizontal, vertical), and visual motion sensitivity (VMS). In addition, symptom provocation for a task assessing optokinetic nystagmus (OKN) was added. A total symptom increase of ≥2 points was considered abnormal for any of these tasks. The HTT uses short, unpredictable high-velocity head rotations to measure VOR function through clinician observation. Finally, the clinical DVA test compares static visual acuity (SVA) and DVA to provide information related to behavioral VOR. This test was abnormal if logMAR change from SVA to DVA was ≥ 0.2.
Analysis: Chi-square or Fisher’s exact tests compared the proportions of children with impairments of OM and VO functioning in concussed vs. control participants.
Results: Participants with mTBI were significantly more likely to have increased symptoms on the VOMS: horizontal saccades (P= 0.0382), vertical saccades (P= 0.0120), convergence (P= 0.0068), horizontal VOR (χ2(1) = 9.94, P= 0.0016), vertical VOR (χ2(1) = 10.42, P= 0.0012), VMS (χ2(1) = 10.42, P= 0.0012) and OKN testing (P= 0.0066). No significant group differences were observed for the VOMS smooth pursuit, clinical DVA test, or HTT (P>0.05).
Conclusion(s): When considering symptom provocation during OM and VO tasks, children with mTBI have significantly more symptoms in every VOMS domain except smooth pursuits. No differences in performance on the HTT or clinical DVA were observed. Further studies should explore these findings with a larger sample size in children with mTBI to achieve a better understanding of OM and VO function following mTBI.
Implications: Future research could further explore early, targeted rehabilitation approaches, specific to children and adolescents with mTBI, to ensure healthy OM and VO functioning that best support their activities of daily life.
Funding, acknowledgements: Study was funded by FRQS and CIHR in the context of an EraNET Neuron initiative.
Keywords: concussion, ocular motor, vestibular
Topic: Paediatrics
Did this work require ethics approval? Yes
Institution: McGill University Health Centre (MUHC)
Committee: MUHC REB
Ethics number: MP-37-2018-3373
All authors, affiliations and abstracts have been published as submitted.
