The Gaze Stabilization Test Following Concussion.

BACKGROUND: Concussion can cause vestibular dysfunction and oculomotor abnormalities which can lead to dizziness and protracted recovery time. There are few clinically useful, functional measures of the vestibulo-ocular reflex (VOR) post-concussion.

PURPOSE: The purpose of this study was to examine the gaze stabilization test (GST) in those referred for vestibular physical therapy following concussion, to determine the association between GST and other measures of recovery following concussion, and to examine the effect of demographic variables on GST performance.

RESEARCH DESIGN: Retrospective chart review.

STUDY SAMPLE: One hundred fifty-eight individuals who sustained a concussion and were referred to vestibular physical therapy.

DATA COLLECTION AND ANALYSIS: Horizontal and vertical GST scores (HGST and VGST), neurocognitive testing results, and demographic data were extracted retrospectively from the patient health record. Correlations between GST velocity and neurocognitive test results and between GST and patient-reported outcomes were examined. Differences in GST performance among patient subgroups were examined using one-way analysis of variance.

RESULTS: Subjects included individuals aged 12 to 43 years (mean = 20, standard deviation [SD] = 7), with most having sport-related concussion (67%). The mean time from injury to GST was 215 days (SD = 241) and the mean time from physical therapy evaluation to GST was 48 days (SD = 54). HGST and VGST had a weak positive correlation to the Activities-Specific Balance Confidence Scale (r = 0.20, r = 0.21) and weak negative correlation to the Dizziness Handicap Inventory (r = -0.18, r = -0.22). HGST had a weak positive correlation to the visual motor processing speed domain of the immediate post-concussion assessment and cognitive test (r = 0.20). Male patients achieved significantly higher velocities than female patients on HGST and VGST (p = 0.02, p = 0.01).

CONCLUSIONS: The present study details the use of GST in patients with concussion and demonstrates an association with common outcome measures in vestibular rehabilitation. Results indicate that patients who achieved higher velocities on GST perceived lower handicap due to dizziness and had higher confidence in their balance. GST may be a relevant test of VOR in this population, as it is a more functional test of the VOR required for sports. Future work is needed to further evaluate the role of GST in concussion management.