VESTIBULAR TESTING IN CHILDREN WITH DIZZINESS AND BALANCE CONCERNS AFTER CONCUSSION: LABORATORY AND CLINICAL RESULTS

BACKGROUND: Dizziness is the second most common symptom in people who sustain a concussion and there are few reports on vestibular laboratory findings in the concussed pediatric population. Studies to date have shown conflicting findings regarding incidence of peripheral vestibular disorders. Hypothesis/Purpose: The purpose of this study is to report vestibular laboratory and clinical examination findings in concussed youth referred to a multidisciplinary vestibular clinic. METHODS: A retrospective chart review was performed for all patients (n=474) seen from August 2017 to March 2020 for a single comprehensive examination in a multidisciplinary pediatric vestibular specialty clinic. Data was extracted from the charts of patients (n=64) with a history of concussion referred because of chronic dizziness and/or imbalance. Each patient was examined by a neurotologist, physical therapist, and audiologist with specialized training in vestibular disorders. Vestibular laboratory testing performed by audiologists included video nystagmography (VNG) evaluation of oculomotor function and BPPV, rotational chair, video head impulse test (vHIT), vestibular evoked myogenic potentials (VEMPs), post-headshake nystagmus, and caloric irrigation. Physical therapy clinical examination included dynamic visual acuity testing (DVA), vestibular/oculomotor screening (VOMS), and sensory organization test (SOT). Not all tests were performed on every patient secondary to factors such as insurance coverage, patient tolerance, and young age. RESULTS: 1 or more components of VOMS was abnormal in 30 of 53 patients examined. DVA was completed on 40 patients, 23 of which were reported as abnormal. SOT was completed on 46 patients, 18 of which demonstrated below normal composite equilibrium scores. Laboratory findings were as follows: VEMPs (n=50) were normal in all but 1 patient, vHIT (n=59), caloric irrigation (n=26), post-headshake nystagmus (n=49), and positional testing (n=55) were normal on all patients tested. Rotational chair (n=60) was performed at 4 different frequencies and revealed low gain in 3 patients. CONCLUSION: Vestibular laboratory examination was normal in nearly all subjects tested. These results suggest that in concussed youth with chronic dizziness and/or imbalance, laboratory vestibular test outcomes indicative of peripheral dysfunction are rare, which contradicts previous research in this population. In contrast, clinical vestibular assessment was abnormal in more than 50% of subjects examined which suggests that clinicians should use caution interpreting clinical examination findings for diagnosing peripheral vestibular dysfunction. Abnormal clinical examination findings may be indicative of central vestibular conditions such as space and motion intolerance and PPPD in chronically dizzy pediatric patients after concussion. TABLES/FIGURES: