Dizziness, Balance, and Related Symptoms following Mild Traumatic Brain Injury/Concussion in New Zealand: A Preliminary Study

Abstract

OBJECTIVE: This preliminary study sought to characterise dizziness and balance symptoms experienced after mild Traumatic Brain Injuries (mTBI), their relative prevalence, and onset. Other related features including vision, hearing, cognition, psychological distress, headaches/migraines, and number of concussions were also studied in their relationship to dizziness and balance. METHODS: Twenty-eight dizzy participants with mTBI were recruited in this questionnaire-based study. They answered questions relating to their concussion, types of dizziness, visual and hearing symptoms, and headaches or migraines. Auditory processing and cognitive disabilities were rated on scales. They also answered validated sub-questionnaires, including Dizziness Handicap Inventory (DHI), Hospital Anxiety and Depression Scale (HADS), Visual Vertigo Analogue Scale (VVA). One participant opted for vestibular testing. Two participants completed the follow-up questionnaire 6-7 months from injury to monitor changes. Descriptive statistics were used to characterise dizziness/balance symptoms and visual symptoms. The relationship between the DHI and other postconcussion symptoms was explored using Spearman’s Correlation, Mann Whitney U and Fisher’s Exact tests. RESULTS: Most mTBI individuals complained of more than one specific dizziness symptom. The most common being unsteadiness, followed by “a spinning sensation with triggers.” Dizziness symptoms usually developed within the first week following the injury, although delays of up to six months were reported. Most patients (75%) reported an improvement in their dizzy symptoms over time. There were moderate to strong positive correlations between dizziness handicap (DHI), visual vertigo (VVA), auditory processing difficulties, and cognitive difficulties (p < 0.005). Presence of headaches/migraines after the injury was associated with significantly higher visual vertigo than those without headaches/migraines. CONCLUSIONS: Different mechanisms causing dizziness after mTBI could occur in parallel or subsequence. mTBI individuals with increased disability from dizziness also reported increased auditory processing difficulties, increased visual vertigo, and increased cognitive difficulties. This supports the idea that sensory impairment after mTBI is a multimodal process. Further work in groups of other sensory disabilities can complement existing results. SIGNIFICANCE: This was the first study to explore the relationship between dizziness and auditory processing. The positive association between these two domains further supports the notion that deficits after mTBI are a global process.