(834) Does head trauma explain vestibular abnormalities in adults with substance use disorders?

Introduction: Adults with substance use disorders (SUD) have a high occurrence of head trauma and are at risk for vestibular abnormalities related to substances. However, because vestibular symptoms are similar between head trauma and substance misuse, the relative contribution of head trauma versus SUDs to vestibular outcomes is unclear.

Methods: Data were analyzed from a multisite cohort of adults with SUD (n=179) and controls (n=102) who completed a health questionnaire and underwent vestibular assessment from 2023-2025. Outcomes included report of dizziness/imbalance and vestibular abnormality seen on bedside exam, videonystagmography, video Head Impulse Test, vestibular evoked myogenic potentials, or balance. Analyses used logistic regression adjusted for site to estimate adjusted odds ratios (aOR) with confidence intervals (CI) and p-values.

Results: Head trauma was more common in SUD (38/177, 21.5%) than controls (9/102, 8.8%; aOR 2.91, 95% CI 1.33–6.38; p=0.008). Vestibular symptoms were higher in SUD (52/176, 29.5%) than controls (11/102, 10.8%; aOR 3.76, 95% CI 1.84–7.71; p< 0.001). Vestibular abnormality occurred in 164/174 (94.3%) of SUD versus 63/102 (61.8%) of controls (aOR 10.74, 95% CI 4.94–23.35; p< 0.001). Among SUD without head trauma, 130/137 (94.9%) still demonstrated ≥1 vestibular abnormality. Within SUD, head trauma predicted vestibular symptoms (aOR 2.39, 95% CI 1.13–5.05; p=0.023) but not vestibular abnormality (aOR 0.60, 95% CI 0.15–2.47; p=0.48).

Conclusions: Adults with SUD exhibit higher vestibular symptom burden and abnormalities than controls. Although head trauma is more prevalent in SUDs, it does not fully account for high incidence of vestibular abnormalities in people with SUDs, supporting routine vestibular screening in this population.