Authors

1. Hwang, Phillip H. PhD, MPH
2. Nelson, Lindsay D. PhD
3. Sharon, Jeffrey D. MD
4. McCrea, Michael A. PhD
5. Dikmen, Sureyya S. PhD
6. Markowitz, Amy J. JD
7. Manley, Geoff T. MD, PhD
8. Temkin, Nancy R. PhD
9. the TRACK-TBI Investigators

Abstract

Objective: To examine the association between hearing impairment and cognitive function after traumatic brain injury (TBI).

Setting: A total of 18 level I trauma centers throughout the United States in the Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study.

Participants: From February 2014 to June 2018, a total of 2697 participants with TBI were enrolled in TRACK-TBI. Key eligibility criteria included external force trauma to the head, presentation to a participating level I trauma center, and receipt of a clinically indicated head computed tomographic (CT) scan within 24 hours of injury. A total of 1267 participants were evaluated in the study, with 216 participants with hearing impairment and 1051 participants without hearing impairment. Those with missing or unknown hearing status or cognitive assessment were excluded from analysis.

Design: Prospective, observational cohort study.

Main Measures: Hearing impairment at 2 weeks post-TBI was based on self-report. Participants who indicated worse hearing in one or both ears were defined as having hearing impairment, whereas those who denied worse hearing in either ear were defined as not having hearing impairment and served as the reference group. Cognitive outcomes at 6 months post-TBI included executive functioning and processing speed, as measured by the Trail Making Test (TMT) B/A and the Wechsler Adult Intelligence Scale, Fourth Edition, Processing Speed Index subscale (WAIS-IV PSI), respectively.

Results: TBI-related hearing impairment had a small but significantly greater TMT B/A ratio than without TBI-related hearing impairment: mean difference (B) = 0.25; 95% CI, 0.07 to 0.43; P = .005. No significant mean differences on WAIS-IV PSI scores were found between participants with and without TBI-related hearing impairment: B = 0.36; 95% CI, -2.07 to 2.60; P = .825.

Conclusion: We conclude that TBI-related hearing impairment at 6 months postinjury was significantly associated with worse executive functioning but not cognitive processing speed.