Temporal lobe contusions on computed tomography are associated with impaired 6-month functional recovery after mild traumatic brain injury: a TRACK-TBI study

Introduction: Mild traumatic brain injury (MTBI) can cause persistent functional deficits and healthcare burden. Understanding the association between intracranial contusions and outcome may aid in MTBI treatment and prognosis. Methods: MTBI patients with Glasgow Coma Scale 13–15 and 6-month outcomes [Glasgow Outcome Scale-Extended (GOSE)], without polytrauma from the prospective TRACK-TBI Pilot study were analyzed. Intracranial contusions on computed tomography (CT) were coded by location. Multivariable regression evaluated associations between intracranial injury type (temporal contusion [TC], frontal contusion, extraaxial [epidural/subdural/subarachnoid], other-intraaxial [intracerebral/intraventricular hemorrhage, axonal injury]) and GOSE. Odds ratios (OR) are reported. Results: Overall, 260 MTBI subjects were aged 44.4 ± 18.1-years; 67.7% were male. Ninety-seven subjects were CT-positive and 46 had contusions (41.3%–frontal, 30.4%–temporal, 21.7%–frontal + temporal, 2.2% each-parietal/occipital/brainstem); 95.7% had concurrent extraaxial hemorrhage. Mortality was 0% at discharge and 2.3% by 6-months. GOSE distribution was 2.3%–death, 1.5%–severe disability, 27.7%–moderate disability, 68.5%–good recovery. Forty-six percent of TC-positive subjects suffered moderate disability or worse (GOSE ≤6) and 41.7% were unable to return to baseline work capacity (RTBWC), compared to 29.1%/20.4% for CT-negative and 26.1%/20.9% for CT-positive subjects without TC. On multivariable regression, TC associated with OR = 3.33 (95% CI [1.16–9.60], p = 0.026) for GOSE ≤6, and OR = 4.48 ([1.49–13.51], p = 0.008) for inability to RTBWC. Conclusions: Parenchymal contusions in MTBI are often accompanied by extraaxial hemorrhage. TCs may be associated with 6-month functional impairment. Their presence on imaging should alert the clinician to the need for heightened surveillance of sequelae complicating RTBWC, with low threshold for referral to services.