(A, B) Variance of clinical outcome measures. (A) Duration of unresponsiveness, defined by time until command-following. (B) Glasgow Outcome Scale–Extended (GOSE) at 6 months after the traumatic brain injury (TBI) explained by the microbleed volume within all nuclei/regions involved in arousal (i.e., thalamus, hypothalamus, basal forebrain, and 17 brainstem nuclei) was higher than the variance explained by the microbleed volume within the control region (i.e., the brainstem excluding the 17 brainstem nuclei involved in arousal). (C, D) Total microbleed volume evaluated in all nuclei/regions involved in arousal across participants versus (C) duration of unresponsiveness (Pearson correlation coefficient r = 0.55, p = 0.06) and (D) GOSE at 6 months after the TBI (r = 0.43, p = 0.16). (E, F) Total microbleed volume evaluated in the control region across participants versus (E) duration of unresponsiveness (Pearson correlation coefficient r = 0.30, p = 0.34) and (F) GOSE at 6 months after the TBI (r = 0.13, p = 0.70).