Early Autonomic Dysfunction Following Severe TBI and Impact on Cerebral Hemodynamics: A Narrative Review

<b>Introduction:</b> Traumatic brain injury (TBI) is a complex condition that may lead to alterations in cerebral hemodynamics. Impairment of cerebral autoregulatory mechanisms, as well as autonomic dysfunction, has been associated with worse patient outcomes after TBI. <b>Aims:</b> The purpose of this narrative review is to synthesize current evidence on impaired cerebral autoregulation, autonomic dysfunction, and their relationship with intracranial pressure in TBI. <b>Findings:</b> Initial studies examining waveform data have found that impaired cerebral autoregulation and autonomic dysfunction are present in a high proportion of patients after TBI. These are distinct but closely related phenomena, with current evidence suggesting a bidirectional relationship. <b>Conclusions:</b> Impaired cerebral autoregulation and autonomic dysfunction are closely associated. The intersection of these mechanisms is a potential target for intervention to improve patient outcomes after TBI. Additional research is needed to further characterize this relationship.