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

## TL;DR

This review explores how brain injuries disrupt blood flow control and autonomic functions, which can worsen patient outcomes.

## Contribution

The paper highlights a bidirectional relationship between cerebral autoregulation and autonomic dysfunction after TBI.

## Key findings

- Impaired cerebral autoregulation and autonomic dysfunction are common after TBI.
- These phenomena are distinct but closely related, with a bidirectional relationship.
- Their intersection offers a potential target for improving TBI patient outcomes.

## Abstract

Introduction: 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. Aims: 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. Findings: 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. Conclusions: 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.