Dysautonomia and Systemic Interactions in Traumatic Brain Injury

Following traumatic brain injury (TBI) complex interactions between the nervous system and other organs are frequently encountered. Systemic reactions may be induced by dys-regulation of the hypothalamic-pituitary adrenal (HPA) axis and the autonomic nervous system. Neuro-endocrine disturbances are common and up to 50 % of brain injured Neuro-intensive care (NICU) patients may exhibit a period of relative adreno-cortico insufficiency in the early phase of TBI, which in part may be centrally mediated. Catecholamine surge is thought responsible for cardio pulmonary reactions such as myocardial stunning, and may be an instrumental part of neurogenic pulmonary edema. An imbalance between the parasympathetic and sympathetic nervous system has been identified, and may even effect outcome, but is poorly understood. This is seen both in early and chronic stages of brain injury. Heart rate variability has been implicated as an indicator of dys-autonomic parasympathetic dysfunction, and has in small studies been related to TBI outcome. Recently a clinical definition of Paroxysmal Sympathetic Hyper-activation (PSH) has been suggested and identities as related to patient outcome.

Thus, in TBI the picture of a triad of dysautonomic and hypothalamic-pituitary dysregulation and injury driven inflammation, with a potential of bi-directional cross-talk between central and peripheral immuno- modulators, is emerging. This study will aim to explore and integrate indicators of these three components as to define phenotypes. It will investigate the utility of medically approved (CE) Skin Conductance Algesimeter (Med-Storm ®) in relation to other parameters of physiological stress including, heart rate variability (HRV), intra-cranial pressure reactivity index (PrX), and products of the HPA axis such as, ACTH, adrenaline and nor-adrenaline including break down products, markers of brain trauma driven neuro and systemic inflammation.

The investigators hypothesize that a limited number of composite patterns will emerge and may describe patient phenotypes with differing trajectories.

CRF:

Electronic case report form (eCRF) with pseudo anonymized data via a globally unique personal identifier (GUPI) to secure eCRF platform.