Traumatic brain injury represents one of the most important epidemics of our society with devastating social, economic and health consequences. Thanks to the technological advancements in medicine the last 50 years there have been huge steps in the exploration of the pathophysiologic mechanisms of traumatic brain injury (TBI). Neuromonitoring today is an indispensable tool in the study and management of the brain injured patients.
The purpose of this thesis is to investigate the application of near infrared light in TBI. We have reviewed the application of near infrared spectroscopy (NIRS) in the detection of intracranial haematomas. With a cross study negative predictive value of 90% and a positive predictive value of 77%, NIRS did not meet the requirements set by this review either as a diagnostic or triage tool. To address this an evolved hand-held NIRS device was then tested in the emergency department of St Mary’s Hospital. We have recruited 205 patients; intracranial haematomas of volume>3.5ml, and deep<2.5cm from the surface of the brain, the sensitivity was found to be 89% and the negative predictive value 93.9%. It is demonstrated that the infrared scanner can quickly rule out the presence of an intracranial clot.
In this thesis, we also examined the application of NIRS as a neuromonitroing method in severe TBI patients in intensive care unit investigating the non-invasiveness detection of spreading depolarisations. In the first part, we recruited six patients, demonstrating that application of NIRS as continuous monitoring is feasible in intensive care unit and also detected in 4 patients local haemodynamic changes which may represent the imprint of spreading depolarisation. In the second part, we recruited 9 patients with synchronous application of NIRS and invasive electrodes for the detection of spreading depolarisations. Finally, we demonstrated the non-invasive detection of spreading depolarisations using NIRS in TBI patient. This thesis has confirmed the promising nature of NIRS technology in traumatic brain injury, suggesting that it is worth expanding the investigation in other acute brain pathologies.