Division of Anaesthesia, Addenbrooke’s Hospital, University of Cambridge, UK
Jonathan Coles is a Consultant working within the Neurosciences Critical Care Unit (NCCU) at Addenbrooke’s Hospital and Lecturer within the University Department of Anaesthesia, University of Cambridge, UK. He completed his clinical and research training in Cambridge, and was awarded a PhD in the field of neuro-imaging following clinical head injury based within the NCCU and Wolfson Brain Imaging Centre (WBIC) in Cambridge in 2004. He conducts a program of research that examines mechanisms responsible for secondary neuronal injury, their temporal profile, and implications for eventual neurocognitive recovery following traumatic brain injury.
Pathophysiology of traumatic brain injury
Oxygen-15 positron emission tomography (PET) following early traumatic brain injury (TBI) has identified a variable, but significant, volume of reversible ischemia despite adequate surgical and intensive care management. In addition, severe derangements in metabolism and tissue hypoxia can occur despite adequate blood flow and oxygenation. This is consistent with mitochondrial dysfunction, microvascular injury and a failure of oxygen delivery leading to tissue hypoxia and metabolic crisis. PET imaging studies using a variety of different ligands demonstrate evidence of tissue hypoxia, non-ischaemic hyperglycosis, inflammation, excitotoxocity and selective neuronal loss following TBI. Such processes may result from, or lead to, evidence of spreading depolarization, peri-infarct depolarisations and seizures which are associated with poor outcome. Understanding the temporal and spatial profile of pathophysiological derangements in clinical TBI may help refine current management and provide targets for novel therapeutic interventions that aim to improve functional outcome for patients.