Experimental traumatic brain injury

Traumatic brain injury, a leading cause of death and disability, is a result of an outside force causing mechanical disruption of brain tissue and delayed pathogenic events which collectively exacerbate the injury. These pathogenic injury processes are poorly understood and accordingly no effective neuroprotective treatment is available so far. Experimental models are essential for further clarification of the highly complex pathology of traumatic brain injury towards the development of novel treatments. Among the rodent models of traumatic brain injury the most commonly used are the weight-drop, the fluid percussion, and the cortical contusion injury models. As the entire spectrum of events that might occur in traumatic brain injury cannot be covered by one single rodent model, the design and choice of a specific model represents a major challenge for neuroscientists. This review summarizes and evaluates the strengths and weaknesses of the currently available rodent models for traumatic brain injury

Supraorbital cutaneous blood flow rate during carotid endarterectomy

Background: The supraorbital skin region is supplied by the supraorbital artery, which is a branch of the internal carotid artery. The supraorbital cutaneous blood flow rate may therefore be influenced by changes in the internal carotid artery flow during carotid endarterectomy. Methods: The supraorbital cutaneous blood flow rate was measured by the application of heat to the skin and following the subsequent dissipation of the heat in seven patients undergoing carotid endarterectomy. At the same time, the oxygenation in the right and left frontal region was monitored by near-infrared spectroscopy (NIRS). Results: During cross-clamping of the carotid artery, the ipsilateral NIRS-determined frontal oxygenation tended to decrease [67 ± 13% to 61 ± 11% (P = 0.06); contralateral 68 ± 11% to 66 ± 8%] as did the supraorbital cutaneous blood flow rate from 56 ± 23 to 44 ± 7 ml 100g-1min-1. With the opening of the external carotid artery, the NIRS-determined frontal oxygenation reversed to 66 ± 8% (P &lt; 0.05) on the ipsilateral side, with no significant change on the contralateral side and the supraorbital cutaneous blood flow rate increased to 53 ± 11 (P &lt; 0.05). Opening of the internal carotid artery did not significantly affect the NIRS (67 ± 8% and 69 ± 9% ipsilateral, contralateral), but the supraorbital cutaneous blood flow rate increased to 88 ± 10ml 100g-1min-1 (P &lt; 0.001). Conclusions: Cross-clamping of the internal carotid artery affects the supraorbital cutaneous blood flow rate as well as the frontal lobe oxygenation.</p

Brain Tissue Oxygen Monitoring

Cerebral brain tissue oxygen monitoring (PbtO2) is an increasingly used monitoring technique in severe TBI intensive care management. It yields a continuous regional measurement of oxygen abundance in cerebral tissue and is used in combination with ICP monitoring to guide interventions in patients at risk of cerebral ischemia