Kernspintomographische Untersuchungen nach "controlled cortical impact injury"

by

Objective: The controlled cortical impact injury (CCII) device, as described by Dixon 1991, was used to investigate the brain tissue damage in an animal model of severe traumatic brain injury. Magnetic resonance imaging (MRI) techniques including diffusion weighted imaging (DWI) have been applied to analyse the time course and the characteristics of edema formation and to detect blood-brain-barrier disruption. Furthermore MRI has been used to investigate a neuroprotective effect of the NO-synthase pathway modulator lubeluzole, which has proved markedly beneficial in a model of cerebral ischemia in rats. Material and Methods: a left parieto-temporal cortical contusion was inflicted upon 46 Sprague Dawley rats. Animals have been examined up to 7 days following trauma by MRI. 36 animals have been administered lubeluzole resp. placebo. Results: The most pronounced edema formation has been shown in T2-weighed imaging at 24 - 48 hours post trauma. DWI was able to distinguish between a contusion core and a contusion rim. The contusion core was marked by a decrease in the apparent diffusion coefficient (ADC) up to 48 hours post trauma, indicating cytotoxic edema, whereas the contusion rim has been characterised by vasogenic edema, as indicated by ADC-increase over the entire investigation period. In T1-weighted imaging contrast agent extravasation indicated a sustained blood brain barrier disruption up to 7 days after trauma. Compared to placebo administered rats in lubeluzole-treated animals no significant differences in ADC-changes, edema-extension or physiological parameters as blood pressure, intracranial pressure or brain swelling could be demonstrated. Conclusion: CCII induced traumatic brain injury is characterised by a cytotoxic edema up to 48 hours encircled by a vasogenic contusion rim accompanied by a sustained blood brain barrier disruption. In the model of CCII lubeluzole did not reveal a neuroprotective effect in the applied dosage.