[Post-traumatic intracranial hypertension and biochemical disorders: cases and consequences]

Increased intracranial pressure is a risk factor which may result in secondary brain damage, and affect neurological outcome in head injured patients. In case of diffuse brain lesions, elevated intracranial pressure is characterised by two important features. First, it results from vasogenic or cellular oedema, or from an increase in cerebral blood volume. Second, it is strongly associated to biochemical disorders. The latter may be considered as a direct consequence of the initial traumatic impact, mediating factors of the secondary neurological lesion and the biochemical result of cerebral ischaemia. They contribute to increased intracranial pressure and ischaemia by inducing physiological disorders and cell lesions. They also reflect the degree of cerebral ischaemia. Cerebral acidosis, free radicals and excitatory amicoacids are the main biochemical disorders implicated in this vicious circle leading to neuronal death.