[Why cerebral infarction is an emergency].

The three main criteria for a medical emergency: sudden onset, poor prognosis and possibility of an effective medical treatment apply to cerebral infarction which is the end result of a focal ischemia, occurring all the more rapidly than perfusion pressure is low. Studies devoted to experimental cerebral infarction as well as to thrombolysis in human have shown that the therapeutic window to save the penumbral tissue is very short, presently 3 hours in human for intra venous thrombolysis but with considerable individual variations best assessed by MRI diffusion-perfusion. Caring for the patient who has a cerebral infarction is an emergency because it is necessary, in the very first hours, to properly diagnose the infarct and its etiopathogenesis, to detect the vital manifestations to prevent the general complications, to start an antithrombotic treatment, to establish a vital and functional prognosis, to apply in due time the rare surgical or intra-arterial thrombolytic treatments and to start secondary prevention in patients with transient ischemic attacks.