Cerebral Ischemia and Infarction: Global Ischemia: A general drop in blood pressure of sufficient magnitude and duration will deprive nervous system tissue of glucose (ischemia) and oxygen (anoxia). This will result in the death of cells and atrophy of brain tissue over a period of days, referred to as cerebral infarction. A number of diseases will decrease cardiac output and thus produce general brain ischemia. These include cardiac arrest and pulmonary embolism.

General ischemia associated with these diseases usually results in loss of consciousness and coma. A period of hypotension or periodic drops in blood pressure may produce infarction of the borders between major arterial perfusion areas (watershed areas).