[Physiopathology of meningeal hemorrhage caused by aneurysmal rupture: extracerebral aspects].

Subarachnoid hemorrhage induces a lot of extracerebral disturbances such as: systemic hypertension, electrocardiographic abnormalities both morphological, rhythmic and subendocardial damages; those events have been interpreted as overactivity of the sympathetic nervous system. In biochemical changes, hyponatremia early recognized was referred during a long time to a syndrome of inappropriate secretion of antidiuretic hormone. Hyponatremia is now referred to a cerebral salt-wasting. Hypovolemia often observed supports the use of volemic expansion in the prevention and treatment of ischemic complications associated with ruptured intracranial aneurysms. The hypothalamus which lies in close anatomical proximity to the circle of Willis may be directly influenced by the rupture of a cerebral aneurysm. So, hypothalamic dysfunction may affect pituitary adrenal function sympathetic and parasympathetic activities. The knowledge of all these disturbances, and their mechanisms supports the current strategies for the management of aneurysmal subarachnoid hemorrhage.