Cardiovascular autonomic function and brain imaging

The cardiovascular system is regulated by cortical modulation such as the anterior cingulate gyrus, insular cortex, amygdala as well as the reticular formation of the brainstem, including ventrolateral medulla (vasopressor center). These structures are called as the central autonomic network (CAN), and its dysfunction causes autonomic dysregulation. For example, ventrolateral medulla compression by tortuous or ectatic vessels has been etiologically linked with essential hypertension. In regard to a relationship of the cerebral cortex and autonomic dysfunction, hypoperfusion of the anterior cingulate gyrus may be seen in patients with chronic autonomic failure such as pure autonomic failure. Meanwhile, patients with chronic hypertension may also show hypoperfusion of the anterior cingulate gyrus. These findings indicate that inadequate internal environment such as hypotension and hypertension in long term can reduce activities of the anterior cingulate gyrus. In regard to the insular cortex, a relationship with cardiac events or sudden death has drawn attention but now it may be time to revaluate this relationship. Amygdala also play an important role in autonomic regulation. Patients with bilateral amygdala damage show s poor autonomic response to mental stress which induces emotional change.