Jugular venous reflux

Cerebral venous outflow impairment is known to produce cerebral dysfunction in many clinical and animal studies. However, knowledge and understanding of the cerebral venous system is far less than that of the arterial system. The internal jugular vein, which is easily observed by color-coded Doppler sonography, is one of the main tracts for cerebral venous drainage. Recently, internal jugular venous reflux has been found to be related to several neurologic disorders. These associations suggest that the mechanism of these disorders is related to cerebral venous outflow impairment. In this article, we will briefly introduce the cerebral venous system and extracranial venous drainage pathway, then specifically review the characteristics of the internal jugular vein, its branches, and the hemodynamic factors involved in internal jugular venous reflux.