VENOUS TERRITORIES OF THE BRAIN

The venous return of the cerebral hemispheres is ensured by two system s. The first, superficial system, reaches the peripheral dural sinuses , i.e. the superior sagittal sinus, the lateral sinus and the cavernou s sinus. The second, deep system, corresponds to Galen's vein. Anatomi cal and angiographic data from the literature enable the usual drainag e territory to be defined for each of these collecting vessels. Howeve r, the variability of the superficial sylvian vein and the importance of cortical anastomotic vessels make impossible to delimit precisely t he territory of each peripheral sinus. The functional role played by n umerous centro-peripheral anastomoses is more difficult to assert in e ach individual. It is therefore probable that in the cerebral hemisphe res there is a deep territory balancing the superficial territories.