Cerebral Blood flow Changes During the Mastication

抄録

Cerebral blood flow changes during the mastication were measured by the transcranial Doppler ultrasound (TCD) . The mean blood flow velocities (Vm) of the middle cerebral artery (MCA) in 17 normal subjects were measured before and during the mastication of cooked cleaned rice, uncleaned rice, softbread and French bread. Moreover, the blood flow during continuous grasping of both hands was measured to compare with the blood flow during mastication. The Vm during the load (Vm (during) ) was compared with the prevalue (Vm (pre) ) and the rates of the changes were calculated as [Vm (during) /Vm (pre) ] ×100 (%) . In 10 normal subjects, the Vm of the basilar artery (BA) was measured before and during mastication. In 5 patients, the diameters of the MCA were measured on the angiogram before and during mastication. The rate of flow velocity change during the mastication increased to 124-133%. The flow velocity of the BA did not show significant changes, therefore the increase of the Vm of the MCA was not caused simply by a regular cardiovascular response to increased activity but a more focal effect caused by the brain itself. The diameter of the MCA also showed no significant changes during the mastication. It means not only the flow velocity but also the blood flow volume increased during mastication. The close relationship between cerebral blood flow and mastication was recognized.