Viggiano A, Manara R, Conforti R, Paccone A, Secondulfo C, Lorusso L, Sbordone L, Di Salle F, Monda M, Tedeschi G, Esposito F
Department of Medicine and Surgery, University of Salerno, Via S. Allende, 84081 Baronissi (Salerno), Italy.
MRI Center SUN-FISM, Institute for Diagnosis and Care "Hermitage Capodimonte", Via Cupa delle Tozzole, 2, 80145 Naples, Italy; Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, Second University of Naples, Piazza L. Miraglia 2, 80138 Naples, Italy.
Neuroscience. 2015 Dec 17;311:75-80. doi: 10.1016/j.neuroscience.2015.10.017. Epub 2015 Oct 21.
Understanding mechanisms for vessel tone regulation within the trigeminal nuclei is of great interest because some headache syndromes are due to dysregulation of such mechanisms. Previous experiments on animal models suggest that mastication may alter neuron metabolism and blood supply in these nuclei. To investigate this hypothesis in humans, arterial spin-labeling magnetic resonance imaging (MRI) was used to measure blood perfusion within the principal trigeminal nucleus (Vp) and in the dorsolateral-midbrain (DM, including the mesencephalic trigeminal nucleus) in healthy volunteers, before and immediately after a mastication exercise consisting of chewing a gum on one side of the mouth for 1 h at 1 bite/s. The side preference for masticating was evaluated with a chewing test and the volume of the masseter muscle was measured on T1-weighted MRI scans. The results demonstrated that the mastication exercise caused a perfusion increase within the Vp, but not in the DM. This change was correlated to the preference score for the side where the exercise took place. Moreover, the basal Vp perfusion was correlated to the masseter volume. These results indicate that the local vascular tone of the trigeminal nuclei can be constitutively altered by the chewing practice and by strong or sustained chewing.
了解三叉神经核内血管张力调节机制具有重要意义，因为一些头痛综合征是由于这些机制的调节异常所致。先前对动物模型的实验表明，咀嚼可能会改变这些核内的神经元代谢和血液供应。为了在人体中研究这一假设，在健康志愿者进行一项咀嚼运动前后，采用动脉自旋标记磁共振成像（MRI）测量其三叉神经主核（Vp）和背外侧中脑（DM，包括中脑三叉神经核）的血液灌注。该咀嚼运动为在口腔一侧以每秒1次的频率咀嚼口香糖1小时。通过咀嚼测试评估咀嚼的侧别偏好，并在T1加权MRI扫描上测量咬肌体积。结果表明，咀嚼运动导致Vp内灌注增加，但DM内未增加。这种变化与运动发生侧的偏好评分相关。此外，Vp的基础灌注与咬肌体积相关。这些结果表明，咀嚼练习以及强烈或持续的咀嚼可使三叉神经核的局部血管张力发生持续性改变。
