The aim of this study was to observe whether vasoactive intestinal polypeptide (VIP) participated in the attack of trigeminal neuralgia , and to understand further its pathogenetic mechanism.Methods :Sixteen patients were studied. During the at2 tacks the venous blood was sampled from both the external jugular vein and cubital fossa vein ipsilateral to the pain , and after op2 erations the venous blood from the external jugular vein was sampled again , the external jugular vein blood of eleven normal volun2 teers was collected as the control. Plasma levels of VIP were determined using sensitive radioimmunoassays.Results :During the at2 tacks of trigeminal neuralgia the levels of VIP in the external jugular vein blood were significantly higher than that in the cubital fossa vein blood , postoperative external jugular vein blood and the external jugular vein blood of normal volunteers.Conclusion : VIP indeed participates in the attack of trigeminal neuralgia in the local region , the role of VIP may be relating to enhancing the effects of substance P in local neurogenic inflammation.
