[So-called atypical facial neuralgias]

According to new findings, Sluder's neuralgia, cluster headache and sympathetic neuralgia in the face are likely to be of vascular origin from the branches of the external carotid artery. These vessels receive multiple innervation: sympathetic (constricting), parasympathetic (vasodilator) and through C-fibre liberating substance P. In addition enkephalins, known to act as antagonists to substance P, have been found in the vessels of the external and the internal carotid artery. The equilibrium between sympathetic and parasympathetic fibres, between C-fibres and local enkephalins may be disturbed by various mechanisms. An excess of the sympathetic or parasympathetic activity may not only cause changes of vascular tone but also induce the liberation of substance P. In general, the atypical facial neuralgias are self-limiting or may present with an intermittent course. In chronic and drug-resistant cases surgical interventions can be helpful. The trigeminal nerve is the first target, as all C-fibres from the head, including the vessels, reach the trigeminal nerve. Of less importance for surgical intervention is the pterygopalatine ganglion, which is not only parasympathetic, but contains also sympathetic and C-fibres from the mucosa of nose and orbit.