Headaches and sinus disease: the endoscopic approach.

Headaches can be of sinugenic origin even if this cause may not be suspected from the case history. Endoscopy of the lateral nasal wall with rigid cold light endoscopes in combination with polytomography or computed tomography usually will reveal the underlying causes hidden from the unaided eye, the operating microscope, and standard x-ray examination. Small lesions in the lesser cells of the ethmoid complex may give rise to headaches, especially when located in the key areas of the ethmoid infundibulum or frontal recess. Many anatomic variations of the structures in the middle meatus can narrow the stenotic clefts even more and thus predispose to more or less intense contact of opposing mucosal surfaces. This may impede or block ventilation and drainage of the ethmoid and surrounding larger sinuses and thus affect those as well. After identification of these underlying causes, functional endoscopic sinus surgery with usually minimal operations often can provide dramatic relief of symptoms that may have been present for months or even years. The neuropeptides recently were newly identified as a group of mediators besides the neurotransmitters noradrenalin and acetylcholine. Substance P (SP) is one of the most important neuropeptides that we can identify in the human nasal mucosa. It mediates pain impulses to the cortex via afferent C fibers. Simultaneously from polymodal receptors in the nasal mucosa, local reflexes are mediated by SP via an axon reflex, causing vasodilatation, plasma extravasation ("neurogenic edema"), and hypersecretion. The receptors can be stimulated by chemical and caloric irritants and also mechanical irritants such as pressure. The pressure exerted on nasal mucosa by polyps or mucosal swelling due to other reasons in the ethmoid clefts, cells, and narrow spaces apparently can be enough to trigger an SP-mediated pain sensation via afferent C fibers. Over the axon reflex an initially small lesion may lead in a vicious circle to quite significant symptoms. The model of "referred pain" explains why the pain is not necessarily felt at its origin, but may be projected onto corresponding dermatomes. The pain-mediating function of SP can be blocked selectively by capsaicin, the pungent component of red pepper, which leads to desensitization of the receptors and degeneration of the afferent C fibers without affecting other sensory qualities. In patients with vasomotor rhinitis we were able to block all the patients' symptoms including headaches by topical administration of capsaicin. After identification of underlying causes with endoscopy and CT, lesions and contact areas should be operated upon if medical treatment fails.(ABSTRACT TRUNCATED AT 400 WORDS)