NEURALGIA DE ARNOLD
Introduction: Cluster headache, the most painful of the primary headaches, is a strictly unilateral headache that occurs in association with cranial autonomic features and, in most patients, has a striking circannual and circadian periodicity. Its pathophysiology is cloudy and complex, and a unifying explanation is not yet available. Objectives: To review and to discuss the most relevant aspects of cluster headache. Methods: The available literature was reviewed and analyzed, and its aspects considered to be relevant are discussed. Comments and Conclusions: The involvement of both central and peripheral pathways results in the unique features of cluster headache regarding its periodicity and associated autonomic features, resulting in one of the most complex, intriguing and fascinating conditions known by medicine.