Insights on the terminology and on some pathophysiological aspects of cluster headache and related conditions

IntroductionCluster headache and the more recently reported “related conditions”, namelyChronic Paroxysmal Hemicrania, Short-lasting, unilateral, Neuralgiform Headachewith Conjunctival Injection and Tearing (SUNCT) Syndrome and (possibly also)Hemicrania Continua, are one of the fascinating groups of conditions in Neurologywhose cardinal features are the almost absolute unilaterality of pain, its excruciatingseverity, besides the prominent mainly facial autonomic disturbances and overall theintriguing biorhythmicity.Beyond any doubt, the progress of our knowledge about themechanisms of these conditions has been considerable, but there is always room forreflection on where we are and where we can go.ObjectiveThe objectives of the present study are to analyze the metrics of publications onthe pathophysiology of these conditions, to explore in detail how proper the term”Trigeminal Autonomic Cephalgia” is, and to comment on their numerous synonyms.CommentMuch is needed to know the exact structures and circuitry involved in the pathophysiology of these conditions; accordingly, a non-compromising and just descriptive termmight be useful. Along this line of reasoning and bearing in mind the cardinal pointsof such conditions, namely, pain in the trigeminal territory, prominent autonomicsymptoms, prominent chronobiological features, and the excruciating character ofthe pain, a terminological possibility would be: Unilateral with Prominent Rhythmicityand Autonomic Symptoms Excrutiating Cephalgia (UPRASEC).