Visceral and Somatic Profiles of Needless Pain and Nonpainful Sensations in Idiopathic Headache

The syndromes commonly called idiopathic headaches (IH) are the most frequent painful pathologies. The term derives from the fact that the IH necessarily but not exclusively involve the head area. Having abandoned the etiopathogenetic criterion of classification (vascular and tension headaches) which was proposed many years ago, The International IH Society has introduced a phenomenonological/descriptive classification, which is logically sound considering the idiopathy and clinical multiformity of IH. This classification may be useful until it is possible to substitute it with a nosography based on sure etiological data. The distinction between “chronicized” migraine (migraine attacks with daily intercritical headache) and tension-type headaches perhaps represents the greatest diagnostic difficulty, since the two forms require different therapeutic tools even though they have clinical analogies. In our center we are developing a nosological method to differentiate tension-type headaches from chronicized migraines on the basis of a criterion that is theoretically sound because it draws on the anatomofunctional features of these IH, and practical because it is easy to apply. This method is founded on solid algological knowledge. In fact, the IH are simply the most common manifestations of the spontaneous activation of the sensory/pain transmitting afferences, decodified at the level of the integrative areas as “useless” painful and nonpainful sensations of either a visceral or a somatic type, according to the type of IH. The adjective “idiopathic,” attributed to the IH, refers to the uselessness of the sensations which dominate these syndromes. They are useless because they are not induced by harmful, environmental, or endogenous stimuli, and do not culminate in a passive or active defensive reaction. Pain, a necessary factor for diagnosing the IH, has different semeiological and anatomofunctional features depending on whether it originates in the soma or in the visceral structures. The IH may thus be distinguished into somatogenic (SH) and viscerogenic headaches (VH) on the basis of which anatomofunctional sensitive structures are activated, these being indentifiable through the semeiological features of the pain and nonpainful sensations. In light of this, we may state that the visceral or somatic nature of the pain and, even more, the visceral or somatic nature of the metaesthesias can aid the distinction of the chronicized migraine (VH) from the tension