Content area
Full Text
NEWS & VIEWS
M I G R A I N E
Are migraine endophenotypes needed?
Refers to Barbanti, P. etal. The phenotype of migraine with unilateral cranial autonomic symptoms documents increasedperipheral and central trigeminal sensitization. A case series of 757 patients. Cephalalgia http://dx.doi.org/10.1177/0333102416630579
Web End =http://dx.doi.org/10.1177/0333102416630579
In a recent study, Piero Barbanti and col leagues1 investigated in detail the charac teristics of migraine with unilateral cranial autonomic symptoms (UASs), a proposed migraine endophenotype. The authors reported that the prevalence of many symp toms differed between migraine with and without UASs, and suggested that the differ ences would enable distinction between this endophenotype and other types of migraine. Whether their data are sufficient to support such a conclusion is, however, debatable, and raises the question of whether such classifications of migraine are useful.
Migraine and other headaches have been defined and classified in three successive edi tions of the International Headache Societys International Classification of Headache Disorders (ICHD); the most recent edition has been published as a beta version for field testing2. This classification has been translated into many languages and is uni versally accepted; its unambiguous diag nostic criteria for all headache entities have greatly improved the standards of diagnosis. Development of the ICHD3 beta version included a hot debate over whether sub division of the defined migraine types would be advantageous. Ultimately, the number of ways in which the divisions could have been made were too numerous to make this subdivision practical. For example, poten tial subdivisions include menstrual versus
symptoms: unilateral conjunctival injection, lacrimation, nasal congestion, rhinorrhea, ptosis, eyelid swelling or forehead and/or facial sweating. 37.4% of participants said that they experienced at least one of the autonomic symptoms. The majority of these patients (53.0%) experiencedonly one UAS, fewer (38.4%)experienced two, and very few (8.8%) experienced more than two; by con trast, in cluster headache, several autonomic symptoms are typically experienced during an attack. Additionally, Barbanti and col leagues made no attempt to score the inten sity of UASs, so the symptoms might have been more subtle than in clusterheadache.
Comparison of patients who experienced UASs with those who did not showed that 15 of 76 recorded clinical features had a sig nificantly higher prevalence in patients who said...