Our literature review reveals that these social, emotional, and clinical misperception elements should be considered in the decision-making processes to help the triad develop functional forms of care at this final stage of life. Copyright © 2011 John Wiley & Sons, Ltd.

BackgroundMedication overuse headache (MOH) is a very disabling and costly disorder due to indirect costs, medication and healthcare utilization. The aim of the study was to describe general demographic and clinical characteristics of MOH, along with the national referral pathways and national painkillers distribution in several European and Latin American (LA) Countries.MethodsThis descriptive cross-sectional observational study included 669 patients with MOH referred to headache-centers in Europe and LA as a part of the COMOESTAS project. Information about acute medication and healthcare utilization were collected by extensive questionnaires, supplemented with structured patient interviews.ResultsTriptans were overused by 31 % European patients and by 6 % in LA (p < 0.001), whereas ergotamines were overused by 4 % in Europe and 72 % in LA (p < 0.001). Simple analgesics were overused by 54 % in Europe and by 33 % in LA (p < 0.001), while combination-analgesics were more equally overused (24 % in Europe and 29 % in LA). More European patients (57 %) compared with LA patients (27 %) visited general practitioners (p < 0.001), and 83 % of European patients compared to 38 % in LA consulted headache specialists (p < 0.001). A total of 20 % in Europe and 30 % in LA visited emergency rooms (p = 0.007).ConclusionThere are marked variations between LA and Europe in healthcare pathways and in acute medication overuse regarding patients with MOH. This should be considered when planning prevention campaigns against MOH.Electronic supplementary materialThe online version of this article (doi:10.1186/s10194-016-0612-2) contains supplementary material, which is available to authorized users.

BackgroundData on the characteristics of Medication Overuse Headache (MOH) in Latin American (LA) are scarce. Here we report the demographic and clinical features of the MOH patients from Argentina and Chile enrolled in the multinational COMOESTAS project in the period 2008–2010.MethodsThe LA population was formed by 240 MOH subjects, 110 from Chile and 130 from Argentina, consecutively attending the local headache centres. In each centre, specifically trained neurologist interviewed and confirmed the diagnosis according to the ICHD-II criteria. A detailed history was collected on an electronic patient record form.ResultsThe mean patient age was 38.6 years, with a female/male ratio of 8:2. The mean time since onset of the primary headache was 21 years, whereas duration of MOH was 3.9 years. The primary headache was migraine without aura in 77.5 % and migraine with aura in 18.8 %. Forty two % of the patients self-reported emotional stress associated with the chronification of headache; 43.8 % reported insomnia. The most overused medications were acute drug combinations containing ergotamine (70 %), NSAIDs (33.8 %) and triptans (5.4 %).ConclusionThough little described, MOH is present also in LA, where it affects mostly women, in the most active decades of life. Some differences emerge as regards the demographic and clinical characteristics of MOH in this population as compared to Europe or Northern America. What seems more worrying about MOH in Argentina and Chile is that most patients overuse ergotamine, a drug that may cause serious adverse events when used chronically. These findings once more underscore the importance of properly diagnose and treat MOH.

Antes del surgimiento de la epigenética, la relación genes-ambiente era explicado bajo la visión de un "determinismo genético". Ambas concepciones, epigenética y determinismo genético, tienen sus ancestros en los conceptos de epigénesis y preformismo que surgieron en los siglos XVII y XIX 3 . Posteriormente, prevaleció la concepción de que tanto el desarrollo como el fenotipo estaban definidos casi exclusivamente por los genes. A comienzos del siglo XX la Genética era considerada la ciencia de la herencia y la Embriología la del desarrollo 4 . Waddington trató de demostrar que ambas disciplinas estaban estrechamente ligadas entre sí y con la evolución, de manera que la explicación del desarrollo desde el genotipo al fenotipo tendrían que necesariamente integrar el conocimiento de ambas ciencias.En las últimas décadas, sus planteamientos se han retomado en una nueva perspectiva. Actualmente se reconoce el papel fundamental que el ambiente extranuclear, extracelular y social ejerce en la modulación de la actividad genética 5 . Los modelos simples aditivos que sugieren que el fenotipo es la suma de los efectos de los genes y del ambiente, no dan respuesta a la realidad 6 . Se propone que los sistemas genéticos son dinámicos o cibernéticos 7 . Al respecto, investigadores 8 han demostrado cómo el nivel socioeconómico modifica la heredabilidad del coeficiente intelectual (CI) de manera no lineal. Estos autores, a diferencia

(Rev Med Chile 2013; 141: 704-709).