[Chronic and Refractory Migraine: How to Diagnose and Treat]. / Enxaqueca Crónica e Refratária: Como Diagnosticar e Tratar.

Migraine is highly prevalent and carries a significant personal, social and economic burden. It is the second cause of disability (years living with disability) worldwide and the first cause under 50 years of age. Chronic migraine (occurring for more than 15 days a month) and refractory migraine (treatment resistant), especially when there is also analgesic overuse, are the most disabling forms of migraine. These three disorders (chronic migraine, refractory migraine and medication overuse headache) are particularly difficult to treat. This article reviews their epidemiology, clinical presentation, diagnostic criteria, risk factors, comorbidities and social and personal impact. The therapeutic options available are discussed and focused on a multidisciplinary approach, non-pharmacological interventions treatment of comorbidities and avoiding analgesic overuse. Prophylactic treatments are mandatory and include the oral prophylactic treatments (topiramate), botulinum toxin type A and the novel monoclonal antibodies against calcitonin gene related peptide or its receptor, which are the first migraine preventive medicines developed specifically to target migraine pathogenesis. In refractory cases, multiple therapies are required including neurostimulation.

A enxaqueca é uma cefaleia muito prevalente na população com importantes custos pessoais, sociais e económicos e é a segunda causa a nível mundial de anos vividos com incapacidade. As suas variantes, crónica (aquela que ocorre mais de 15 dias por mês) e refratária (resistente ao tratamento), sobretudo quando se complicam de uso excessivo de analgésicos, embora mais raras, constituem as formas que causam maior incapacidade. Os autores revêm estes três tipos de cefaleias (enxaqueca refratária, enxaqueca crónica e cefaleia secundária a utilização excessiva de analgésicos) que constituem um grupo de cefaleias de difícil terapêutica. São revistos a epidemiologia, os aspetos clínicos, os critérios de diagnóstico, as comorbilidades, os fatores de agravamento e o impacto destas cefaleias sobre a qualidade de vida dos doentes. O tratamento de cada uma destas entidades é abordado, ressalvando a importância de uma abordagem abrangente, considerando o tratamento das comorbilidades, a utilidade de medidas não farmacológicas, o imperativo de evitar o abuso de analgésicos e a necessidade absoluta de tratamento profilático. São revistos os diferentes tratamentos profiláticos disponíveis (e a evidência científica da sua eficácia), tais como os fármacos preventivos orais (neuromodeladores como o topiramato), a toxina botulínica tipo A e os novos medicamentos preventivos para a enxaqueca (anticorpos monoclonais que atuam sobre o péptido relacionado com o gene da calcitonina ou o seu recetor, e que são os primeiros medicamentos preventivos desenvolvidos especificamente para atuar na fisiopatogenia da enxaqueca. Para os casos refratários são consideradas outras alternativas terapêuticas como a neuroestimulação.

CADASIL: MRI may be normal in the fourth decade of life - a case report.

Background Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) manifests by migraine with aura, cerebral ischemic events, mood disturbances and dementia. Brain MRI lesions typically precede the symptoms from 10 to 15 years and previous evidence showed all CADASIL patients above 35 years old have an abnormal MRI, supporting the clinical diagnosis. Case results We present a 37-year-old female patient with migraine without aura, a family history of CADASIL, normal brain 3-Tesla MRI and normal skin biopsy, even though a pathogenic NOTCH3 gene mutation (allele 2, exon 11, c.1672 C\gtT, p.Arg558Cys) was detected. Conclusions When CADASIL is strongly suspected, a normal brain MRI, even in the fourth decade of life, does not rule out the diagnosis and should not discourage the genetic test.

A dominant-negative mutation in the TRESK potassium channel is linked to familial migraine with aura.

Migraine with aura is a common, debilitating, recurrent headache disorder associated with transient and reversible focal neurological symptoms. A role has been suggested for the two-pore domain (K2P) potassium channel, TWIK-related spinal cord potassium channel (TRESK, encoded by KCNK18), in pain pathways and general anaesthesia. We therefore examined whether TRESK is involved in migraine by screening the KCNK18 gene in subjects diagnosed with migraine. Here we report a frameshift mutation, F139WfsX24, which segregates perfectly with typical migraine with aura in a large pedigree. We also identified prominent TRESK expression in migraine-salient areas such as the trigeminal ganglion. Functional characterization of this mutation demonstrates that it causes a complete loss of TRESK function and that the mutant subunit suppresses wild-type channel function through a dominant-negative effect, thus explaining the dominant penetrance of this allele. These results therefore support a role for TRESK in the pathogenesis of typical migraine with aura and further support the role of this channel as a potential therapeutic target.