Migraine has been traditionally considered a non-progressive, paroxysmal disorder with no brain abnormalities between attacks. We used diffusion tensor imaging to examine interictal diffusion properties of the brains of migraineurs with aura, migraineurs without aura and matched healthy controls. Areas of lower fractional anisotropy (FA) were present in migraineurs along the thalamocortical tract. In addition, migraineurs with aura had lower FA in the ventral trigeminothalamic tract, and migraineurs without aura had lower FA in the ventrolateral periaqueductal gray matter. Our results indicate the presence of permanent interictal changes in migraineurs, pointing to an effect of migraine on the trigeminal somatosensory and modulatory pain systems.

Clinical and pathophysiological evidences connect migraine and the cerebellum. Literature on documented cerebellar abnormalities in migraine, however, is relatively sparse. Cerebellar involvement may be observed in 4 types of migraines: in the widespread migraine with aura (MWA) and migraine without aura (MWoA) forms; in particular subtypes of migraine such as basilar-type migraine (BTM); and in the genetically driven autosomal dominant familial hemiplegic migraine (FHM) forms. Cerebellar dysfunction in migraineurs varies largely in severity, and may be subclinical. Purkinje cells express calcium channels that are related to the pathophysiology of both inherited forms of migraine and primary ataxias, mostly spinal cerebellar ataxia type 6 (SCA-6) and episodic ataxia type 2 (EA-2). Genetically driven ion channels dysfunction leads to hyperexcitability in the brain and cerebellum, possibly facilitating spreading depression waves in both locations. This review focuses on the cerebellar involvement in migraine, the relevant ataxias and their association with this primary headache, and discusses some of the pathophysiological processes putatively underlying these diseases.

Since visual aura is usually described as expanding zigzag lines, neurones involved with the perception of line orientation may initiate this phenomenon. A visual incongruent line stimulation protocol was developed to obtain functional magnetic resonance images (fMRI) interictally in 5 female migraine patients with typical fortification spectra and in 5 normal matched controls. Activation in the visual cortex was present contralateral to the side of stimulation in 4 of 5 patients, notably in the extrastriate visual cortex. In 4 of 5 controls activation was observed in the medial and anterior orbitofrontal cortex. In one of them additional activation at the right nucleus accumbens/ventral striatum and right ventral pallidum was present. In the remaining control subject activation was present in the left primary visual cortex. The enhanced interictal reactivity of the visual cortex in migraineurs supports the hypothesis of abnormal cortical excitability as an important pathophysiological mechanism in migraine aura, though the role of specific regions of the visual cortex remains to be explored.

BackgroundMigraine, particularly chronic migraine (CM), is underdiagnosed and undertreated worldwide. Our objective was to develop and validate a self-administered tool (ID-CM) to identify migraine and CM.MethodsID-CM was developed in four stages. (1) Expert clinicians suggested candidate items from existing instruments and experience (Delphi Panel method). (2) Candidate items were reviewed by people with CM during cognitive debriefing interviews. (3) Items were administered to a Web panel of people with severe headache to assess psychometric properties and refine ID-CM. (4) Classification accuracy was assessed using an ICHD-3β gold-standard clinician diagnosis.ResultsStages 1 and 2 identified 20 items selected for psychometric validation in stage 3 (n = 1562). The 12 psychometrically robust items from stage 3 underwent validity testing in stage 4. A scoring algorithm applied to four symptom items (moderate/severe pain intensity, photophobia, phonophobia, nausea) accurately classified most migraine cases among 111 people (sensitivity = 83.5%, specificity = 88.5%). Augmenting this algorithm with eight items assessing headache frequency, disability, medication use, and planning disruption correctly classified most CM cases (sensitivity = 80.6%, specificity = 88.6%).DiscussionID-CM is a simple yet accurate tool that correctly classifies most individuals with migraine and CM. Further testing in other settings will also be valuable.

More than 16 years after the first description of hemicrania continua (HC), its aetiology and pathogenesis remain obscure. Clinically, HC is considered a syndrome with two pivotal characteristics: (i) strictly unilateral (moderate, fluctuating, relatively long-lasting) headache; and (ii) absolute response to indomethacin. HC is further characterized by some ancillary, but mostly "negative", features such as: (iii) relative paucity of accompaniments; and (iv) lack of precipitating factors. The female preponderance is also remarkable, although not diagnostic in the solitary case. Finally, a non-specific, but remarkable feature is the temporal pattern. HC may present as a remitting or chronic (continuous) headache. In HC, unilaterality and absolute response to indomethacin are considered crucial diagnostically. Existing controversy, such as regarding atypical features, particularly the so-called "HC resistant to indomethacin", is discussed. The nature of hemicrania with negative indomethacin response remains most unclear; it may not belong to the HC cycle at all. Accordingly, we propose that the typical clinical picture of HC, including an absolute response to indomethacin, be termed Hemicrania continua vera. More or less analogous, but indomethacin-resistant, clinical pictures can provisionally be termed Hemicrania generis incerti (of undetermined nature), provided other diagnostic possibilities have been ruled out. The differential diagnosis of HC vs. other unilateral headaches is commented on. Previous attempts at classification of HC into the group chronic daily headache (CDH) are discussed. The only acceptable "link" of HC with the other headaches classified as CDH is the temporal pattern (which is a non-specific feature). HC is probably pathophysiologically different from the others disorders classified under CDH. Conversely, HC and chronic paroxysmal hemicrania share many common features, including the absolute response to indomethacin. HC should probably be included in the IHS group 3.

BackgroundChronic pain disorders are presumed to induce changes in brain grey and white matters. Few studies have focused CNS alterations in trigeminal neuralgia (TN).MethodsThe aim of this study was to explore changes in white matter microstructure in TN subjects using diffusion tensor images (DTI) with tract-based spatial statistics (TBSS); and cortical thickness changes with surface based morphometry. Twenty-four patients with classical TN (37-67 y-o) and 24 healthy controls, matched for age and sex, were included in the study.ResultsComparing patients with controls, no diffusivity abnormalities of brain white matter were detected. However, a significant reduction in cortical thickness was observed at the left cuneus and left fusiform cortex in the patients group. The thickness of the fusiform cortex correlated negatively with the carbamazepine dose (p = 0.023).ConclusionsSince the cuneus and the fusiform gyrus have been related to the multisensory integration area and cognitive processing, as well as the retrieval of shock perception conveyed by Aδ fibers, our results support the role of these areas in TN pathogenesis. Whether such changes occurs as an epiphenomenon secondary to daily stimulation or represent a structural predisposition to TN in the light of peripheral vascular compression is a matter of future studies.

-Cervicocogenic headache (CeH) is a relatively common disorder. Although no ideal treatment is available so far, blockades in different structures and nerves may be temporarily effective. We studied the effects of 1-2 mL 0.5% bupivacaine injection at the ipsilateral greater occipital nerve (GON) in 41 CeH patients. The pain is significantly reduced both immediately and as long as 7 days after the blockade. The improvement is less marked during the first two days, a phenomenon we called "tilde pattern". GON blockades may reduce the pool of exaggerated sensory input and antagonize a putative "wind-up-like effect" which may explain the headache improvement.KEY WORDS: anaesthetic blockade, bupivacaine, cervicogenic headache, greater occipital nerve. Bloqueio do nervo occipital maior na cefaléia cervicogênicaRESUMO -A cefaléia cervicogênica (CeH) é condição relativamente comum. Embora ainda não exista tratamento ideal, a CeH pode ser temporariamente controlada mediante o bloqueio de diferentes estruturas cervicais, incluindo nervos. Neste estudo, 41 pacientes com CeH tiveram o nervo occipital maior (GON) ipsilateral bloqueado com 1-2 ml de bupivacaína a 0,5%. A dor foi significativamente reduzida tanto imediatamente quanto até 7 dias após o bloqueio. A melhora foi menos marcada nos primeiros dois dias, determinando um padrão que nós denominamos "tilde pattern" (padrão til). É possível que o bloqueio do GON reduza a quantidade de aferências sensitivas exageradas e antagonize um eventual efeito "wind-up", justificando a melhora da cefaléia por prazos mais longos. PALAVRAS-CHAVE: bloqueio anestésico, bupivacaína, cefaléia cervicogênica, nervo occipital maior.

Chronic migraine is a condition with significant prevalence all around the world and high socioeconomic impact, and its handling has been challenging neurologists. Developments for understanding its mechanisms and associated conditions, as well as that of new therapies, have been quick and important, a fact which has motivated the Latin American and Brazilian Headache Societies to prepare the present consensus. The treatment of chronic migraine should always be preceded by a careful diagnosis review; the detection of possible worsening factors and associated conditions; the stratification of seriousness/impossibility to treat; and monitoring establishment, with a pain diary. The present consensus deals with pharmacological and nonpharmacological forms of treatment to be used in chronic migraine.