Validity of self-reported migraine in adolescents and children.

OBJECTIVE: To assess agreement for migraine day between self-report and diagnostic guidelines for children and adolescents using a headache diary. BACKGROUND: Trial guidelines recommend prospective collection of headache features and adoption of migraine day as an outcome measure, but there is no clear consensus on the definition of migraine day. METHODS: This is a secondary analysis of data from two projects-a prospective cohort study validating a pediatric scale of treatment expectancy and a clinical trial of occipital nerve blocks to treat status migrainosus. Participants completed a text message-based diary for 4 or 12 weeks (depending on treatment), and a detailed headache assessment on a random 20% of headache days. Using this assessment, we determined whether a headache day qualified for migraine or probable migraine, based on the International Classification of Headache Disorders, 3rd edition (ICHD-3). RESULTS: Of 122 enrolled children and adolescents, 106 (86.9%) completed ≥1 detailed headache assessment (438 entries). We found moderate agreement between self-reported and ICHD-derived migraine day, with a Cohen's Kappa of 0.50 (positive predictive value [PPV]: 0.66; negative predictive value [NPV]: 0.85; correlation: 0.51). Allowing for ICHD-derived probable migraine significantly increased PPV (0.66 vs. 0.94; 95% CI: 0.57-0.74 vs. 0.90-0.97), but decreased NPV (0.85 vs. 0.293; CI: 0.77-0.90 vs. 0.199-0.40), Cohen's Kappa (0.50 vs. 0.237; CI: 0. 389-0.60 vs. 0.139-0.352), and correlation (r = 0.51 vs. 0.302; CI: 0.41-0.61 vs. 0.192-0.41). Pain severity (OR: 5.7; CI: 2.39-13.8), photophobia (OR: 4.1; CI: 1.02-16.6), and phonophobia (OR: 7.5; CI: 1.95-29.3) were significantly associated with participants' perception of migraine. CONCLUSION: We found only moderate agreement between self-reported and ICHD-derived migraine day, suggesting both measures are not equal but may represent overlapping aspects of migraine as a disease. This highlights the difficulty of applying ICHD criteria to individual attacks. We recommend greater methodological transparency in future research to avoid readers conflating both measures.

CGRP receptor antagonists: A new frontier of anti-migraine medications.

Migraine is a chronic pain condition that affects 12% of the population. Currently, the most effective treatments are the triptans, but they are limited in their efficacy and have potentially deleterious cardiovascular complications. Based on basic science studies over the past decade, a new generation of anti-migraine drugs is now being developed. At the forefront of these studies is a new calcitonin gene-related peptide (CGRP) receptor antagonist that is as effective as triptans in the acute treatment of migraines, without the cardiovascular effects. This review will address the likely mechanisms and therapeutic potential of CGRP receptor antagonists.

Circadian rhythms of dopamine, glutamate and GABA in the striatum and nucleus accumbens of the awake rat: modulation by light.

Using microdialysis, we investigated the circadian rhythms of the extracellular concentrations of dopamine, glutamate and gamma-aminobutyric acid (GABA) in the striatum and nucleus accumbens of the awake rat. Wistar rats were maintained in a 12 hr dark:12 hr light (12:12) cycle for 2 wk before the experiment began. The neurotransmitter levels were measured every 30 min for 30 hr in control (maintaining the 12:12 cycle) or in experimental conditions under a 24-h light period (continuous light) or under a 24-h dark interval (continuous dark). The dopamine metabolites, DOPAC and HVA, and the main serotonin metabolite, 5-HIAA, were measured along with arginine and glutamine under all conditions. In 12:12 conditions, a circadian rhythm of dopamine, glutamate and GABA was found in both the striatum and nucleus accumbens. Again under 12:12 conditions, DOPAC, HVA, 5-HIAA, and arginine, but not glutamine, fluctuated in a circadian rhythm. In the striatum under constant light conditions, there was a circadian rhythm of dopamine, glutamate, GABA, DOPAC and HVA, but not 5-HIAA. By contrast, when the rats were kept under continuous dark, dopamine and its metabolites, DOPAC and HVA (but not glutamate and GABA), did not fluctuate in a circadian rhythm. In the nucleus accumbens, under both constant light or dark conditions, no changes were found in the circadian rhythm in any of the neurotransmitters and metabolites studied. These findings show that in the striatum, dopamine but not glutamate and GABA, seem to be influenced by light. In the nucleus accumbens, however, the three neurotransmitters had a circadian rhythm, which was independent of light.

Perfusion of melatonin into the prefrontal cortex disrupts the circadian rhythm of acetylcholine but not of locomotor activity.

Extracellular concentrations of acetylcholine (ACh) in the prefrontal cortex displayed a circadian rhythm, with a maximum increase in the dark phase of the light:dark cycle. The increase in ACh related well to the circadian rhythm of the same rats in which a maximal increase of locomotor activity in the dark phase also was observed. Local perfusion of melatonin (200-500 microm), in a dose-dependent manner, disrupted the ACh rhythm in the prefrontal cortex but did not affect the circadian rhythm of locomotor activity. It is suggested that the change in the cholinergic transmission during a circadian period in the prefrontal cortex may be under the control of the biological clock through the action of melatonin; however, the prefrontal cortical ACh cycle seems not to be related to the regulation of locomotor activity.