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Objective To study the influence of the migraine aura on the trigeminal nociception, we investigated the habituation of the nociceptive blink reflex (nBR) R2 responses in aura with migraine headache (AwMH) and comparatively in migraine without aura (MWoA) and healthy subjects (HS). Background A clear deficit of habituation in trigeminal nociceptive responses has been documented in MWoA; however, similar data in MWA are lacking. Methods Seventeen AwMH, 29 MWoA, and 30 HS were enrolled and a nonrandomized clinical neurophysiological study examining nBR habituation by clinical diagnosis was devised. We delivered a series of 26 electrical stimuli, at different stimulation frequencies (SF) (0.05, 0.1, 0.2, 0.3, 0.5, and 1 Hz), subsequently subdivided in five blocks of five responses for each SF. The mean area values of the second to the fifth block expressed as the percentage of the mean area value of the first block were taken as an index of habituation for each SF. Results A significant lower mean percentage decrease of the R2 area across all blocks was found at 1, 0.5, 0.3, and 0.2 Hz SF in MWoA and at 0.3 and 0.2 Hz SF in AwMH, when compared to HS. In the most representative fifth block of responses, we found in MWoA vs HS at 1 Hz, 57.0 ± 27.8 vs 30.6 ± 12.0; at 0.5 Hz, 54.8 ± 26.1 vs 32.51 ± 17.7; at 0.3 Hz, 44.7 ± 21.6 vs 27.6 ± 13.2; at 0.2 Hz, 61.3 ± 29.5 vs 32.6 ± 18.0, and in AwMH vs HS at 0.3 Hz, 52.7 ± 24.7 vs 27.6 ± 13.2; at 0.2 Hz, 69.3 ± 38.6 vs 32.6 ± 18.0 as mean ± SD of the R2 area percentage of the first block, respectively. Interestingly, AwMH subjects did not show differences in mean percentage decrease of the R2 area at 1 and 0.5 Hz SF when compared to HS. No differences between groups were found at 0.1 and 0.05 Hz SF. Conclusions We demonstrated in AwMH a deficit of habituation of the nBR R2 responses after repeated stimulations, although less pronounced than that observed in MWoA of comparable clinical severity. We hypothesize that AwMH and MWoA share some pathogenetic aspects, and also that migraine aura physiopathology may play a modulating role on the excitability of the nociceptive trigeminal pathways. [ABSTRACT FROM AUTHOR]

Objectives.- We investigated (1) a possible relationship between the functional activity of the endocannabinoid system and the facilitation of pain processing in migraineurs with medication-overuse headache, and (2) the effect of withdrawal treatment on both. Background.- The endocannabinoid system antinociception effect includes prevention of nociceptive pathways sensitization. The sensitization of the pain pathways has been demonstrated to be pivotal in the development and maintenance of chronic form of migraine, including medication-overuse headache. Methods.- We used the temporal summation threshold of the nociceptive withdrawal reflex to explore the spinal cord pain processing, and the platelet activity of the enzyme fatty acid amide hydrolase to detect the functional state of the endocannabinoid system in 27 medication-overuse headache subjects before and 10 and 60 days after a standard withdrawal treatment and compared results with those of 14 controls. Results.- A significantly reduced temporal summation threshold and increased related pain sensation was found in subjects before withdrawal treatment when compared with controls. A significant fatty acid amide hydrolase activity reduction coupled with a significant improvement (reduction) in facilitation of spinal cord pain processing (increase in temporal summation threshold and reduction in related pain sensation) was found in medication-overuse headache subjects at both 10 and 60 days after withdrawal treatment when compared with medication-overuse headache subjects before withdrawal treatment. Conclusions.- We demonstrated a marked facilitation in spinal cord pain processing in medication-overuse headache before withdrawal treatment when compared with controls. Furthermore, the acute reduction of the fatty acid amide hydrolase activity coupled with a reduction of the facilitation in pain processing immediately (10 days) after withdrawal treatment and its persistence 60 days after withdrawal treatment could represent the consequence of a mechanism devoted to acutely reduce the degradation of endocannabinoids and aimed to increase the activity of the endocannabinoid system that results in an antinociceptive effect. [ABSTRACT FROM AUTHOR]

Objective.- To study the prevalence of cephalalgia in male divers. Background.- Scuba divers work in stressing environments and have a high cerebrovascular risk, both conditions which are supposed to contribute to the genesis of cephalalgia. However, no study assessed expressly the prevalence of cephalalgia in divers, to date. Methods.- We enrolled 201 professional male scuba divers (41.0 ± 7.2 years) and controls (41.1 ± 7.2 years), and the risk ratio and its corresponding 95% confidence of suffering from cephalalgia was calculated. Results.- We found that 16% of divers and 22% of matched controls were affected by cephalalgia ( P > .05), accounting for a risk ratio of 0.71 (95% CI 0.47-1.07). Divers reported fewer attacks per month (1.8 ± 0.7, n = 32) with regard to controls (2.5 ± 1.8, n = 45) ( P = .02), but no differences concerning age at onset and severity were detected ( P > .05). Divers suffered from migraine, migraine with aura and tension headache as much as controls. Conclusion.- Scuba diving, an intense physical activity characterized by cerebral micro-vascular distress, is not associated with cephalalgia, as a whole, or migraine, tension headache or migraine with aura, more commonly than in a matched, non-diving, population. A longitudinal study may disclose if diving may act as a protective factor in the occurrence of crises of cephalalgia. ( Headache 2012;52:385-392) [ABSTRACT FROM AUTHOR]

Objective.—To evaluate trigemino-cervical-spinal reflexes (TCSRs) in a group of migraine patients during the pain-free period. Background.—TCRSs are part of a complex nocifensive response involving the cervical and the upper limb muscles, and are modulated by supraspinal inhibitory pathways; it may, thus, be possible to use TCRSs to explore the trigeminal system in migraineurs. Methods.—A total of 43 migraine patients without aura (MWoA, 32 patients) or with typical aura (MWA, 11 patients) and 30 age- and sex-matched healthy subjects took part in the study. TCRSs were obtained by stimulating the supraorbital nerve and recorded from the semispinalis capitis muscle and the biceps brachii. The latency (L, msec), area (A, mVms) and recovery cycle of the reflexes were recorded. The effects of heterotopic painful stimulation on the neurophysiological parameters were studied by a validated cold pressor test (CPT). Results.—No significant changes were found between either migraine patients and controls or MWoA and MWA patients in the mean values in the L and A of TCRSs ( t-test, P > .05). The recovery curve of the trigemino-cervical reflexes (TCRs) was significantly faster in migraine patients than in controls, while no differences were found in the trigemino-spinal reflexes (TSRs) ( t-test, P < .01). Activation of the diffuse inhibitory controls through the CPT induced a significant reduction in the TCRs and TSRs area in both migraine patients and controls (paired t-test, P < .01), though the extent of this reduction did not differ significantly between migraineurs and controls ( t-test, P > .05). Comments.—Our data suggest that the pain-free period in migraine patients is characterized by a hyperexcitability of the trigeminal pathways and of their anatomical and functional connections with the upper cervical cord neurons, and that this abnormal hyperexcitability does not appear to be due to a lack of a supraspinal inhibitory modulation. ( Headache 2005;45:1061-1068) [ABSTRACT FROM AUTHOR]