Chronic open-angle glaucoma and ocular hypertension. An epidemiological study.
(65/1420)
An epidermiological study of patients with chronic simple glaucoma or ocular hypertension suggests that the diagnosis of glaucoma is associated with a positive family history, acute blood loss, and diabetes mellitus. There was no association with other vascular disease or with smoking. Ocular hypertension was related to smoking habits but not to family history. The relationship of these variables to ocular hypertension/glaucoma status is discussed. (+info)
Epidemiology of headache in Hong Kong primary-level schoolchildren: questionnaire study.
(66/1420)
OBJECTIVE: To collect and analyse epidemiological data on childhood headache in the Hong Kong community. DESIGN: Questionnaire study. SETTING: Three primary schools, Hong Kong. PARTICIPANTS: Two thousand, one hundred and twenty pupils from 2156 replied to the questionnaire survey. One hundred and twenty-four pupils who were identified to have suspected recurrent headache were invited to a follow-up medical consultation. MAIN OUTCOME MEASURES: Age-groups and prevalence of tension-type and migraine headache, using the diagnostic criteria of the International Headache Society. RESULTS: The overall prevalence of headache in the 2120 respondents was 2.8%. The prevalence of tension-type headache, migraine, probable migraine, and unclassified headache were 1.2%, 0.5%, 0.7%, and 0.5%, respectively. The age-specific prevalence of headache from the age of 6 to 13 years showed a steadily increasing trend from childhood to the early teens. CONCLUSION: Headache is a common complaint for children, although it may be underrecognised. Further study will be beneficial for providing better management of headache in this population. (+info)
An extract of Petasites hybridus is effective in the prophylaxis of migraine.
(67/1420)
OBJECTIVE: Migraine is still an unsolved problem. This clinical trial investigates the efficacy and tolerance of Petasites hybridus in the prophylaxis of migraine. METHODS: A randomized, group-parallel, placebo-controlled, double-blind clinical study was carried out with a special CO2 extract from the rhizome of Petasites hybridus. Following a four-week run-in phase, 60 patients received either the special Petasites hybridus extract Petadolex or placebo at a dosage of two capsules (each capsule contains 25 mg) twice daily over 12 weeks. Outcome variables included the frequency, intensity and duration of migraine attacks as well as any accompanying symptoms. RESULTS: The frequency of migraine attacks decreased by a maximum of 60 percent compared to the baseline. This reduction in migraine attacks with Petadolex was significant (p < 0.05) compared to placebo. No adverse events were reported. Petasites was exceptionally well tolerated. CONCLUSIONS: The results suggest that migraine patients can benefit from prophylactic treatment with this special extract. The combination of high efficacy and excellent tolerance emphasizes the particular value that Petasites hybridus has for the prophylactic treatment of migraine. (+info)
Effect of MAO-A inhibition on the pharmacokinetics of almotriptan, an antimigraine agent in humans.
(68/1420)
AIMS: To assess the effect of a reversible MAO-A inhibitor, moclobemide, on the single-dose pharmacokinetics of almotriptan and assess the clinical consequences of any interaction. METHODS: Twelve healthy volunteers received the following treatments in a randomized, open-label, two-way crossover design (with a 1 week washout between treatments): (A) one 150 mg moclobemide tablet every 12 h for 8 days and one 12.5 mg almotriptan tablet on the morning of day 8; and (B) one 12.5 mg almotriptan tablet on day 8. Plasma almotriptan was quantified by h.p.l.c.-MS-MS, while urinary concentrations were measured by h.p.l.c.-u.v. Vital signs, ECGs, and adverse events were evaluated after almotriptan administration. Treatment effects on pharmacokinetics and vital signs were assessed by analysis of variance. RESULTS: Mean almotriptan AUC was higher (483 +/- 99.9 vs 352 +/- 75.4 ng ml-1 h, P = 0.0001) and oral clearance was lower (26.6 +/- 4.00 vs 36.6 +/- 5.89 l h-1, P = 0.0001) when almotriptan was administered with moclobemide. Mean half-life was longer (4.22 +/- 0.78 vs 3.41 +/- 0.45 h, P = 0.0002) after coadministration with moclobemide. Renal clearance of almotriptan was unaffected by moclobemide. No serious adverse events occurred and no clinically significant vital sign changes were observed. CONCLUSIONS: Moclobemide increased plasma concentrations of almotriptan on average by 37%, but the combined administration of these two compounds was well tolerated. The degree of interaction was much less than that seen previously for sumatriptan or zolmitriptan given with moclobemide. (+info)
Hereditary vascular retinopathy, cerebroretinal vasculopathy, and hereditary endotheliopathy with retinopathy, nephropathy, and stroke map to a single locus on chromosome 3p21.1-p21.3.
(69/1420)
We performed a genomewide search for linkage in an extended Dutch family with hereditary vascular retinopathy associated with migraine and Raynaud phenomenon. Patients with vascular retinopathy are characterized by microangiopathy of the retina, accompanied by microaneurysms and telangiectatic capillaries. The genome search, using a high throughput capillary sequencer, revealed significant evidence of linkage to chromosome 3p21.1-p21.3 (maximum pairwise LOD score 5.25, with D3S1578). Testing of two additional families that had a similar phenotype, cerebroretinal vasculopathy, and hereditary endotheliopathy with retinopathy, nephropathy, and stroke, revealed linkage to the same chromosomal region (combined maximum LOD score 6.30, with D3S1588). Haplotype analysis of all three families defined a 3-cM candidate region between D3S1578 and D3S3564. Our study shows that three autosomal dominant vasculopathy syndromes with prominent cerebroretinal manifestations map to the same 3-cM interval on 3p21, suggesting a common locus. (+info)
The anti-migraine 5-HT(1B/1D) agonist rizatriptan inhibits neurogenic dural vasodilation in anaesthetized guinea-pigs.
(70/1420)
These studies investigated the pharmacology of neurogenic dural vasodilation in anaesthetized guinea-pigs. Following introduction of a closed cranial window the meningeal (dural) blood vessels were visualized using intravital microscopy and the diameter constantly measured using a video dimension analyser. Dural blood vessels were constricted with endothelin-1 (3 microg kg(-1), i.v.) prior to dilation of the dural blood vessels with calcitonin gene-related peptide (CGRP; 1 microg kg(-1), i.v.) or local electrical stimulation (up to 300 microA) of the dura mater. In guinea-pigs pre-treated with the CGRP receptor antagonist CGRP((8-37)) (0.3 mg kg(-1), i.v.) the dilator response to electrical stimulation was inhibited by 85% indicating an important role of CGRP in neurogenic dural vasodilation in this species. Neurogenic dural vasodilation was also blocked by the 5-HT(1B/1D) agonist rizatriptan (100 microg kg(-1)) with estimated plasma levels commensurate with concentrations required for anti-migraine efficacy in patients. Rizatriptan did not reverse the dural dilation evoked by CGRP indicating an action on presynaptic receptors located on trigeminal sensory fibres innervating dural blood vessels. In addition, neurogenic dural vasodilation was also blocked by the selective 5-HT(1D) agonist PNU-142633 (100 microg kg(-1)) but not by the 5-HT(1F) agonist LY334370 (3 mg kg(-1)) suggesting that rizatriptan blocks neurogenic vasodilation via an action on 5-HT(1D) receptors located on perivascular trigeminal nerves to inhibit CGRP release. This mechanism may underlie one of the anti-migraine actions of the triptan class exemplified by rizatriptan and suggests that the guinea-pig is an appropriate species in which to investigate the pharmacology of neurogenic dural vasodilation. (+info)
A neurohistochemical blueprint for pain-induced loss of appetite.
(71/1420)
A common complaint among pain patients is that they lose their appetite. These accounts are anecdotal, however, and the neural mechanism underlying pain-induced loss of appetite remains unknown. In this study, we documented the occurrence of appetite loss in patients under migraine attack and investigated the neuronal substrate of pain-induced anorexia in our animal model of intracranial pain. We found that loss of appetite during the migraine attack in humans coincided strongly with the onset and duration of the head pain in 32/39 cases, and that brief noxious stimulation of the dura in conscious rats produced a transient suppression of food intake. Mapping of neuronal activation in the rat showed that noxious dural stimulation induced a 3- to 4-fold increase in the number of Fos-positive neurons in medullary dorsal horn areas that process nociceptive signals (laminae I, V) and in parabrachial and hypothalamic neurons positioned to suppress feeding behavior. In the parabrachial area, activated neurons were localized in the superior-lateral subnucleus, and 40% of them expressed the mRNA encoding the anorectic neuropeptide cholecystokinin. In the hypothalamus, activated Fos-positive neurons were found in the dorsomedial area of the ventromedial nucleus, and 76% of them expressed the mRNA for cholecystokinin type-B receptor. Based on these findings, we suggest that at least one of several groups of hypothalamic neurons that normally inhibit appetite in response to metabolic cues is positioned to mediate the suppression of food intake by pain signals. (+info)
Prevalence of migraine.
(72/1420)
The prevalence of migraine in the general population has been calculated using a standard mailed questionnaire, which inquired about headache and the individual features of migraine, and which previously had been compared with a clinical diagnosis. In three separate epidemiological surveys the prevalence in the preceding year was found to be between 23 and 29% in women and between 15 and 20% in men. The prevalence declined with age in both men and women. These surveys show that migraine is much more prevalent than the frequently quoted figure of about 10% of the population which does not seem to be based on any particular survey. (+info)