Summary
We report findings in five patients who presented with venous thrombosis and thrombocytopenia 7 to 10 days after receiving the first dose of the ChAdOx1 nCoV-19 adenoviral vector vaccine against coronavirus disease 2019 (Covid-19). The patients were health care workers who were 32 to 54 years of age. All the patients had high levels of antibodies to platelet factor 4–polyanion complexes; however, they had had no previous exposure to heparin. Because the five cases occurred in a population of more than 130,000 vaccinated persons, we propose that they represent a rare vaccine-related variant of spontaneous heparin-induced thrombocytopenia that we refer to as vaccine-induced immune thrombotic thrombocytopenia.
The aim of this study was to examine a possible association between smoking, alcohol and headache in a large population-based cross-sectional study. A total of 51,383 subjects completed a headache questionnaire and constituted the 'Head-HUNT' Study. Questionnaire-based information on smoking was available in 95% and on alcohol in 89% of the individuals. Associations were assessed in multivariate analyses, estimating prevalence odds ratios (ORs) with 95% confidence intervals (CI). Prevalence rates for headache were higher amongst smokers compared with never smokers, most evident for those under 40 years smoking more than 10 cigarettes per day (OR 1.5, 95% CI 1.3-1.6). Passive smoking was also associated with higher headache prevalence. For alcohol use, there was a tendency of decreasing prevalence of migraine with increasing amounts of alcohol consumption compared with alcohol abstinence. Only with regard to symptoms indicating alcohol overuse, a positive association with frequent headache was found. The association between headache and smoking found in the present study raises questions about a causal relationship, e.g. that smoking causes headache or that it allays stress induced by headache. The observed negative association between migraine and alcohol consumption is probably explained by the headache precipitating properties of alcohol.
The Nord-Trøndelag Health Study (HUNT 3) performed in 2006–2008 is a replication of the cross-sectional survey from 1995 to 1997 (HUNT 2). The aim of the present study was to assess the sensitivity and specificity of questionnaire-based headache diagnoses using a personal interview by a neurologist as a gold standard. For the questionnaire-based status as headache sufferer, a sensitivity of 88%, a specificity of 86%, and a kappa statistic of 0.70 were found. Chronic headache, chronic tension-type headache (TTH), and medication overuse headache (MOH) were diagnosed with a specificity of ≥99%, and a kappa statistic of ≥0.73. Lower figures were found for the diagnoses of migraine and TTH. For individuals with headache ≥1 day per month, a sensitivity of 58% (migraine) and 96% (TTH), a specificity of 91 and 69%, and a kappa statistic of 0.54 and 0.44 were found, respectively. The specificity for migraine with aura was 95%. In conclusion, the HUNT 3-questionnaire is a valid tool for identifying headache sufferers, and diagnosing patients with chronic headache, including chronic TTH and MOH. The more moderate sensitivity for migraine and TTH makes the questionnaire-based diagnoses of migraine and TTH suboptimal for determining the prevalence. However, the high specificity of the questionnaire-based diagnosis of migraine, in particular for migraine with aura, makes the questionnaire a valid tool for diagnosing patients with migraine for genetic studies.
This large questionnaire-based study confirms that migraine and other headaches are associated with respiratory and allergic disorders. The magnitude of the association between headache and asthma, hay fever, and chronic bronchitis tended to be in the same order. Headache frequency seems to have a greater impact on the association with respiratory or allergic conditions than headache diagnoses. Whether it is a causal relationship is uncertain, but the results underline the importance of considering comorbid disorders among patients with frequent headache.
Both MA, MO and non-migrainous headache are associated with an unfavourable cardiovascular risk profile, but different mechanisms seem to underlie the elevated risk in MA than in the other headache types.
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