Injections of Intravenous Contrast for Computerized Tomography Scans Precipitate Migraines in Hereditary Hemorrhagic Telangiectasia Subjects at Risk of Paradoxical Emboli: Implications for Right-to-Left Shunt Risks.

OBJECTIVE: To evaluate if injection of intravenous particles may provoke migraines in subjects with right-to-left shunts due to pulmonary arteriovenous malformations (AVMs). BACKGROUND: Migraine headaches commonly affect people with hereditary hemorrhagic telangiectasia (HHT), especially those with pulmonary AVMs that provide right-to-left shunts. In our clinical practice, patients occasionally reported acute precipitation of migraine headaches following injection of technetium-labeled albumin macroaggregates for nuclear medicine scans. METHODS: Self-reported migraine features and exacerbations were examined in HHT subjects with and without pulmonary AVMs, for a series of noninvasive and invasive investigations, using an unbiased online survey. RESULTS: One hundred and sixty-six subjects were classified as having both HHT and migraines. HHT subjects with migraines were more likely to have pulmonary AVMs (P < .0001). HHT subjects with pulmonary AVMs were more likely to report photophobia (P = .010), "flashes of light" (P = .011), or transient visual loss (P = .040). Pulse oximetry, x-rays, ultrasound, and computerized tomography (CT) scans without intravenous contrast medium rarely, if ever, provoked migraines, but unenhanced magnetic resonance imaging (MRI) was reported to exacerbate migraines by 14/124 (11.2%) subjects. One hundred and fourteen subjects had both enhanced and unenhanced CT examinations: studies with contrast media were more commonly reported to start (9/114 [7.8%]), and/or worsen migraines (18/114 [15.7%]), compared to those undertaken without contrast medium (P < .01), or after simple blood tests (P < .05). Additionally, migraine exacerbation was reported by 9/90 (10%) after contrast echocardiography, 2/44 (4.5%) after nuclear medicine scans, and 10/154 (6.5%) after blood tests. CONCLUSIONS: HHT subjects frequently report migraine exacerbation following blood tests, contrast echocardiograms, MRI imaging, and CT studies performed with intravenous contrast medium. Since air emboli are recognized to complicate intravenous injections, particularly those given by a pressurized pump during contrast enhanced CT, future studies should re-evaluate whether particulate emboli provoke migraines.

Relationships between epistaxis, migraines, and triggers in hereditary hemorrhagic telangiectasia.

OBJECTIVES/HYPOTHESIS: To identify whether relationships exist between epistaxis and migraines in hereditary hemorrhagic telangiectasia (HHT), to potentially provide further preventative and therapeutic options for the debilitating nosebleeds that are often very difficult to manage in clinical practice. STUDY DESIGN: Study participants were recruited from a UK specialist service, and online following advertisement by the HHT Foundation International. They completed a nonbiased questionnaire in which paired questions on nosebleeds and migraines were separated by at least 17 other questions. METHODS: Migraines were defined as headaches with associated autonomic and/or neurological features. The reported frequencies and precipitants of epistaxis and migraines were compared using numerical scales applied equally for each condition. RESULTS: The 220 HHT-affected respondents reported frequent nosebleeds, 153 (69.5%) used iron tablets, and 39 (17.7%) had received at least 10 blood transfusions. Migraines displaying typical features were reported by 51 (23.2%), and were more common with pulmonary or cerebral arteriovenous malformations. Thirty of 51 (58.8%) migraine sufferers reported that nosebleeds occurred at the same time as their migraines. More frequent migraines were reported by patients with more frequent nosebleeds (r2=15%, P=.007), or transfusions (r2=16.9%, P=.004). In menstrual, lifestyle, and dietary analyses, consistency was observed between factors having no effect, and those provoking both nosebleeds and migraines in multiple patients (premenses; activity; lack of sleep; stress; caffeine, cheese, alcohol, and chocolate). CONCLUSIONS: We demonstrate an unexpected and provocative association between nosebleeds and migraines in HHT patients. Evaluation of whether antimigraine approaches limit HHT nosebleeds may be appropriate. LEVEL OF EVIDENCE: 4.