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

Abstract

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.

Keywords: computerized tomography (CT); contrast injection; hereditary hemorrhagic telangiectasia (HHT); magnetic resonance imaging (MRI); pulmonary arteriovenous malformations (PAVMs); right-to-left shunt.

© 2016 The Authors Headache published by Wiley Periodicals, Inc. on behalf of American Headache Society.

Figures

Figure 1

Reported associations with migraine headaches. Data from the 166 survey respondents meeting diagnostic criteria for HHT and migraines. The mean score, and standard error of the mean, are illustrated, noting individual responses ranged from never (0) to always (5). As reported elsewhere,5 almost half (70, 43.3%) described sometimes having an HHT nosebleed at the time of a migraine, and in 14 cases (8.4%) this occurred with most if not all migraines.

Figure 2

Reported exacerbation of migraines by investigations. Proportions of subjects reporting investigations exacerbated migraines, either starting or worsening a migraine. White bars: tests without injections, black bars, tests with injections, and stippled bar, venipuncture for blood tests. Mean and standard error of the mean displayed. Tests that never provoked migraines (pulse oximetry, x‐rays) are not displayed. The P values were calculated by Dunn's multiple comparison test after performing the Kruskal Wallis test across all 9 groups (overall P value < .0001).