Iodinated contrast agents in myasthenia gravis

Abstract

Administration of intravenous iodinated contrast agents has been reported to cause increased weakness in myasthenia gravis (MG) patients. We reviewed the records of 136 patients with MG who had at least one radiologic procedure involving intravenously administered contrast media. Seven patients (5.1%) had contrast reactions, which compares with the 5% rate of contrast reactions in the general population. Five patients had either a subjective or objective increase in weakness that could be explained by reasons other than contrast administration. Only one patient was found to have increased respiratory muscle weakness, which could have been attributed to either contrast infusion or pulmonary embolism. We conclude that intravenous contrast agents are not contraindicated in MG, but extra care should be taken when they are given.

Effect of Intravenous Low-Osmolality Iodinated Contrast Media on Patients with Myasthenia Gravis

“…Although there are case reports and case series (9)(10)(11)(12)(13)(14) in the literature describing adverse outcomes (including myasthenic crisis) in patients with myasthenia gravis exposed to high-osmolality contrast material, the strength and validity of this relationship is even less clear for low-osmolality contrast material (15). None of the previous investigators compared their results with those in a control group of patients not exposed to contrast material, and most Table 2 Myasthenia Gravis-related Symptom Deterioration after Unenhanced and Contrast-enhanced CT Time to Deterioration and Symptoms Unenhanced CT (n = 155)* Contrast-enhanced CT (n = 112)* P Value † two of seven leading to unresponsiveness and/or death.…”

“…There have been a few case reports (9)(10)(11)(12)(13)(14) describing isolated examples of a myasthenic crisis that developed after exposure to intravenous high-osmolality iodinated contrast material. However, not only are these case reports anecdotal, they are also dated because Implication for Patient Care n Intravenous administration of low-osmolality contrast material should be considered among the list of medications known to exacerbate myasthenic symptoms, with an estimated risk of acute symptom deterioration of approximately 5%-6% above baseline (95% confidence interval: 0%, 12%).…”

“…We detected no difference in symptom frequency at 2-7 days or 8-45 days after CT, indicating that the association between intravenous low-osmolality contrast material and symptom progression is a relatively acute association. Acute symptom exacerbations after contrast-enhanced CT were usually respiratory and generally serious, with (9)(10)(11)(12)(13)(14) reported on patients receiving contrast media that are no longer used routinely for intravascular purposes. For example, one case report described a 52-year-old woman who developed an inability to swallow, hypersalivation, and diffuse muscle weakness necessitating intubation following the intravenous administration of meglumine iothalamate (9).…”

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“…11,12 Conversely, 1 study has shown that occurrence of a myasthenic crisis because of intravenous injection of contrast is controversial. 13 Most patients in the reported cases became apneic immediately after intravenous injection of contrast material. In our patient, no signs were observed immediately or shortly after administering the contrast injection.…”

Iodinated contrast agents in patients with myasthenia gravis: a retrospective cohort study

“…One systematic retrospective study on acute adverse events (within 24 h) associated with high-osmolality agents presented five patients with a subsequent exacerbation of their myasthenic weakness, although in each case, alternative explanations for the deterioration other than ICA administration were possible [14]. …”