Critical Assessment of Myelography Practices: A Call for Rational Guideline Revision

BACKGROUND AND PURPOSE: Patient preparation for myelography and postprocedural monitoring varies widely between practices, despite published guidelines. Our aim was to examine the current practice variations in discontinuing reportedly seizure threshold–lowering medications before myelography and to assess the reported incidence of postmyelographic seizures.

MATERIALS AND METHODS: An e-mail survey was sent to American Society of Neuroradiology members concerning the number of postmyelographic seizures experienced in the past 5 years, the presence of an institutional policy for discontinuing seizure threshold–lowering medications, and the type of myelographic contrast used. We compared the postmyelographic seizure frequency in the responses.

RESULTS: Of 700 survey responses, 57% reported that they do not discontinue seizure threshold–lowering medications before myelography. Most (97%) indicated never having a patient experience a seizure following myelography. The number of postmyelographic seizures between those who discontinue seizure threshold–lowering medications and those who do not was not statistically significant (OR = 2.13; 95% CI, 0.91–4.98; P = .08). Most (95%) reported using nonionic hypo-osmolar agents.

CONCLUSIONS: Survey results revealed widely variable practices for patient myelography preparation and postprocedural monitoring. We found no difference in reported seizures between those who discontinued seizure threshold–lowering medications and those who did not. In light of our findings, we propose that discontinuing reportedly seizure threshold–lowering medications is not warranted with the current nonionic water-soluble contrast agents and may be potentially harmful in some instances. This work supports revision of existing recommendations to withhold such medications before myelography.