B48-06 Cerebral Edema Following Intrathecal Myelography: A Rare Complication

Abstract Introduction Myelography with intrathecal contrast is infrequently performed in the modern era given MRI availability, but it remains useful in patients with contraindications or diagnostic uncertainty. While complications such as headache, nausea, and contrast reactions are well documented, cerebral edema following intrathecal contrast is exceedingly rare. We present a case of suspected contrast-associated cerebral edema after CT myelography. Case Presentation A 74-year-old male with a history of coronary artery disease, heart block with ICD placement, chronic kidney disease, diabetes mellitus, and hypertension presented with worsening low back pain and progressive bilateral lower extremity weakness. CT myelography with 12 mL of iohexol (Omnipaque 180) demonstrated severe lumbar canal stenosis at L2-L3. The patient underwent repeat myelography with additional intrathecal contrast to better visualize the lesion. Within days, he developed acute kidney injury requiring CRRT and subsequently manifested altered mental status. Brain CT revealed subtle diffuse cerebral edema, thought to be secondary to contrast neurotoxicity in the setting of impaired renal clearance and repeat intrathecal dosing. No evidence of infection or vascular insult was found. With supportive care and renal replacement therapy, the patient’s mentation improved, and follow-up neuroimaging showed resolution of cerebral edema. Discussion Neurotoxicity from intrathecal iodinated contrast is rarely reported, particularly manifesting as cerebral edema. Risk factors in this case included renal dysfunction, cumulative intrathecal contrast dose, and systemic comorbidities. The pathophysiology is thought to involve direct disruption of the blood-brain barrier and impaired clearance, leading to cerebral swelling. Recognition of this complication is crucial as early supportive care, especially renal replacement therapy, may aid recovery. This case highlights the importance of careful patient selection, minimizing repeat intrathecal dosing, and monitoring high-risk patients for neurologic deterioration. Conclusion We report a rare case of cerebral edema following CT myelography, likely secondary to intrathecal contrast neurotoxicity in a patient with CKD and AKI. Clinicians should maintain vigilance for neurocognitive changes post-procedure, particularly in high-risk populations. This abstract is funded by: None