A 32‐year‐old man with chronic low back pain presented with tonic–clonic seizures and altered mental status approximately 12 hours after he underwent an outpatient CT myelogram with Iopamidol contrast. Headache, nausea and vomiting preceded the seizure. His temperature was 37.9°C; he had nuchal rigidity and was unresponsive but able to move all extremities. Serum white cell count was 22,600 cells/mL with 74% neutrophils. Lumbar puncture revealed cloudy fluid with 17,925 white blood cells with 93% polymorphonuclear cells, a glucose level of 0.333 mmol/L (6 mg/dL) and protein level of 12.38 gm/L He was treated with vancomycin, ceftazidime, and dexamethasone. About 48 hours later, he was afebrile, and his neurological status had improved. CSF and blood cultures were negative. Procalcitonin level at admission was 5.77 ng/mL and a repeat level on day 4 was 1.88 ng/mL. Despite negative cultures, the patient completed a 14‐day course of antibiotics. In subsequent follow‐up, he had no residual deficits. However, he did develop acute kidney injury requiring readmission. Interstitial nephritis related to antibiotics was felt to be the cause of the acute kidney injury.
This case highlights the difficulty in distinguishing postprocedural bacterial meningitis from chemical meningitis. Both are exceedingly rare. In both conditions, patients generally present within 24 hours of the myelogram with fever, headaches, nausea, mental status changes, leukocytosis, CSF neutrophilic pleocytosis, hypoglycorrhachia, and elevated protein levels. In chemical meningitis, CSF cultures are negative. In the few existing case reports, most patients with presumed chemical meningitis recover within a few days without sequelae. The neurotoxicity of contrast agents has been linked to their osmolarity and lipid solubility. Bender et al.1 theorized that procalcitonin levels might be able to discriminate between bacterial and chemical meningitis. Comparing 7 patients with proven bacterial meningitis with 1 patient with aseptic, chemical meningitis, they found that only procalcitonin levels remained in the relatively normal range in the patient with chemical meningitis. Other inflammatory markers overlapped. In our case, the profundity of CSF abnormalities and the markedly elevated procalcitonin levels likely contributed to the recommendation for antibiotics by infectious disease specialists despite sterile cultures. Ultimately, the patient may have been harmed by unnecessary treatment.
Hospitalists should consider chemical meningitis in the differential diagnosis of postprocedure meningitis. There is inadequate data to establish the value of procalcitonin levels in distinguishing chemical from bacterial meningitis.
1. Andreas Bender et al. Severe symptomatic aseptic chemical meningitis following myelography. Neurology. 2004:63:1311–1313 To cite this abstract:
1. Andreas Bender et al. Severe symptomatic aseptic chemical meningitis following myelography. Neurology. 2004:63:1311–1313
To cite this abstract:Ilyas M, Basani S, Traub N. Meningitis After Diagnostic Myelography. Abstract published at Hospital Medicine 2013, May 16-19, National Harbor, Md. Abstract 333. Journal of Hospital Medicine. 2013; 8 (suppl 2). https://www.shmabstracts.com/abstract/meningitis-after-diagnostic-myelography/. Accessed April 4, 2020.