Spinal Coccidioidomycosis: MR Imaging Findings in 41 Patients

Abstract

BACKGROUND AND PURPOSE: Coccidioides immitis is a dimorphic fungus endemic to the Southwest United States and Mexico, and at our institution, it is a relatively common pathogen presenting with a broad spectrum of associated spine diseases. We describe the various spinal manifestations resulting from coccidioidal infection and provide MR imaging examples from 41 pathologically proved cases. MATERIALS AND METHODS: Retrospective electronic medical record and PACS searches were performed. Patients found to have both MR imaging findings positive for infection and confirmative biopsy and/or CSF studies were included. Abnormal MR imaging findings were identified, categorized, and quantified. Patient demographics and associated intracranial involvement if present were also recorded. RESULTS: Forty-one patients were included. Positive findings were categorized as leptomeningeal enhancement (26 patients, 63%), arachnoiditis (22 patients, 54%), osteomyelitis-discitis (14 patients, 34%), cord edema (11 patients, 27%), and true syrinx (3 patients, 7%). Thirty patients had documented brain involvement (73%), most commonly in the form of basilar meningitis. Four patients were positive for HIV (10%). Fifteen patients had pulmonary manifestations at presentation (37%). CONCLUSIONS: C immitis results in various spinal manifestations, most commonly leptomeningeal enhancement and arachnoiditis/ adhesive disease followed by osteomyelitis, which may resemble tuberculous or pyogenic infection on MR imaging. ABBREVIATION: T1ϩC ϭ T1-weighted images with contrast Coccidioides immitis is a dimorphic fungus well-known to be endemic to the Southwest United States and Mexico. 1,2 At our institution, we experience C immitis as a relatively common pathogen, presenting with variable pulmonary, intracranial, and spinal diseases regardless of immune status. The spectrum of spine disease reported in the literature is extensive, with involvement of the leptomeninges, epidural/paraspinal space, vertebral bodies both with and without disc involvement, and, rarely, the spinal cord. Although previous case reports and articles have discussed the imaging appearance of spinal coccidioidomycosis, to our knowledge, there has not been a comprehensive review of both intrathecal and vertebral/paraspinal involvement of this magnitude. 3-9 We describe the spinal MR imaging findings from 41 patients with pathologically proved Coccidioides infection.

Infectious Myelitis

“…Fungal myelitis is a rare manifestation of invasive fungal diseases. With the exception of coccidioidomycosis, 74 this is usually seen in immunocompromised individuals.…”

“…75 However, involvement of the spinal cord itself is a rarer occurrence. 74,[76][77][78] In a case series of 23 patients with coccidioidal meningitis, seven had intramedullary T2 hyperintense signal abnormality on MRI consistent with myelitis. Of note, four of these developed while undergoing treatment for CNS infection.…”

Fungal Infections of the Central Nervous System

“…Myelopathy most commonly results from secondary spinal cord damage in the context of epidural abscess formation, granulomas of the meninges, and bony destruction of the spine. 156,157 Fungi to consider in the context of myelopathy include aspergillosis, cryptococcus, candida, blastomyces, and coccidioidomycosis species. 77 Spread of infection frequently leads to associated paraspinal abscesses.…”

“…In one case series of 41 Coccidioidomycosis spine cases, there was associated leptomeningeal enhancement in 63%, arachnoiditis in 54%, osteomyelitis-discitis in 34%, cord edema in 27%, and syrinx in three patients. 156 Seventy-three percent had associated brain involvement, most commonly a basilar meningitis. In general, fungal myelopathies often require combined medical and surgical management, with a high likelihood of infection recurrence despite aggressive measures.…”

“…Here we highlight spinal involvement of exserohilum rostratum during the fungal CNS infection outbreak associated with contaminated steroid injections during 2012 to 2013. 156,157 Exserohilum Rostratum Infections During the 2012 to 2013 Fungal Meningitis Outbreak Seven hundred and fifty-one cases of CNS fungal infection, including 325 spinal and paraspinal infections, 151 meningitis, and spinal/paraspinal infections, were reported during the 2012 to 2013 U.S. fungal meningitis outbreak associated with steroid injections. 158 Many patients were found to have an insidious onset of spinal or paraspinal infection at the injection site, with symptoms delayed for weeks to months after exposure, often with subtle or absent clinical findings.…”