SESSION TITLE: Wednesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Increased attenuation of basal cisterns and subarachnoid space on the computed tomography (CT) scan is the typical finding of subarachnoid hemorrhage (SAH). Several causes have been known to mimic the radiological findings of SAH, including pyogenic meningitis, leptomeningeal carcinomatosis, or recently administered intrathecal or intravenous contrast. We report a case of persistent headache whose CT scan had the typical finding of SAH and hydrocephalus but was diagnosed as disseminated coccidiomycosis. CASE PRESENTATION: A 53-year-old African American male with unknown medical history who live in TX. He is an operator for an oil company and has to travel around the States. He presented with a 1-month history of persistent headaches, night sweat, and weight loss. His boss noticed that he had been having episodes of confusion for the past 2 weeks and requested him to be evaluated. Upon arrival at the ED, he was confused without significant neurological abnormality on the exam. Vital signs were unremarkable. CT head without contrast revealed hydrocephalus, with areas of increased attenuation noted within the bilateral sylvian fissures, mid brain, and cerebral peduncle consistent with SAH. CT angiography did not show cerebral aneurysms. Magnetic Resonance imaging (MRI) revealed diffuse leptomeningeal enhancement, hydrocephalus, and papilledema. Lumbar puncture revealed colorless cerebrospinal fluid (CSF) with remarkable for white cell count of 250 cells/mm3 (59% lymphocytes), protein of 360 mg/dL, glucose of 36 mg/dL, and elevated open pressure of 45 cm of water. Serum and CSF Coccidioides complement fixing antibody titer were elevated, 1:32 and 1:2048 respectively. CSF culture grew Coccidioides immitis/posadasii. CT chest showed ground glass lesions on the right upper lobe. Bronchoalveolar lavage grew Coccidioides sp.. Ventriculoperitoneal shunt was placed and fluconazole was initiated. Neurological status improved and he was discharged a week later. DISCUSSION: Coccidioides spp. typically cause asymptomatic or mild primary infection. Infection can disseminate and involve the central nervous system (CNS), skin, joints, and bones. Meningitis with hydrocephalus is the most common CNS presentation. Our case posed a diagnostic difficulty because of the SAH appearance and hydrocephalus on the initial CT scan. Based on the imaging findings alone, the most likely diagnosis was felt to be SAH with complicated hydrocephalus. However, there was a disparity between the radiologic findings and the symptoms onset. This was reinforced by the MRI and lumbar punctures, which gave the definite diagnosis of disseminated coccidiomycosis with meningitis. CONCLUSIONS: We suggest that CNS infection should be considered if the clinical presentation is atypical or not in keeping with the radiological findings of SAH. Reference #1: Al-Yamany M, et al. Pseudo-subarachnoid hemorrhage: a rare neuroimaging pitfall. Can J Neurol Sci 1999;26: 57–59 Reference #2: Galgiani JN, Ampel NM, Blair JE, Catanzaro A, Geertsma F, Hoover SE, et al. 2016 Infectious Diseases Society of America (IDSA) Clinical Practice Guideline for the Treatment of Coccidioidomycosis. Clin Infect Dis. 2016;63(6):e112-46. DISCLOSURES: No relevant relationships by Cinthya Carrasco Barcenas, source=Web Response No relevant relationships by John Makram, source=Web Response No relevant relationships by Haneen Mallah, source=Web Response No relevant relationships by David Sotello Aviles, source=Web Response No relevant relationships by Myrian Vinan Vega, source=Web Response No relevant relationships by Wasawat Vutthikraivit, source=Web Response