2017 Resarch Forum

IM: C-7

Applicant & Principal Investigator: Ali Ammar MD

A case of syndrome of inappropriate antidiuretic hormone secretion (SIADH)induced by disseminated central nervous system (CNS) coccidioidomycosis Ali Ammar MD, Arash Heidari MD, Taylor Barrett MS III, Saman Ratnayake MD INTRODUCTION Coccidioidomycosis is a fungal pathogen that has a history of repeated infections primarily in Southwestern United States and Northern Mexico. Manifestations of coccidioidomycosis infections can range from pneumonia to organ and tissue dissemination. CNS coccidioidomycosis has been described multiple times in the past, but has never been associated with hyponatremia. PURPOSE To describe a case of SIADH induced by disseminated coccidioidomycosis. DISCUSSION We describe a case of a 19 year old female with coccidioidomycosis meningitis after four months of field work in central California. This patient presented to the emergency department with the complaint of an ongoing headaches and subjective fevers for 8 days. She reported associated nausea and vomiting since the onset of her headache. Vitals were within normal limits on admission. Labs: Lumbar puncture showing an elevated opening pressure of 55 cm of H2O and cytology showed a glucose of 17 with and elevated WBC of 2700 with pleocytosis. Gram stains of CSF were repeatedly negative. Serum coccidioidomycosis serology resulted as IgM weakly reactive suggesting acute disseminated coccidioidomycosis meningitis. Serum osmolality was found to be decreased at 252 and urine osmolality was 485 with urine sodium of 92, all of which were consistent with SIADH. Treatment: Patient was treated with fluid restriction and fluconazole 1000mg daily. Continued daily labs were ordered and patient showed persistent hyponatremia as low as 120. Therapeutic serial lumbar punctures were performed in an effort to reduce intracranial pressure until on day 4 when pressures returned to normal. Physical Exam: Positive nuchal rigidity and positive Brudzinki’s and Kernig’s signs.

After two weeks of this therapy, the patient showed significant clinical improvement and sodium normalized.

There have been no cases of SIADH secondary to CNS coccidioidomycosis described in current literature.

CONCLUSION In patients with CNS coccidioidomycosis who also present with unexplained SIADH, CNS coccidioidomycosis should be considered in the differential diagnoses as a potential cause of SIADH.