Diagnosis and Treatment of Cerebral Salt Wasting Syndrome With Cryptococcal Meningitis in HIV Patient

Abstract

Hyponatremia is one of the most common electrolyte imbalances in HIV patients. The differential diagnosis may include hypovolemic hyponatremia, syndrome of inappropriate antidiuretic hormone secretion (SIADH), and adrenal insufficiency. Here, we describe a case of hyponatremia secondary to cerebral salt wasting syndrome (CSWS) in an HIV patient with cryptococcal meningitis. A 52-year-old man with a history of diabetes and HIV was admitted for headache and found to have cryptococcal meningitis. He was also found to have asymptomatic hyponatremia. He had signs of hypovolemia, such as orthostatic hypotension, dry mucosa, decreased skin turgor, hemoconcentration, contraction alkalosis, and high BUN/Cr ratio. The laboratory findings revealed sodium of 125 mmol/L, potassium of 5.5 mmol/L, urine osmolality of 522 mOsm/kg, urine sodium of 162 mmol/L, and urine chloride of 162 mmol/L. We started normal saline for hypovolemia, each 1 L prior and after amphotericin therapy. However, hypovolemia did not improve significantly despite IV fluid. Cosyntropin stimulation test was negative, and renin level was 0.25 ng·mL·h, with the aldosterone level of <1 ng/dL, the serum brain natriuretic peptide of 15 pg/mL, and serum uric acid of 2.8 mg/dL. The diagnosis of CSWS was suspected, fludrocortisone was tried, and hypovolemia and hyponatremia improved. Cryptococcal meningitis in HIV patients can present with CSWS, and the distinction between CSWS and SIADH is important because the treatment for CSWS is different than that of SIADH. Both share a similar clinical picture except that CSWS presents with constant hypovolemia despite volume replacement. Salt tablets, normal saline, or fludrocortisone can be used for treatment.

Hyponatremia as the Initial Presentation of Cryptococcal Meningitis After Liver Transplantation

“…Up to our knowledge, only one case of SIADH secondary to cryptococcal meningitis was reported in the literature; the patient was receiving immunosuppressive treatment (prednisone and azathioprine) for ulcerative colitis ( 2 ). Cerebral salt wasting syndrome (CSWS) is another condition, which may present similarly to SIADH in a patient with cryptococcal meningitis, but usually the patient is hypovolemic ( 10 ). Laboratory findings such as high urine osmolality, high urine sodium concentration, low serum uric acid, and low serum osmolality are found in both conditions ( 10 ).…”

“…Cerebral salt wasting syndrome (CSWS) is another condition, which may present similarly to SIADH in a patient with cryptococcal meningitis, but usually the patient is hypovolemic ( 10 ). Laboratory findings such as high urine osmolality, high urine sodium concentration, low serum uric acid, and low serum osmolality are found in both conditions ( 10 ). SIADH is a result of increased levels of antidiuretic hormone, which leads to water retention and hyponatremia.…”

“…CSWS involves salt loss from the kidneys due to decreased reabsorption of sodium. Moreover, treatment of CSWS varies from that of SIADH ( 10 ). Before managing SIADH, duration of hyponatremia and the underlying disorder must be identified.…”

Association of Hyponatremia on Mortality in Cryptococcal Meningitis: A Prospective Cohort

“…Hyponatremia in CNS cryptococcosis, however, has not been well described. Published literature on the topic of hyponatremia in cryptococcal meningitis (CM) is limited to a few case reports in which cases of both cerebral salt wasting and SIADH are described [ 6–9 ]. In the published literature, sodium levels and the general condition of patients with clinical and laboratory findings consistent with cerebral salt wasting improved with administration of isotonic saline and fludrocortisone, whereas those with SIADH improved with treatment of CM.…”