Hyponatraemia in stroke patients: A single-centre prospective cohort study.

Cerebral salt wasting syndrome (CSWS) and syndrome of inappropriate anti diuretic hormone secretion (SIADH) are the most common aetiological factors for developing hyponatremia following stroke. The differentiation of these two entities is crucial as the treatment options are completely different. The aim of this study is to determine the incidence of aetiologies of hyponatremia and compare demographic, clinical, imaging and laboratory parameters in each groupTwo hundred and forty-six patients with confirmed strokes were prospectively observed throughout the hospital stay in a tertiary referral center in Sri Lanka to identify the possible predictors of CSWS. Hyponatremia was defined as a serum Na+ level less than 131mmo/l. Serum osmolality, urine osmolality, urinary Na+, serum cortisol and thyroid function tests were performed on all the hyponatremic patients. The CSWS and SIADH were differentiated based on physical examination findings and laboratory parameters.The incidence of hyponatremia in our study population was 19.1% (95% Confidence interval, 14.39-24.58). The majority of patients (24, 51%) were attributed to CSWS. SIADH group comprised of 17 (36.2%) patients and 6 (12.7%) patients had other undetermined causes.The incidence of CSWS is higher than the incidence of SIADH among stroke patients in our setting.