A Tick-borne Cause of Hyponatremia: SIADH Due to Lyme Meningitis

An 83-year-old woman was incidentally found to have hyponatremia (125 mmol/L) when undergoing inpatient colonoscopy because of unspecific gastrointestinal symptoms and weight loss; no pathology was found on endoscopy. Further biochemistry was in keeping with the syndrome of inappropriate antidiuretic hormone (SIADH) secretion (urinary sodium 66 mmol/L, urinary osmolality 321 mosmol/kg, low uric acid); adrenal and thyroid function as well as glucose were normal. The patient was remarkably fit for her age, she was a lifelong non-smoker and her only medication was candesartan for hypertension.
Source: The American Journal of Medicine - Category: General Medicine Authors: Tags: Clinical Communication to the Editor Source Type: research