Hypertrophic Pachymeningitis and the Syndrome of Inappropriate Antidiuretic Hormone Secretion: Coincidence or Cause?

Objective: To investigate a potential cause of the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Clinical Presentation and Intervention: A 70-year-old female patient had nausea and collapsed. Although euvolemic, pathological laboratory findings showed hyponatremia and hypoosmolality, and cerebral magnetic resonance imaging showed hypertrophic pachymeningitis. Secondary hypertrophic pachymeningitis was excluded. Other nonneurological reasons for SIADH were also excluded. Moderate fluid restriction restored an almost normal serum osmolality and sodium. Conclusion: This case of SIADH was conservatively treated with moderate fluid restriction that almost restored normal serum osmolality and sodium levels. (C) 2017 S. Karger AG, Basel