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 hyper-trophic pachymeningitis was excluded. Other nonneurolog-ical 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