Diabetes Insipidus (Central)

Etiology

  • Decreased production of ADH from the hypothalamus
  • Results in inappropriately dilute urine

Risk Factors

  • Trauma or surgery affecting hypothalamic function
  • Infiltrative or inflammatory process affecting hypothalamus (e.g. Sarcoidosis, Ig4 related disease, hypophysitis)
  • Infection: encephalitis, meningitis
  • Cancer: craniopharyngioma, Langerhan's histiocystosis, lymphoma, mets to hypothalamus/pituitary stalk
  • Idiopathic; congenital

Symptoms

  • May have symptoms related to the primary process (e.g. head trauma, cancer)
  • From DI: persistent thirst, drinking large volumes of water, polyuria
  • Degree of DI varies with amount of ADH produced
  • If unable to drink enough free water to keep up with urine losses, may ultimately develop hypovolemia, confusion, hypernatremia

Physical Exam Findings

  • Tachycardia, hypotension if volume depleted
  • Altered mental status if significant hypernatremia

Tests