DR Medhat MRCP

DIABETES INSIPIDUS (DI)
- Polyuria ( > 50ml/kg/day [> 3L urine /day in 60 kg patient) ) due to either deficient or
inefficient ADH.
Aetiology of polyuria :
Deficient ADH Inefficient ADH inappropriate water intake
Cranial (hypothalamic)
DI
Nephrogenic DI
Dyspogenic DI
- Primary:
1. Idiopathic (+++). 1. Idiopathic. 1. 1ry (psychogenic)
2. Genetic : 2. Genetic : polydepsia.
- DIDMOAD - X-linked recessive
- Autosomal dominant. - Autosomal dom.
- Autosomal recessive - Autosomal recessive
- Secondary :
1. Trauma (head injury) 1. Tubulo-interstitial dis.
2. Tumour (craniopharyngioma) - Obstructive uropathy.
3. Pituitary surgery. - Pyelonephritis.
4. Histiocytosis X, TB, Sarcoid. - Sickle cell disease.
2. Hypercalcaemia.
3. Hypokalaemia
4. Drugs (lithium)
(Dmeclocycline)
DIDMOAD syndrome = DI + DM +Optic atrophy + Deafness
Also known as (Wolfarm`s syndrome)
Clinical picture :
1) Polyuria (> 3L /day) / polydipsia by day & night :
- If the patient can sleep deeply for continuous 8 hrs , diagnosis of cranial
& nephrogenic DI is unlikely.
2) Dehydration .
3) C/P of the cause e.g visual disturbance + headache if pituitary tumour
compressing the optic chiasma.