A patient with cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) confirmed by sural nerve biopsy.

recently it has become clear that hypona- traemia in the cerebral salt wasting syn- drome is accompanied by hypovolaemia.' 2We report a patient with cerebral salt wasting after aneurysmal subarachnoid haemorrhage who showed remarkable changes in urine production during surgery.A 46 year old woman was admitted with severe headache and vomiting.Physical examination was unremarkable.Brain CT showed a subarachnoid haemorrhage with blood in the suprasellar cisterns and the left Sylvian fissure.Two days later she devel- oped mild hyponatraemia and polyuria; salt and fluid loss were fully compensated by 0 9% NaCl infusion.On day 9 she was found unconscious with respiratory failure and bradycardia and CT disclosed a recur- rent subarachnoid haemorrhage in the left Sylvian fissure.The patient regained con- sciousness and she gradually recovered from a mild aphasia and right facial weakness.However, from day 12 onwards she again developed a progressive polyuria of up to 21 200 ml per day (on day 22) and a 24 hour renal sodium loss of 2630 mmol.The plasma sodium range was between 128 and 142 mmol/l, and the colloid osmotic pres- sure was between 18-7 and 24-0 mm Hg.Serum ADH concentrations were normal.