Severe hyponatraemia in a quadriplegic.

A young quadriplegic patient developed convulsions and brain damage due to severe hyponatraemia. Potential causes of severe hyponatraemia in quadriplegics include excessive water intake (because of the low threshold for vasopressin release) and asymptomatic renal tract infection causing sodium loss. Mild hyponatraemia, occurring in up to 10% of quadriplegics, is due to a reset osmostat.