The hyponatraemic hypertensive syndrome in a 2-year-old child with behavioural symptoms.

<bold>Unlabelled: </bold>In this case report we present a 2-year-old girl with the classical signs of the hyponatraemic hypertensive syndrome. She initially presented with a history of behavioural abnormalities and hyponatraemia (126 mmol/l) and her blood pressure was as high as 220/160 mmHg. After admission, somnolence developed. Intravenous anti-hypertensive therapy was started immediately. The hyponatraemia was treated with i.v. sodium supplementation. The cause of this syndrome proved to be fibromuscular dysplasia of the left renal artery. Finally, a left nephrectomy was performed. With this therapy, blood pressure and serum sodium normalised and the girl promptly regained normal consciousness and behaviour.<bold>Conclusion: </bold>Behavioural abnormalities in the history of a child without any other neurological symptoms might be one of the first signs of hypertensive encephalopathy. In combination with hyponatraemia, these symptoms should alert the physician to consider the hyponatraemic hypertensive syndrome. [ABSTRACT FROM AUTHOR]