Life threatening hyponatraemia following evacuation of spontaneous chronic subdural haematoma

We report the case of a 43-year-old woman who developed life threatening hyponatraemia 4 days following burr hole drainage of a spontaneous chronic subdural haematoma (CSDH). Syndrome of inappropriate secretion of antidiuretic hormone was confirmed. This is the first report of delayed life threatening hyponatraemia developing postoperatively in CSDH. The mechanism remains unclear but may involve brain shift on the pituitary stalk following subdural evacuation.