Iatrogenic Hypothalamus Injury After Resection of Subependymoma Within the Left Brain Ventricle

Damage to the hypothalamus may result from direct surgical injury or from hemorrhage and ischemia caused by the procedure. Patients with hypothalamus damage can be comatose and exhibit hyperthermia. Here, we present a patient whose hypothalamus was directly damaged by a drainage catheter. His clinical manifestations included diabetes insipidus, hyperthermia and adrenocorticotropic hormone (ACTH) deficiency. The patient was a 48-year-old male and had a body weight of 95 kg. He was admitted to the hospital on August 31, 2019 for memory impairment and nonspecific dizziness that persisted for four months. A magnetic resonance image of the head showed an intraventricular mass attached to the anterior third of the septum pellucidum and Monro's foramen and enlargement of the left lateral ventricle. This intraventricular cystic tumor was 1.9 cm in diameter, without gadolinium enhancement. The tumor resection was performed without complications and with less bleeding than expected. The patient developed central diabetes insipidus within just two hours after the operation and presented with hyperthermia within six hours after the operation. ACTH deficiency was evident on day 1 after surgery. After we removed the catheter 19 hours after the operation, the patient never developed polyuria or high fever again. Two months later, his ACTH level was normal and never needed to take prednisone again. This unusual complication should be taken into account in patients who need external ventricular drains. Much attention should be paid to ensure that the length of the drainage catheter beneath the brain surface does not exceed 5 cm.