LAUSR

Learning Objectives: Pneumocephalus after craniotomy will absorbs with in four weeks, but when air causes pressure effects it is a tension pneumocephalus, which may affect consciousness and requires immediate intervention. Tension pneumocephalus causing cerebral sinus thrombosis is not known in the literature. We report a case of tension pneumocephalus causing diabetes insipidus associated with cerebral sinus thrombosis. Methods: A 38-year-old male was admitted with a left frontal tumour extending into the lateral ventricle. The only significant past medical history was diarrhoea four days before admission. MRI showed normal cerebral sinuses and haemorrhage within the tumour and surrounding oedema. He subsequently underwent craniotomy and excision of tumour in a supine position. External ventricular and subdural drains were inserted at the end of surgery. Surgical time was 5 hours. At the end of surgery, return of consciousness was delayed. CT brain showed tension pneumocephalus. The subdural drain was manipulated and a gush of air obtained. He was kept sedated and ventilated in SICU. He became febrile, 39.2 °C, and pupils were 2 mm but reacting to light. Temperature was controlled with paracetamol and a cooling device. He had diabetes insipidus and received desmopressin 4 μg intravenously. He was rehydrated with 0.45% saline intravenously. On the first postoperative day MRI showed right transverse, sagittal sinus and right internal jugular vein thrombosis with complete left sided tumor resection. All thrombophilia markers were negative and cerebro-spinal fluid (CSF) analysis showed no bacterial growth. He was started on heparin anticoagulation. Two days after surgery his GCS improved to 11. Unfortunately on day3, pupils dilated and Fixed. Results: Tension pneumocephalus has a reported incidence of 9%. Transient diabetes insipidus has been reported in association with tension pneumocephalus. DI is a rare complication of tension pneumocephalus. our patient had cerebral sinus and internal jugular vein thrombosis with diffuse brain edema and brain death. This cerebral venous sinus thrombosis was on opposite side of the surgery, hence surgery was not the cause for cerebral venous sinus thrombosis (CVST). Our patient was at risk of developing tension pneumocephalus, because drained CSF during surgery and intraoperative received diuretics, steroids during surgery. In combination to tension pneumocephalus, severe dehydration due to DI, fever and medications may have resulted in CVST in our patient.