Abstracts

Rationale: The development of diabetes insipidus (DI) commonly occurs after sellar region surgery, but rarely after surgery for epilepsy. Here, we investigated the clinical course and characteristics of patients with DI after epilepsy surgery. Methods: We retrospectively reviewed the medical records of pediatric patients who underwent epilepsy surgery at the National Center of Neurology and Psychiatry in Japan between 2007 to 2015 and experienced complications of diabetes insipidus. Diagnosis of central DI was based on 1) polyuria; 2) an abnormally high serum osmolality; 3) a high serum sodium level; 4) abnormally low urine osmolality; and 5) effective control of polyuria after treatment with arginine vasopressin (AVP). Results: We evaluated three patients who and fulfilled our criteria. All had a hemispherotomy. Case 1 was a female infant with Sturge-Weber syndrome who underwent surgery at 4 months of age. A computed tomography (CT) scan performed on postoperative day (POD) 1 revealed an infarction of the left frontal and parietal lobe with a midline shift. On POD 2, we observed polyuria, low osmolar urine and an elevated serum sodium concentration. After AVP administration, a rapid decrease in the serum sodium concentration, resulted in generalized tonic clonic convulsions (GTCC). The patient required the administration of AVP until POD 11, with a temporary cessation due to a low serum sodium concentration. Case 2 was a male infant with left hemimegalencephaly who underwent surgery at the age of 3 months. Polyuria and hypernatremia developed on POD 1. A CT scan revealed thrombosis in the right transverse sinus, and anticoagulant therapy was provided until the thrombosis disappeared. Subsequently, hyponatremia with an increased urine sodium concentration developed on POD 4. AVP was administrated according to his sodium concentration. He had 4 GTCC episodes up until POD 10, while his serum sodium concentration was low. Case 3 was a female infant with right hemimegalencephaly who underwent surgery at the age of 2 months. Her urine output began to increase 8 hours after the surgery. On POD 1, her serum sodium concentration surged to 170 mEq/L and AVP infusion was initiated. On POD 2, she developed sinus thrombosis in the right transverse sinus and was administered anticoagulation therapy. On POD 3, serum sodium concentration rapidly decreased; hence, her sodium concentration was rapidly restored, but she had a GTCC, which led to an interruption of AVP infusion. On POD 8, AVP administration resumed, and beginning POD 15, she was administered nasal deamino AVP for 2 months. Conclusions: Although, we could not confirm the causes of the DI in our cases, increased cranial pressure, and edema around the sellar area might have been involved. Hypernatremic dehydration and a rapid change in sodium concentration could have caused the sinus thrombosis and convulsions, respectively. Our results suggest that young patients who undergo epilepsy surgery should have their urine output and serum electrolytes carefully monitored. Funding: No funding was received for this study.