A 69-year-old woman with a 24-year history of Parkinson’s disease and the use of a variety of antiparkinsonian drugs was admitted on February 27, 2014. Her disease had gradually progressed, and the drugs were less effective, despite increased dosages and changes in drug families. Before admission, she had been experiencing serious motor complications, including wearing-off and dyskinesia, and she was taking levodopa/benserazide 500 mg/day, carbidopa/levodopa 500 mg/day, selegiline 12.5 mg/day, trastal 150 mg/day and amantadine 100 mg/day. After admission, the drugs were gradually discontinued in order to alleviate the dyskinesia (Fig. 1). However, it had no effect. A levodopa test, which compared the Unified Parkinson Disease Rating Scale Part III (motor score) before and after oral intake of levodopa, showed a more than 30% improvement, which indicated that the patient was a suitable candidate for STN-DBS. Bilateral STN stimulation was commenced 5 days after admission. Eight hours before surgery, all PD medications were stopped. Bilateral STN-DBS was performed as described in the literature [4]. During the procedure, the patient was cooperative but exhausted. After recovering from the general anesthesia, the patient was unable to communicate properly. During the night, the patient developed severe muscle rigidity, tremors, continuous limb shaking, head tremor and trismus. She was febrile, with a temperature of 39.8°C, and had diaphoresis, a pulse rate of 132 beats/min, a respiratory rate of 24 breaths/min, and sustained increasing in blood pressure up to 178/117 mmHg. Her consciousness gradually declined approximately 11 h after DBS. Laboratory tests were normal with the exception of an elevated white blood cell count (18.0 × 109/L). A computed tomography (CT) scan of the brain showed correct placement of the electrodes without evidence of blood or other abnormalities. The next day, the patient was admitted to the intensive care unit. Intravenous fluid replacement and cooling of the body were initiated, and complications were managed. In the next 7 days, a series of tests were run to determine the cause of her condition. An evaluation to determine potential sources of infection was unrevealing. The evaluation of her febrile condition included a chest x-ray, thyroid function tests, routine stool tests, routine urine tests and a bacterial culture analysis; however, causative factors were not identified. A cerebrospinal fluid (CSF) examination was also normal. On the day of surgery and on postoperative days 1, 2, 3, 6, and 12, brain CT showed normal postoperative changes; however, a left frontal cerebral infarction occurred on the 2nd day after the operation (Fig. 2). On day 7 postoperatively, when infection, cerebral infarction and intracerebral hemorrhage were all excluded, the diagnosis of PHS was made. Antiparkinsonian medications were immediately reinstated, and the patient’s symptoms began to improve. Levodopa/benserazide was initiated at 250 mg/day and increased to 500 mg/day, trastal was initiated at 25 mg/day and increased to 150 mg/day, and amantadine 100 mg/day per day was initiated (Fig. 1). By the 28th day after surgery, the patient’s condition had gradually returned to her preoperative status. Her consciousness recovered, and her vital signs and laboratory tests returned to baseline levels (Fig. 3).