[Systematic review of complications for proper informed consent(13)stereotactic and functional neurosurgery]

We conducted a systematic review to assess the incidence of various surgical complications both during and after stereotactic and functional neurosurgery. Initially, we considered that surgical complications and the adverse effects of stimulation should be differentiated. In some reports, intracranial hemorrhage, infection, device-related problems, and epileptic seizure have been regarded as major and serious surgical complications. The established rates of hemorrhagic complications are 3.7%[95% confidence interval(CI):2.8-4.6%]for coagulation surgery and 4.6%(95% CI:3.8-5.3%)for deep brain stimulation(DBS). However, the rates of significant permanent neurological deficits originating from hemorrhage were relatively low. The average rates were 1.2%(95% CI:0.7-1.6%)for coagulation surgery and 1.0%(95% CI:0.6-1.3%)for DBS. Almost all of the patients with infectious complications had undergone DBS, and these complications were very rarely encountered after coagulation surgery. The rate of the occurrence of infection in DBS patients was 4.0%(95% CI:3.5-4.5%). Device-related problems were complications of DBS, and the main problems were migration and fracture. Epileptic seizure was noted in 0.4%(95% CI:0.1-0.7%)of the patients who underwent coagulation surgery and in 3.2%(95% CI:2.3-4.0%)of those who underwent DBS. The actual rate of occurrence of epileptic seizure was speculated to be much lower than the above rate because we did not include analytical reports that did not mention epileptic seizure. The exact rate of the occurrence of adverse effects caused by DBS was difficult to determine. Skill in the programming of the stimulation parameters, disease progression, and the balance between drugs and stimulation may affect the postoperative adverse events. However, we can advise patients and their families of the potential for psychiatric symptoms, depression, and cognitive dysfunction, which could seriously infringe on the patient's quality of life, after DBS.