Impact of Shunt-Related Hemorrhage on Seizure Development After Ventricular Shunt Surgery in Idiopathic Normal Pressure Hydrocephalus.

BACKGROUND AND OBJECTIVE: Ventricular shunt surgery, with either ventriculoperitoneal (VP) or ventriculoatrial (VA) shunts, is a primary treatment of idiopathic normal pressure hydrocephalus. However, postoperative seizures can complicate recovery. In this study, we investigated risk factors of postoperative seizures and assessed the risk of shunt-related hemorrhage. METHODS: Patients who underwent VP or VA shunt surgery for idiopathic normal pressure hydrocephalus between April 2020 and March 2023 were retrospectively reviewed. Exclusion criteria included a history of epilepsy or shunt revision surgery. Collected data included patient demographics, incidence of shunt-related intracranial hemorrhage, antithrombotic use, preoperative international normalized ratio, platelet count (within 2 weeks preoperatively), postoperative CRP levels (on day 1), time to seizure onset, and previous intracranial hemorrhage, cerebral infarction, or neurosurgery. Follow-up duration was recorded. RESULTS: This study enrolled 185 patients (102 men) with a mean age of 79.2 years (range: 53-94). Of these, 153 and 32 patients underwent VP and VA shunt surgery, respectively. Intracranial hemorrhage history was present in 9 patients (4.8%), cerebral infarction in 43 (23.2%), and previous intracranial surgery in 9 (4.8%). Hypertension was noted in 91 patients (49.1%). The mean CRP level on postoperative day 1 was 2.01 mg/dL (range: 0.05-14.99), whereas the mean preoperative international normalized ratio was 1.03 (range: 0.11-1.68). Shunt-related intracranial hemorrhage occurred in 14 patients (7.5%) and seizures in 8 (4%). Antithrombotic agents were used in 32 patients (17.2%). Patients with seizures had a higher incidence of shunt-related hemorrhage. Older age, previous intracranial surgery, and antithrombotic use were significantly associated with shunt-related hemorrhage. Logistic analysis identified shunt-related hemorrhage as a risk factor of seizures up to 2 years postoperatively. CONCLUSION: Our findings underscore the significance of shunt-related intracranial hemorrhage as a contributing factor to seizures after ventricular shunt surgery. This risk should be clearly communicated to patients during the informed consent process.