This study is a prospective observational registry study that enrolls all patients aged 60 years or older suspected of having idiopathic normal pressure hydrocephalus based on the Third Edition of the Guidelines for the Diagnosis and Treatment of Idiopathic Normal Pressure Hydrocephalus. From the cohort registered, patients judged to be candidates for surgery based on the 3rd Edition of the Guidelines for the Diagnosis and Treatment of Idiopathic Normal Pressure Hydrocephalus. These patients will be randomized 1:1 to undergo either ventriculoperitoneal shunt surgery under general anesthesia or lumbar peritoneal shunt surgery under local anesthesia. A randomized clinical trial would attest the non-inferiority of lumbar peritoneal shunt surgery under local anesthesia compared to ventriculoperitoneal shunt surgery under general anesthesia regarding the improvement in timed up-and-go test scores at 3 months post-surgery relative to pre-surgery levels.

Inclusion Criteria:

• Probable iNPH patients
• Age 60 years or older at the time of the tap test
• Patients capable of performing the Timed Up and Go test
• Patients assignable within 2 weeks (14 days) of obtaining RCT consent
• Patients capable of undergoing shunt surgery within 1 month (30 days) of assignment
• Patients capable of follow-up at the assigned facility or referring facility for 12 months after assignment
• Patients for whom informed consent was obtained

Exclusion Criteria:

• Patients deemed unsuitable for lumbar-abdominal shunt surgery due to advanced degeneration of the lumbar spine and spinal canal, etc.
• Patients deemed unsuitable for abdominal shunt surgery due to a history of multiple open abdominal surgeries, a history of severe intra-abdominal infection, etc.
• Other patients deemed unsuitable by the attending physician