Long-term 4 Years Follow-up Study of 482 Patients Who Underwent Shunting for Idiopathic Normal Pressure Hydrocephalus -Course of Symptoms and Shunt Efficacy Rates Compared by Age Group-

摘要

A total of 482 operated idiopathic normal pressure hydrocephalus (iNPH) patients were divided into those aged 80 years at the time of surgery (group A: 400 cases; and male-to-female ratio, 259:141) and ≥80 years (group B: 82 cases; male-to-female ratio, 43:39) and comparatively investigated based on the following variables: (1) temporal changes in shunt efficacy rates, and (2) temporal changes in each symptom, including the patient’s fall frequency and preoperative modified Rankin Scale (mRS) score and during follow-up at 3, 6 months, 1–4 years postoperatively. (1) The shunt efficacy rates at 3 months and 4 years postoperatively were 93% and 82%, respectively, in group A and 92.3% and 70.7%, respectively, in group B. This demonstrates a decrease in shunt efficacy at 4 years postoperatively, regardless of the persistence of shunt function or adjustments in setting pressure. This trend was particularly observed in group B. In group A, 41 (9.8%) cases had decreased efficacy rate, compared with 21 (25.6%) cases in group B, which occurred due to complications with an extracranial or intracranial disease. (2) Gait disturbance ( G ) and urinary incontinence ( U ) showed signs of improvement in the early postoperative stage, while dementia ( D ) and mRS score began to gradually improve from 6 months postoperatively. Patient’s fall frequency tended to become higher until 6 months postoperatively than the preoperative rate. In group A, symptom improvement was comparatively maintained until 4 years postoperatively, while in group B, all symptoms and mRS tended to gradually deteriorate beginning at 3 years postoperatively.