Early Shunting Promotes Sustained Improvement of Patients with Idiopathic Normal Pressure Hydrocephalus: A Multicenter Retrospective Study

Background: Idiopathic normal pressure hydrocephalus (iNPH) is the only reversible cause of dementia, but many patients fail to receive shunt surgery in time due to underdiagnosis. This study aimed to determine the relationship between surgery timepoint and sustained postoperative improvement in patients with iNPH. Methods: We divided the patients into the early surgery group (0–3 months) and the late surgery group (> 3 months) according to the duration from the disease onset to surgery. Patients from 3 general hospitals in different provinces of China were included. Primary endpoints included improvements on the idiopathic normal pressure hydrocephalus grading scale (INPHGS) and modified Rankin Scale (mRS). Results: A total of 120 patients were included in the study. The mean age was 62.76 ± 12.27, the mean duration of symptoms was 22.00 ± 37.99 months, the mean INPHGS was 7.15 ± 1.759 (cognitive: 2.71 ± 0.91; gait: 2.47 ± 0.95; urinary: 1.96 ± 0.88), and the mean mRS were 2.45 ± 0.77. In the early surgery group, patients’ symptoms improved continuously from discharge to 1-year follow-up. Regarding mRS improvement, the early surgery group is superior to the late surgery group at postoperative time points and 1-year follow-up (p < 0.05). Conclusions: The results of this multicenter study indicate that early shunting promotes sustained improvement in patients with iNPH.