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Updated: Feb 17, 2026
Neuronavigation and Laparoscopy Guided Ventriculoperitoneal Shunt Insertion for the Treatment of Hydrocephalus
Published on: October 14, 2022
Timed up and go test at tap test and shunt surgery in idiopathic normal pressure hydrocephalus
Shigeki Yamada1, Masatsune Ishikawa1, Masakazu Miyajima1
1Normal Pressure Hydrocephalus Center (SY, MI), Department of Neurosurgery, Rakuwakai Otowa Hospital, Kyoto; Department of Neurosurgery (MM, MN), Juntendo University Graduate School of Medicine, Tokyo; Department of Neurosurgery (MA), Atsuchi Neurosurgical Hospital, Kagoshima; Department of Neurosurgery (TK), Dohtoh Neurosurgical Hospital, Hokkaido; Department of Molecular Pathobiology of Brain Diseases (Neurology) (TT), Kyoto Prefectural University of Medicine; Department of Psychiatry (HK), Osaka University Graduate School of Medicine; and Department of Behavioral Neurology and Cognitive Neuroscience (EM), Tohoku University Graduate School of Medicine, Miyagi, Japan.
Background:
The 3-meter Timed Up and Go test (TUG) is a reliable quantitative test for assessment of gait and balance. We aimed to establish an optimal threshold of TUG at the tap test for predicting outcomes 12 months after shunt surgery in patients with idiopathic normal pressure hydrocephalus (iNPH).
Methods:
The TUG was measured in a total of 151 patients with possible iNPH before and after a tap test and 12 months after shunt surgery. Among them, 81 patients underwent ventriculoperitoneal shunt implantation (SINPHONI) and 70 underwent lumboperitoneal shunt implantation (SINPHONI-2). The areas under the curve (AUCs), sensitivities, and specificities for predicting shunt effectiveness were assessed.
Results:
The simple differences of time on TUG at the tap test were significantly more accurate for predicting shunt effectiveness than percent improvement of time. The highest AUC for the synchronized moving cutoff point of TUG time was 0.81 (sensitivity 81.0%; specificity 81.6%) at the threshold of 5 seconds in the SINPHONI-2. For predicting improvements of ≥10 seconds 12 months after lumboperitoneal shunt implantation, the AUC was 0.90, and the sensitivity and specificity at the threshold of 5.6 seconds were 83.3% and 81.0%. Only for patients with a <5-second improvement at the tap test, ventriculoperitoneal shunt implantation conveyed significantly better improvements in TUG time 12 months after surgery than lumboperitoneal shunt implantation.
Conclusions:
An improvement of 5 seconds was a useful threshold of TUG time at the tap test for predicting a ≥10-second improvement 12 months after shunt surgery, rather than the percent improvement of TUG time.
