Teruo Kimura1, Shigeki Yamada2, Toshihide Sugimura3, Toshitaka Seki3, Makoto Miyano3, Shin Fukuda3, Makoto Takeuchi3, Shiro Miyata3, Adam Tucker4, Tsutomu Fujita5, Akira Hashizume6, Naoto Izumi7, Kazutsune Kawasaki7, Atsushi Nakagaki8, Kazuhiro Sako9. 1. Department of Neurosurgery, Dohtoh Neurosurgery Hospital, Hokkaidō, Japan; Department of Neurosurgery, Kitami Red Cross Hospital, Hokkaidō, Japan. Electronic address: tekimura-nsu@umin.ac.jp. 2. Department of Neurosurgery, Rakuwakai Otowa Hospital, Kyoto, Japan. 3. Department of Neurosurgery, Dohtoh Neurosurgery Hospital, Hokkaidō, Japan. 4. Department of Neurosurgery, Kitami Red Cross Hospital, Hokkaidō, Japan. 5. Department of Neurosurgery, Bihoro Clinic, Hokkaidō, Japan. 6. Department of Neurosurgery, Katsuragaoka Clinic, Hokkaidō, Japan. 7. Department of Neurosurgery, Abashiri Neurosurgery Rehabilitation Hospital, Hokkaidō, Japan. 8. Department of Computer Sciences, Kitami Institute of Technology, Kitami, Japan. 9. Department of Neurosurgery, Nayoro General Hospital, Nayoro City, Japan.
Abstract
BACKGROUND: Surgical treatment of iNPH by ventriculoperitoneal (VP) or lumboperitoneal (LP) shunting can achieve long-term recovery of activities of daily living (ADLs), however in a subset of patients maintenance of independence lasts for less than six months. This study examined positive preoperative predictive factors of short-term outcome for shunted iNPH patients. METHODS: Over a 9-year period, consecutive patients from multiple centers diagnosed with probable iNPH underwent either VP or LP shunt surgery. Preoperative variables of age, symptom duration, iNPH severity, tap test response, and MRI findings of disproportionately enlarged subarachnoid space hydrocephalus (DESH) or incomplete DESH were retrospectively evaluated in relation to 1-year postoperative outcome. RESULTS: Outcome for 154 shunt patients (12 VP, 142 LP) as measured by postoperative disability (mRS) and gait disturbance (iNPH-GD) was the same regardless of age. Symptom duration was inversely correlated with both iNPH severity (p<0.0001) and postoperative improvement at 1 year (P=0.0015). Severity also correlated inversely with postoperative improvement at 1 year (P<0.0001). Age was not significantly correlated with the degree of postoperative improvement (mRS: p=0.487; iNPHGS(GD): p=0.725). Outcome at one year (mRS, gait domain (Gd) and ADLs significantly improved in patients with a good response to the tap test (P<0.0001) Preoperative DESH correlated with improvement in mRS and GD (p<0.0001). CONCLUSIONS: Mild preoperative iNPH severity, shorter preoperative symptom duration, good tap test response, and complete DESH were associated with good short-term postoperative outcome at 1 year. These positive factors may be useful for prediction of short-term surgical outcome in iNPH patients.
BACKGROUND: Surgical treatment of iNPH by ventriculoperitoneal (VP) or lumboperitoneal (LP) shunting can achieve long-term recovery of activities of daily living (ADLs), however in a subset of patients maintenance of independence lasts for less than six months. This study examined positive preoperative predictive factors of short-term outcome for shunted iNPH patients. METHODS: Over a 9-year period, consecutive patients from multiple centers diagnosed with probable iNPH underwent either VP or LP shunt surgery. Preoperative variables of age, symptom duration, iNPH severity, tap test response, and MRI findings of disproportionately enlarged subarachnoid space hydrocephalus (DESH) or incomplete DESH were retrospectively evaluated in relation to 1-year postoperative outcome. RESULTS: Outcome for 154 shunt patients (12 VP, 142 LP) as measured by postoperative disability (mRS) and gait disturbance (iNPH-GD) was the same regardless of age. Symptom duration was inversely correlated with both iNPH severity (p<0.0001) and postoperative improvement at 1 year (P=0.0015). Severity also correlated inversely with postoperative improvement at 1 year (P<0.0001). Age was not significantly correlated with the degree of postoperative improvement (mRS: p=0.487; iNPHGS(GD): p=0.725). Outcome at one year (mRS, gait domain (Gd) and ADLs significantly improved in patients with a good response to the tap test (P<0.0001) Preoperative DESH correlated with improvement in mRS and GD (p<0.0001). CONCLUSIONS: Mild preoperative iNPH severity, shorter preoperative symptom duration, good tap test response, and complete DESH were associated with good short-term postoperative outcome at 1 year. These positive factors may be useful for prediction of short-term surgical outcome in iNPH patients.