title: Timing of surgical treatment for idiopathic normal pressure hydrocephalus: association between treatment delay and reduced short-term benefit.
abstract: OBJECTIVE A growing body of evidence suggests that longer durations of preoperative symptoms may correlate with worse postoperative outcomes following cerebrospinal fluid (CSF) diversion for treatment of idiopathic normal pressure hydrocephalus (iNPH). The aim of this study is to determine whether the duration of preoperative symptoms alters postoperative outcomes in patients treated for iNPH. METHODS The authors conducted a retrospective review of 393 cases of iNPH involving patients treated with ventriculoperitoneal (VP) shunting. The duration of symptoms prior to the operative intervention was recorded. The following outcome variables were assessed at baseline, 6 months postoperatively, and at last follow-up: gait performance, urinary continence, and cognition. RESULTS The patients' median age at shunt placement was 74 years. Increased symptom duration was significantly associated with worse gait outcomes (relative risk (RR) 1.055 per year of symptoms, p = 0.037), and an overall absence of improvement in any of the classic triad symptomology (RR 1.053 per year of symptoms, p = 0.033) at 6 months postoperatively. Additionally, there were trends toward significance for symptom duration increasing the risk of having no 6-month postoperative improvement in urinary incontinence (RR 1.049 per year of symptoms, p = 0.069) or cognitive symptoms (RR 1.051 per year of symptoms, p = 0.069). However, no statistically significant differences were noted in these outcomes at last follow-up (median 31 months). Age stratification by decade revealed that prolonging symptom duration was significantly associated with lower Mini-Mental Status Examination scores in patients aged 60-70 years, and lack of cognitive improvement in patients aged 70-80 years. CONCLUSIONS Patients with iNPH with longer duration of preoperative symptoms may not receive the same short-term benefits of surgical intervention as patients with shorter duration of preoperative symptoms. However, with longer follow-up, the patients generally reached the same end point. Therefore, when managing patients with iNPH, it may take longer to see the benefits of CSF shunting when patients present with a longer duration of preoperative symptoms.
authors: Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Sharif
authors: S
authors: Vakili
authors: Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Dane
authors: D
authors: Moran
authors: Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Alice
authors: A
authors: Hung
authors: Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Benjamin D
authors: BD
authors: Elder
authors: Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Lee
authors: L
authors: Jeon
authors: Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Hugo
authors: H
authors: Fialho
authors: Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Eric W
authors: EW
authors: Sankey
authors: Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Ignacio
authors: I
authors: Jusué-Torres
authors: Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: C Rory
authors: CR
authors: Goodwin
authors: Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Jennifer
authors: J
authors: Lu
authors: Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Jamie
authors: J
authors: Robison
authors: Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Daniele
authors: D
authors: Rigamonti
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000175:diagnosis* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018570:Risk Assessment; D013997:Time Factors; D061665:Time-to-Treatment / Q000639:trends*; D016896:Treatment Outcome
keywords: CSF = cerebrospinal fluid; MMSE = Mini-Mental Status Examination; RR = relative risk; VP = ventriculoperitoneal; VP shunt; cognitive decline; gait abnormality; iNPH = idiopathic normal pressure hydrocephalus; idiopathic normal pressure hydrocephalus; incontinence