Frontiers in neurology
Accuracy of CSF tap test and lumbar infusion test in predicting shunt response in idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis
By Aliyar A, Dash D, Fasano A and 8 others.
Abstract
Background
Idiopathic normal pressure hydrocephalus (iNPH) presents with gait disturbance, cognitive impairment, and urinary incontinence. The cerebrospinal fluid tap test (CSF-TT) and lumbar infusion test (LIT) are commonly used to predict postoperative improvement after shunt surgery; however, their validity remains debated.
Methods
We performed a systematic review and meta-analysis to assess the sensitivity and specificity of CSF-TT and LIT. The protocol was registered in PROSPERO (CRD42023454502). Reporting followed the PRISMA-DTA guidelines, and the certainty of evidence was assessed using the GRADE approach.
Results
Of 1,955 studies, 15 were included, reporting on 721 CSF-TT and 393 LIT patients, with shunt surgery as the reference standard. Nine CSF-TT studies (n = 700) and five LIT studies (n = 368) contributed to the primary meta-analysis. Considerable heterogeneity existed in test protocols, timing of assessment, and outcome measures. Several studies were retrospective with a high risk of bias. The pooled estimates were derived from a limited number of heterogeneous studies. Using a bivariate random-effects model, pooled sensitivity and specificity of CSF-TT were 64.1% (95% CI 49.2-76.6%, I 2 81.3%) and 54.8% (95% CI 41.8-67.2%, I 2 59.7%), respectively. The certainty of evidence was very low for sensitivity due to bias, inconsistency, and imprecision, and low for poor specificity due to bias and inconsistency. LIT showed a pooled sensitivity of 77.5% (95% CI 70.2-83.4%, I 2 14.7%) and a specificity of 28.3% (95% CI 19.0-39.9%, I 2 4.6%), with moderate certainty for sensitivity and moderate certainty for poor specificity.