Radiological predictors of shunt response in the diagnosis and treatment of idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis

Table 15 The use of lacunae for prediction of shunt response in iNPH

Study	Sample size	Radiological methodology	Cutoff specification	Image specification	Image plane	Main reported outcomes
Hong et al. [20]	n = 31	•Manually counted by blinded neurologist	•Not specified	•3.0 Tesla MRI scanner was used to gain Axial fluid-attenuated inversion recovery (FLAIR), T2- weighted images	•Not specified	•There was a significant difference between SR (mean lacunae 0.1 ± 0.2) and SNR (mean: 1.1 ± 1.4) p = 0.009. Univariate analysis showed an OR: 0.161 •(95% CI: 0.021–1.269) was insignificant at p = 0.083. Multivariate analysis: OR: 0.000, p = 0.098
Murakami et al. [39]	n = 24	•Not specified	•Absence of lacunae	•Regional cerebral blood flow analysis through N-isopropyl-p-[123I] iodoamphetamine (IMP) enhanced Single-photon emission computed tomography (SPECT)	•Not specified	•Presence of lacunae was significantly associated with SNR (p = 0.0153). Sensitivity 71.4%, specificity:80%, PPV 83.3% and NPV 66.7%. TP 10, TN 8, FP 2, FN4

Studies included assessing the use of any advanced imaging radiological marker as predictor of shunt responsiveness. SR, shunt response; S-NR, shunt non-response; FLAIR, fluid-attenuated inversion recovery; SPECT, single-photon emission computerized tomography; NPV, negative predictive value; PPV, positive predictive value; TP, true positives; FP, false positives; TG, true negatives; FN, false negatives; OR, odds ratio; CI, confidence interval