The cerebrospinal fluid tap test (CSF TT) is used for selecting shunt surgery candidates among patients with idiopathic normal pressure hydrocephalus (iNPH). We aimed to evaluate the predictive value of the CSF TT, by using the Hellström iNPH scale for shunted iNPH patients with a standardized method. One hundred and sixteen shunt-operated iNPH patients were retrospectively included in this study. The gait and balance domains in the iNPH scale were used as outcome measures for the CSF TT and the total iNPH scale score as the postoperative outcome. A positive response to CSF TT was defined as a change of ≥ 5 points in the gait domain and ≥ 16 points in the balance domain. Differences between CSF TT responders and non-responders, sensitivity, specificity, positive and negative predictive values, accuracy, and correlations between changes from baseline to post CSF TT and from baseline to the postoperative follow-up, were calculated. In the CSF TT there were 63.8% responders in the gait domain and correspondingly 44.3% in the balance domain. CSF TT responders had a significantly better postoperative outcome in the total scale score (gait P ≤ 0.001, balance P ≤ 0.012) and gait CSF TT responders improved more in gait (P ≤ 0.001) and balance CSF TT responders in balance (P ≤ 0.001). No differences between CSF TT gait or balance responders could be found in neuropsychological or urinary continence assessments postoperatively. The sensitivity and specificity of the CSF TT and the outcome of the total iNPH scale score postoperatively were 68.1% and 52.0% for gait and 47.8% and 68.0% for balance, respectively. The CSF TT, with the Hellström iNPH scale as the outcome measure, has clear limitations in predicting postoperative results. The gait domain may be used to predict outcomes for gait, but the balance domain is too insensitive.

中文翻译：

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使用 Hellström iNPH 量表评估特发性正常压力脑积水患者的脑脊液抽吸试验

脑脊液抽吸试验 (CSF TT) 用于在特发性正常压力脑积水 (iNPH) 患者中选择分流手术候选者。我们旨在通过使用标准化方法对分流 iNPH 患者使用 Hellström iNPH 量表来评估 CSF TT 的预测价值。本研究回顾性纳入了 116 名分流手术 iNPH 患者。iNPH 量表中的步态和平衡域用作 CSF TT 的结果测量值，总 iNPH 量表评分作为术后结果。对 CSF TT 的阳性反应定义为步态领域的变化≥ 5 分，平衡领域的变化≥ 16 分。CSF TT 响应者和非响应者之间的差异、敏感性、特异性、阳性和阴性预测值、准确性、计算从基线到 CSF TT 和从基线到术后随访的变化之间的相关性。在 CSF TT 中，步态域中有 63.8% 的响应者，相应地平衡域中有 44.3% 的响应者。CSF TT 应答者的总评分（步态 P ≤ 0.001，平衡 P ≤ 0.012）的术后结果明显更好，步态 CSF TT 应答者的步态改善更多（P ≤ 0.001），平衡 CSF TT 应答者的平衡（P ≤ 0.001） ）。在术后神经心理学或尿控评估中未发现 CSF TT 步态或平衡反应者之间的差异。CSF TT 的敏感性和特异性以及术后 iNPH 总评分的结果分别为步态的 68.1% 和 52.0%，以及平衡的 47.8% 和 68.0%。CSF TT，以 Hellström iNPH 量表作为结果测量，在预测术后结果方面有明显的局限性。步态域可用于预测步态结果，但平衡域太不敏感了。