BACKGROUND Following Bayes theorem, ventriculomegaly and ataxia confer only a 30% chance of idiopathic Normal Pressure Hydrocephalus (NPH). When coupled with positive responses to best diagnostic testing (extended lumbar drainage), 70% of patients recommended for shunting will not actually have NPH. This is inadequate clinical care. OBJECTIVE To determine the proportion of alternative and treatable diagnoses in patients referred to a multidisciplinary NPH clinic. METHODS Patients without previously diagnosed NPH were queried from prospectively collected data. At least 1 neurosurgeon, cognitive neurologist, and neuropsychologist jointly formulated best treatment plans. RESULTS Of 328 total patients, 45% had an alternative diagnosis; 11% of all patients improved with treatment of an alternative diagnosis. Of 87 patients with treatable conditions, the highest frequency of pathologies included sleep disorders, and cervical stenosis, followed by Parkinson disease. Anti-cholinergic burden was a contributor for multiple patients. Of 142 patients undergoing lumbar puncture, 71% had positive responses and referred to surgery. Compared to NPH patients, mimickers were statistically significantly older with lower Montreal Cognitive Assessment (MoCA) score and worse gait parameters. Overall, 26% of the original patients underwent shunting. Pre-post testing revealed a statistically significant improved MoCA score and gait parameters in those patients who underwent surgery with follow-up. CONCLUSION Because the Multidisciplinary NPH Clinic selected only 26% for surgery (corroborating 30% in Bayes theorem), an overwhelming majority of patients with suspected NPH will harbor alternative diagnoses. Identification of contributing/confounding conditions will support the meticulous work-up necessary to appropriately manage patients without NPH while optimizing clinical responses to shunting in correctly diagnosed patients.

中文翻译：

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特发性正常压力脑积水患者替代诊断的流行率和治疗意义

背景根据贝叶斯定理，脑室扩大和共济失调仅赋予 30% 的特发性正常压力脑积水 (NPH) 机会。再加上对最佳诊断测试（延长腰椎引流术）的阳性反应，被推荐进行分流术的 70% 的患者实际上不会患有 NPH。这是临床护理不足。目的 确定转诊至多学科 NPH 诊所的患者中替代诊断和可治疗诊断的比例。方法 从前瞻性收集的数据中查询先前未诊断出 NPH 的患者。至少 1 位神经外科医生、认知神经学家和神经心理学家共同制定了最佳治疗方案。结果 在总共 328 名患者中，45% 有其他诊断；11% 的患者在接受替代诊断的治疗后有所改善。在 87 名可治疗的患者中，发病频率最高的疾病包括睡眠障碍和颈椎管狭窄，其次是帕金森病。多个患者的抗胆碱能负担是一个贡献者。在 142 名接受腰椎穿刺的患者中，71% 有阳性反应并转诊至手术治疗。与 NPH 患者相比，模仿者的年龄显着高于蒙特利尔认知评估 (MoCA) 评分和步态参数。总体而言，26% 的原始患者接受了分流术。前后测试显示，在接受手术和随访的患者中，MoCA 评分和步态参数在统计学上显着改善。结论 由于多学科 NPH 诊所仅选择了 26% 进行手术（在贝叶斯定理中证实了 30%），绝大多数疑似 NPH 的患者将有其他诊断。