Park Eunhee, Kang Kyunghun, Lee Janghoon, Lee Jong Taek, Park Ki-Su, Kim Chul-Hyun, Min Yu-Sun
Department of Rehabilitation Medicine, School of Medicine, Kyungpook National University, # 807 Hoguk-Ro, Buk-Gu, Daegu, 41404, South Korea.
Department of Rehabilitation Medicine, Kyungpook National University Chilgok Hospital, Daegu, South Korea.
Neurol Ther. 2025 Jul 13. doi: 10.1007/s40120-025-00786-y.
In patients with idiopathic normal pressure hydrocephalus (iNPH), the characteristics of static steady-state balance disturbance are not as well understood as those related to gait. This study aimed to investigate differences in center of pressure (COP) parameters between patients with iNPH and age-matched healthy controls.
A total of 56 patients diagnosed with probable iNPH, who responded positively to cerebrospinal fluid tap test (CSFTT), along with 25 age-matched healthy controls, were enrolled. Prior to the CSFTT, COP measurements were taken using a force plate while participants stood quietly with eyes open (EO) and eyes closed (EC). We calculated the values of mediolateral (ML) and anteroposterior (AP) directions and ML/AP ratio in terms of the velocity of COP (vCOP), the standardized COP path length (Std_vCOP), and the peak power spectral density (PSD) at 0-0.5 Hz and 0.5-1.0 Hz. Additionally, we calculated the average distance from the COP center (Dist_COP) and the base of support (BOS). A Mann-Whitney U test with Bonferroni correction was used to compare differences between healthy controls and patients with iNPH under each visual condition (EO vs. EC).
There were no significant differences in gender, age, height, and weight between the healthy controls and the patients with iNPH. Patients with iNPH demonstrated greater spontaneous sway in the ML direction of vCOP (p < 0.001), increased variability in both ML and AP directions of Std_vCOP (p < 0.001 for both), a larger Dist_COP (p < 0.001) and BOS (p < 0.001) in the EC condition. Under the EO condition, patients with iNPH exhibited a significantly higher ML/AP ratio (p < 0.001) and larger BOS (p < 0.001). Furthermore, peak PSD at 0-0.5 Hz, reflecting low-frequency oscillations, was more pronounced in the ML direction and in the ML/AP ratio (p < 0.001 for both under EO), as well as in the AP direction (p < 0.001 under EC) in patients with iNPH. However, no significant differences were observed in the high-frequency oscillations (0.5-1.0 Hz).
These findings suggest that patients with iNPH exhibit distinct COP patterns, particularly greater variability in the ML direction during quiet standing. In contrast, the AP direction appears to be more influenced by visual conditions when compared to healthy controls. This result highlights the potential need for tailored balance training in patients with iNPH.
在特发性正常压力脑积水（iNPH）患者中，静态稳态平衡障碍的特征不如与步态相关的特征那样为人所熟知。本研究旨在调查iNPH患者与年龄匹配的健康对照者之间压力中心（COP）参数的差异。
共纳入56例被诊断为可能患有iNPH且脑脊液引流试验（CSFTT）反应阳性的患者，以及25名年龄匹配的健康对照者。在CSFTT之前，当参与者睁眼（EO）和闭眼（EC）安静站立时，使用测力台进行COP测量。我们根据COP速度（vCOP）、标准化COP路径长度（Std_vCOP）以及0 - 0.5Hz和0.5 - 1.0Hz处的峰值功率谱密度（PSD）计算了内外侧（ML）和前后（AP）方向的值以及ML/AP比率。此外，我们计算了距COP中心（Dist_COP）和支撑面（BOS）的平均距离。采用经Bonferroni校正的Mann-Whitney U检验来比较每种视觉条件下（EO与EC）健康对照者和iNPH患者之间的差异。
健康对照者和iNPH患者在性别、年龄、身高和体重方面无显著差异。iNPH患者在vCOP的ML方向上表现出更大的自发摆动（p < 0.001），Std_vCOP的ML和AP方向上的变异性均增加（两者均p < 0.001），在EC条件下Dist_COP（p < 0.001）和BOS（p < 0.001）更大。在EO条件下，iNPH患者表现出显著更高的ML/AP比率（p < 0.001）和更大的BOS（p < 0.001）。此外，反映低频振荡的0 - 0.5Hz处的峰值PSD在iNPH患者的ML方向和ML/AP比率中更明显（EO条件下两者均p < 0.001），在AP方向上（EC条件下p < 0.001）也是如此。然而，在高频振荡（0.5 - 1.0Hz）方面未观察到显著差异。
这些发现表明，iNPH患者表现出独特的COP模式，特别是在安静站立时ML方向上变异性更大。相比之下，与健康对照者相比，AP方向似乎受视觉条件的影响更大。这一结果凸显了对iNPH患者进行针对性平衡训练的潜在需求。
