Department of Neurology, Division of Clinical Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
Department of Physiology, Division of Biomedical Science, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
Curr Alzheimer Res. 2019;16(4):293-301. doi: 10.2174/1567205016666190311102130.
Classified as saccadic intrusions, Square-Wave Jerks (SWJs) have been observed during Visual Fixation (VF) in Alzheimer's Disease (AD). However, the pathological significance of this phenomenon remains unclear.
The present study analyzed the characteristics of SWJs in patients with AD with their eyes open in the dark without VF.
Fifteen patients with AD and 15 healthy age- and sex-matched controls were investigated and compared. Saccadic intrusions with and without VF were detected as SWJs and measured using an electronystagmogram.
No significant difference in the frequency of SWJs was observed between control and AD groups with VF, but significantly more SWJs were observed in the AD group than in the control group in the absence of VF (p<0.01). In the control group, the frequency of SWJs was significantly higher with VF as compared to without VF. Conversely, the frequency in the AD group was significantly higher without VF. Furthermore, a directly proportional relationship was observed between the frequency of SWJs and higher-order function (R>0.55) in the AD group.
SWJs without VF may have pathological significance in AD. In healthy individuals, SWJs are generated by VF and suppressed without VF. Conversely, in AD, SWJs are generated rather than suppressed in the absence of VF. These pathognomonic SWJs without VF also appear to be correlated with higher-order dysfunction, reflecting AD-related cortical damage. These findings suggest that pathological SWJs without VF observed in AD derive from cortical damage and may constitute an important marker of a higher-order function.
在阿尔茨海默病（AD）的视觉固定（VF）期间观察到，类扫视侵入（Square-Wave Jerks，SWJ）。然而，这种现象的病理意义尚不清楚。
本研究分析了 AD 患者在黑暗中睁眼且无 VF 时 SWJ 的特征。
对 15 名 AD 患者和 15 名年龄和性别匹配的健康对照组进行了调查和比较。使用眼动电图检测有无 VF 的情况下的扫视侵入，并用 SWJ 进行测量。
在有 VF 的情况下，对照组和 AD 组的 SWJ 频率无显著差异，但在无 VF 的情况下，AD 组的 SWJ 频率明显高于对照组（p<0.01）。在对照组中，有 VF 时 SWJ 的频率明显高于无 VF 时。相反，AD 组无 VF 时的频率明显更高。此外，在 AD 组中，SWJ 的频率与高级功能呈直接比例关系（R>0.55）。
无 VF 的 SWJ 在 AD 中可能具有病理意义。在健康个体中，SWJ 由 VF 产生并在无 VF 时被抑制。相反，在 AD 中，SWJ 在无 VF 时产生而不是被抑制。这些无 VF 的特征性 SWJ 似乎与高级功能障碍有关，反映了 AD 相关的皮质损伤。这些发现表明，AD 中观察到的无 VF 的病理性 SWJ 源自皮质损伤，可能是高级功能的重要标志物。
