University Groningen, University Medical Center Groningen, Department of Neurology, NL-9700 RB, Groningen, The Netherlands.
University Groningen, University Medical Center Groningen, Department of Neurology, NL-9700 RB, Groningen, The Netherlands; Department of Neurology, Haga Teaching Hospital, The Hague, The Netherlands.
Parkinsonism Relat Disord. 2018 Jun;51:3-8. doi: 10.1016/j.parkreldis.2018.03.029. Epub 2018 Apr 6.
Differentiating between functional jerks (FJ) and organic myoclonus can be challenging. At present, the only advanced diagnostic biomarker to support FJ is the Bereitschaftspotential (BP). However, its sensitivity is limited and its evaluation subjective. Recently, event related desynchronisation in the broad beta range (13-45 Hz) prior to functional generalised axial (propriospinal) myoclonus was reported as a possible complementary diagnostic marker for FJ. Here we study the value of ERD together with a quantified BP in clinical practice.
Twenty-nine patients with FJ and 16 patients with cortical myoclonus (CM) were included. Jerk-locked back-averaging for determination of the 'classical' and quantified BP, and time-frequency decomposition for the event related desynchronisation (ERD) were performed. Diagnostic gain, sensitivity and specificity were obtained for individual and combined techniques.
We detected a classical BP in 14/29, a quantitative BP in 15/29 and an ERD in 18/29 patients. At group level we demonstrate that ERD in the broad beta band preceding a jerk has significantly higher amplitude in FJ compared to CM (respectively -0.14 ± 0.13 and +0.04 ± 0.09 (p < 0.001)). Adding ERD to the classical BP achieved an additional diagnostic gain of 53%. Furthermore, when combining ERD with quantified and classical BP, an additional diagnostic gain of 71% was achieved without loss of specificity.
Based on the current findings we propose to the use of combined beta ERD assessment and quantitative BP analyses in patients with a clinical suspicion for all types of FJ with a negative classical BP.
区分功能性痉挛（FJ）和器质性肌阵挛具有一定挑战性。目前，唯一支持 FJ 的高级诊断生物标志物是准备电位（BP）。然而，其敏感性有限，评估具有主观性。最近，功能性全身轴性（ propriospinal ）肌阵挛前宽β频带（13-45Hz）的事件相关去同步化被报道为 FJ 的一种可能的补充诊断标志物。在此，我们在临床实践中研究 ERD 与量化 BP 的价值。
共纳入 29 例 FJ 患者和 16 例皮质肌阵挛（CM）患者。通过后平均法确定“经典”和量化 BP，并进行时频分解以确定事件相关去同步（ERD）。获得了个体和联合技术的诊断增益、敏感性和特异性。
我们在 14/29 例患者中检测到经典 BP，在 15/29 例患者中检测到量化 BP，在 18/29 例患者中检测到 ERD。在组水平上，我们发现 FJ 患者在痉挛前宽β带中的 ERD 振幅明显高于 CM（分别为-0.14±0.13 和+0.04±0.09（p<0.001））。将 ERD 添加到经典 BP 中可额外获得 53%的诊断增益。此外，当将 ERD 与量化和经典 BP 相结合时，在不降低特异性的情况下，额外获得了 71%的诊断增益。
基于目前的发现，我们建议对所有类型 FJ 患者（具有阴性经典 BP）的临床疑似病例使用组合的β-ERD 评估和量化 BP 分析。
