Exploring the pathophysiology of mal de debarquement.
Exploring the pathophysiology of mal de debarquement.
复制标题
探索 mal de debarquement 的病理生理学。
DOI：
10.1007/s00415-010-5867-y
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发表时间：
2011
影响因子：
6
通讯作者：
Quick,Adam
中科院分区：
文献类型：
--
作者：
Clark,BrianC;Quick,Adam
脱机综合症（MdDS）是一种感知运动的障碍，最常发生在巡航后。我们报告了一位MdDS患者的发现，他接受了经颅磁刺激方案来量化皮质兴奋性。这些数据与40个对照组的数据进行了比较。MdDS患者表现出高水平的皮质内便利化。这些发现将为MdDS的病理生理学提供见解，并将有助于指导未来对这种罕见疾病的研究。当对被动背景运动的习惯对稳定条件的重新适应产生抵抗并导致对自我运动的幻像感知时，就会发生脱缰综合症。MdDS通常在返回稳定地面后迅速消失；然而，在极少数情况下，症状可能持续数月至数年（持续性MdDS）。虽然对持续性MdDS的病因了解甚少，但它似乎不是源于前庭功能障碍，因为前庭检查正常，症状对前庭治疗无反应。相反，MdDS似乎是一种神经可塑性和感觉重排紊乱。据我们所知，还没有研究检查这种疾病的神经生理特征。在本病例研究中，我们报告了一名持续性MdDS患者的发现，该患者接受了广泛的经颅磁刺激（TMS）方案来量化运动皮质兴奋性。具体来说，我们使用单脉冲TMS量化皮质脊髓沉默期的持续时间。当受试者进行轻微收缩并对运动皮层施加单次TMS刺激时，观察到沉默期（图1a）。此外，我们使用双脉冲TMS量化了皮质内促进（ICF）和短间隔皮质内抑制（SICI）。配对脉冲经颅磁刺激将条件刺激（CP）和测试刺激（TP）在不同的刺激间隔中结合起来，运动诱发电位（MEP）大小的相对变化是相对于非条件测试脉冲来表达的。在较短的3 ms间刺激间隔下，CP抑制MEP (SICI)，而在较长的15 ms间刺激间隔下，CP促进MEP (ICF)（图2）。1 b)。患者为一名63岁女性（160.2 cm, 77.3 kg）， 3.5年前（3/2007）从7天游轮下船后，主诉有不稳定感和脚下地板移动的感觉。她报告说，她不得不经常伸出手来稳定自己，以对抗固定的物体，MdDS极大地影响了她的生活质量(在视觉模拟量表上，MdDS对她生活质量的影响的主观评分为6分（满分为10分）。MdDS的其他几个标志性特征包括轻度认知减慢和再次暴露于被动运动[2]后症状的短暂改善。体格检查无明显异常。诊断测试包括腓肠感觉和腓神经运动传导研究，脑针肌电图和MRI均正常。此外，患者在Dix-Hallpike试验和热量反射试验中没有明显的发现。患者没有偏头痛或其他国际标准定义的原发性头痛
Mal de debarquement syndrome (MdDS) is a disorder of perceived motion most often occurring following a cruise. We report findings from a patient with MdDS who underwent a transcranial magnetic stimulation protocol to quantify cortical excitability. These data were compared to those from 40 controls. The patient with MdDS exhibited high levels of intracortical facilitation. These findings will provide insight on the pathophysiology of MdDS, and will help guide future work on this rare condition. Mal de debarquement syndrome (MdDS) occurs when habituation to passive background movement becomes resistant to readaptation to stable conditions and results in a phantom perception of self-motion. MdDS typically disappears quickly after return to stable ground; however, in rare instances the symptoms may persist for months to years (persistent MdDS). While the etiology of persistent MdDS is poorly understood, it does not appear to originate from vestibular dysfunction as vestibular tests are normal and the symptoms do not respond to vestibular therapy [2]. Rather, MdDS appears to be a disorder of neuroplasticity and sensory rearrangement [2]. To our knowledge, there have been no studies examining the neurophysiologic characteristics of the disorder. In this case study we report findings from a patient with persistent MdDS who underwent an extensive transcranial magnetic stimulation (TMS) protocol to quantify motor cortical excitability. Specifically, we quantified the duration of the corticospinal silent period using single-pulse TMS. The silent period is observed when a subject performs a slight contraction and a single TMS stimulus is applied to the motor cortex (Fig. 1 a). Additionally, we quantified intracortical facilitation (ICF) and short-interval intracortical inhibition (SICI) using paired-pulse TMS. Paired-pulse TMS combines a conditioning stimulus (CP) with a test stimulus (TP) at different interstimulus intervals, and the relative change in motor evoked potential (MEP) size is expressed relative to an unconditioned test pulse. At a short interstimulus interval of 3 ms, the CP inhibits the MEP in comparison to the TP only (SICI), whereas at a longer interstimulus intervals of 15 ms it facilitates the MEP (ICF)(Fig. 1 b).The patient was a 63-year-old female (160.2 cm, 77.3 kg) who complained of sensations of unsteadiness and a feeling of the floor moving under her feet after disembarking from a 7-day cruise* 3.5 years ago (3/2007). She reported having to regularly reach out to steady herself against stationary objects, and that MdDS had greatly impacted her quality of life (subjective scoring of six out of ten on a visual analog scale for the impact of MdDS on her quality of life). Several other hallmark features of MdDS were present including mild cognitive slowing and transient improvement in symptoms with re-exposure to passive movement [2]. Physical examination was unremarkable. Diagnostic testing including sural sensory and peroneal motor conduction studies, needle EMG, and MRI of the brain were all normal. Additionally, the patient had unremarkable findings on Dix-Hallpike testing and the caloric reflex test. The patient did not have migraine or other primary headache as defined by the International