Brain Plasticity in Carpal Tunnel Syndrome and its Response to Acupuncture

描述（由申请人提供）：腕管综合征（CTS）是最常见的压迫性神经病变，仅次于腰痛，是导致员工缺勤的原因。一些神经影像学研究已经注意到CTS患者大脑中的神经可塑性不良，包括原发性体感皮层（SI）的改变和SI的过度激活，这可能是由于皮质去抑制所致。我们假设与CTS相关的残疾和疼痛不仅是周围神经损伤的结果，而且与观察到的皮质感觉处理改变有关。针刺作为CTS的一种保守治疗选择，但其作用机制尚不清楚。CTS是研究针灸机制的一个很好的模型，因为除了主观症状评估外，还可以通过几种客观结果测量来评估临床改善。我们提出，针刺作为一种体感条件刺激，可以通过使用依赖的可塑性逆转cts相关的不适应神经可塑性，包括皮质去抑制。此外，我们知道，在健康的大脑中，重复刺激会导致皮层活动在时间上的变化，其中最突出的是随着刺激持续时间的延长，皮层反应会减少。这被称为适应。已知皮质去抑制调节适应指标。我们提出，通过适应指标的不适应变化量化的皮质去抑制的生物行为评估将对CTS的大脑异常敏感。因此，这些指标补充了我们的fMRI数据，可能通过独立的测试方案提供重要的交叉验证。随机分配到verum针灸（前臂穴位）和安慰剂针灸组的CTS患者将用适应指标进行评估。我们假设verum，而不是假针灸会减轻CTS病理和增加皮质抑制，导致适应指标正常化。适应指标的改善将与fMRI生物标志物和正中神经功能障碍相关。因此，我们将结合生物行为测试和fMRI神经成像来更好地描述针灸改善CTS病理的主要机制。通过了解不同形式的针灸治疗的神经机制，我们希望完善针灸对CTS的效用，并在CTS护理中推进康复选择。

DESCRIPTION (provided by applicant): Carpal tunnel syndrome (CTS), the most common entrapment neuropathy, is exceeded only by low back pain as a cause of employee absenteeism. Maladaptive neuroplasticity in the brain of CTS patients has been noted by several neuroimaging studies, and includes altered primary somatosensory cortex (SI) somatotopy and SI hyperactivation, which may be due to cortical disinhibition. We hypothesize that the disability and pain associated with CTS is not only a consequence of the peripheral nerve lesion but also relates to the observed, altered cortical sensory processing. Acupuncture has shown potential as a conservative treatment option for CTS, but its mechanisms of action are unknown. CTS is an excellent model for studying acupuncture mechanisms as clinical improvement can be evaluated by several objective outcome measures in addition to subjective symptom assessments. We propose that acupuncture, a somatosensory conditioning stimulus, can reverse CTS-associated maladaptive neuroplasticity including cortical disinhibition via use-dependent plasticity. Furthermore, it is known that repetitive stimulation - in the healthy brain - results in temporally defined changes of cortical activity, the most prominent of which is a reduction in cortical response with extended stimulus duration. This is referred to as adaptation. Cortical disinhibition is known to modulate adaptation metrics. We propose that a biobehavioral assessment of cortical disinhibition quantified by maladaptive change in adaptation metrics will be sensitive to brain abnormalities in CTS. Thus, these metrics complement our fMRI data, potentially providing important cross-validation via an independent testing protocol. CTS patients randomized to verum acupuncture (forearm acupoints) and placebo acupuncture groups will be evaluated with adaptation metrics. We hypothesize that verum, but not sham acupuncture will alleviate CTS pathology and increase cortical inhibition, leading to normalization in adaptation metrics. Improvement in adaptation metrics will correlate with fMRI biomarkers and median nerve dysfunction. Hence, we will combine biobehavioral testing with fMRI neuroimaging to better delineate the central mechanisms by which acupuncture ameliorates CTS pathology. By understanding the neural mechanisms of different forms of acupuncture therapy, we hope to refine acupuncture utility for CTS and advance rehabilitation options in CTS care. PUBLIC HEALTH RELEVANCE: Carpal tunnel syndrome (CTS) is a very common ailment resulting from excessive compression of the median nerve in the wrist and consistently leads in lost work time among major disabling injuries. Acupuncture has shown potential as a conservative treatment option for CTS, but its mechanisms of action are not known. This grant will assess changes in brain activity and cortical disinhibition that accompany the dysfunction in the wrist, as well as how acupuncture might modify both local nerve health and brain function to help treat CTS patients.