磁共振成像在脊髓型颈椎病中的应用

Application of Magnetic Resonance Imaging in Cervical Spondylotic Myelopathy

摘要: 脊髓型颈椎病(cervical spondylotic myelopathy, CSM)是成人常见的获得性脊髓功能障碍性疾病，传统磁共振成像主要用于评估颈髓受压形态及髓内信号改变，但其影像学表现与临床症状及预后之间并非完全一致。近年来，脑多模态MRI的发展使CSM的影像学研究由单纯描述局部脊髓受压逐渐拓展至整个中枢神经系统。现有证据表明，慢性颈髓压迫首先造成局部轴突、髓鞘及微循环损伤，并可能沿上、下行通路引发华勒变性和跨突触远隔神经退变；持续的感觉传入和运动传出障碍进一步导致感觉运动网络、丘脑–皮层环路、默认模式网络以及视觉–小脑网络发生结构与功能重组，同时伴随神经代谢、胶质反应和神经血管耦合异常。减压术后部分异常可出现动态逆转或重新组织，提示上述改变既包含不可逆神经损伤，也可能反映适应性或非适应性神经可塑性。此外，慢性疼痛、颈部功能障碍、情绪状态、认知表现、病程及性别等因素均可影响脑影像指标，是解释CSM幕上改变时不可忽视的潜在混杂因素。本文以“局部脊髓损伤–远隔神经变性–网络重组–术后恢复”为主线，整合定量脊髓MRI、结构MRI、弥散成像、功能MRI、磁共振波谱及灌注成像证据，以期为CSM影像生物标志物的建立及精准分层提供参考。

Abstract: Cervical spondylotic myelopathy (CSM) is a common cause of acquired spinal cord dysfunction in adults. Conventional magnetic resonance imaging (MRI) is primarily used to assess the morphology of cervical spinal cord compression and intramedullary signal abnormalities; however, imaging findings do not always correspond well with clinical manifestations or prognosis. In recent years, advances in multimodal brain MRI have expanded CSM imaging research from the characterization of localized spinal cord compression to a broader investigation of the entire central nervous system. Current evidence suggests that chronic cervical cord compression initially causes local axonal, myelin, and microvascular injury and may subsequently induce Wallerian degeneration and trans-synaptic remote neurodegeneration along ascending and descending pathways. Persistent disruption of sensory afferent and motor efferent signaling may further lead to structural and functional reorganization of the sensorimotor network, thalamocortical circuits, default mode network, and visual-cerebellar network, accompanied by abnormalities in neural metabolism, glial responses, and neurovascular coupling. Some of these alterations may partially reverse or undergo further reorganization after decompression surgery, suggesting that they reflect a combination of irreversible neural injury and adaptive or maladaptive neuroplasticity. In addition, chronic pain, neck disability, affective status, cognitive performance, disease duration, and sex may all influence cerebral imaging measures and should therefore be considered important potential confounders when interpreting supraspinal alterations in CSM. This review adopts a framework of “local spinal cord injury-remote neurodegeneration-network reorganization-postoperative recovery” to integrate evidence from quantitative spinal cord MRI, structural MRI, diffusion imaging, functional MRI, magnetic resonance spectroscopy, and perfusion imaging, with the aim of facilitating the development of imaging biomarkers and precision stratification in CSM.