Simó Magdolna, Arányi Zsuzsanna
Semmelweis Egyetem, Altalános Orvostudományi Kar, Neurológiai Klinika, H-1083 Budapest, Balassa u. 6.
Ideggyogy Sz. 2003 Jan 20;56(1-2):51-7.
Motor evoked potential (MEP) is the only method that is able to assess the function of the corticospinal tract in various neurological conditions, such as myelopathies. Myelopathy associated with cervical spondylosis, especially at an early stage, has often slight and non-specific clinical signs, pointing to the importance of the electrophysiological assessment of the spinal cord. The authors' aim was to investigate the sensitivity of MEP examination in the detection of myelopathy secondary to cervical spondylosis.
Patients were classified into three groups according to clinical signs and symptoms: Group I includes patients who have cervical spondylosis as demonstrated by MRI (narrowing of the spinal canal, discal herniation, spinal cord compression) but no complaints or signs suggestive of myelopathy.
In Group II patients had minor, non-specific complaints, such as paraesthesia of the legs and gait disturbance raising the possibility of myelopathy, but neurological examination revealed no pyramidal signs. In Group III patients had pyramidal signs as well. In Group I corticospinal function was normal in all patients, as assessed by MEP examination. In Group II all patients had prolonged central motor conduction time or absent responses to cortical stimulation. Likewise, in Group III MEP revealed abnormal corticospinal function in all patients but one.
In summary, MEP proved sensitive in the detection of corticospinal dysfunction in myelopathy associated with cervical spondylosis at a stage when clinical signs of pyramidal lesion are not yet present and patients have only minor complaints. On the other hand, if patients are completely symptom free with regard to myelopathy, MEP is also unlikely to disclose corticospinal dysfunction. If pyramidal lesion is evident already by clinical examination, MEP provides no further help. 'False-negative' results are also possible.
运动诱发电位（MEP）是唯一能够在各种神经系统疾病（如脊髓病）中评估皮质脊髓束功能的方法。与颈椎病相关的脊髓病，尤其是在早期，通常具有轻微且非特异性的临床体征，这凸显了脊髓电生理评估的重要性。作者的目的是研究MEP检查在检测颈椎病继发脊髓病方面的敏感性。
根据临床体征和症状将患者分为三组：第一组包括经MRI证实患有颈椎病（椎管狭窄、椎间盘突出、脊髓受压）但无提示脊髓病的主诉或体征的患者。
第二组患者有轻微、非特异性的主诉，如腿部感觉异常和步态障碍，增加了脊髓病的可能性，但神经系统检查未发现锥体束征。第三组患者也有锥体束征。通过MEP检查评估，第一组所有患者的皮质脊髓功能均正常。第二组所有患者的中枢运动传导时间延长或对皮质刺激无反应。同样，第三组除一名患者外，所有患者的MEP均显示皮质脊髓功能异常。
总之，在锥体束病变的临床体征尚未出现且患者仅有轻微主诉的阶段，MEP在检测与颈椎病相关的脊髓病中的皮质脊髓功能障碍方面被证明是敏感的。另一方面，如果患者在脊髓病方面完全没有症状，MEP也不太可能揭示皮质脊髓功能障碍。如果临床检查已明显发现锥体束病变，MEP则无法提供更多帮助。“假阴性”结果也是可能的。
