Tani T, Yamamoto H, Kimura J
Department of Orthopaedic Surgery, Kochi Medical School, Nankoku City, Japan.
J Neurol Neurosurg Psychiatry. 1999 Apr;66(4):456-64. doi: 10.1136/jnnp.66.4.456.
To precisely localise the site of conduction block in elderly patients with cervical spondylotic myelopathy in the presence of multilevel compression shown by MRI.
A total of 44 patients aged 65 and older underwent serial intervertebral recording of spinal somatosensory evoked potentials (SSEPs) from either the intervertebral disc or the ligamentum flavum after epidural stimulation. The site of conduction block identified by abrupt reduction in size of the negative peak was designated as the 0 level with the other levels numbered in order of distance assigning a minus sign caudally.
A single site of focal conduction block was disclosed in 42 patients, 23 (55%) at C3-4, 17 (40%) at C4-5, and two (5%) at C5-6. At these levels (0), the amplitude of the negative component was reduced (p<0.0001) to 29% and the area to 22%, with a concomitant increase (p<0.0001) of the initial positive component to 150% in amplitude and 293% in area as compared to the-2 level which was taken as the baseline (100%).
A high incidence (95%) of focal conduction block at C3-4 or C4-5 with normal conduction at C5-6 and C6-7 characterises cervical spondylotic myelopathy in elderly people. Incremental SSEP studies documenting the site of conduction block will help exclude clinically silent cord compression, directing the surgical intervention to the appropriate level of concern.
在MRI显示存在多节段压迫的情况下，精确确定老年脊髓型颈椎病患者传导阻滞的部位。
44例65岁及以上患者在硬膜外刺激后，对椎间盘或黄韧带进行脊髓体感诱发电位（SSEP）的系列椎间记录。负峰大小突然减小所确定的传导阻滞部位被指定为0水平，其他水平按距离顺序编号，向尾侧方向赋予负号。
42例患者发现单个局灶性传导阻滞部位，C3 - 4水平23例（55%），C4 - 5水平17例（40%），C5 - 6水平2例（5%）。在这些水平（0），负成分的幅度降低（p<0.0001）至29%，面积降低至22%，与之相比，初始正成分的幅度增加（p<0.0001）至150%，面积增加至293%，以 - 2水平作为基线（100%）。
C3 - 4或C4 - 5水平局灶性传导阻滞发生率高（95%），C5 - 6和C6 - 7水平传导正常是老年脊髓型颈椎病的特征。记录传导阻滞部位的递增SSEP研究将有助于排除临床无症状的脊髓压迫，指导手术干预至适当的关注水平。
