Spinal cord findings in cervical spondylotic myelopathy: A morphometric analysis

Abstract

Morphometric analyses and pathological studies were carried out on spinal cords from seven cases (aged 71–88 years) with cervical spondylotic myelopathy (CSM), which were taken from cadaver specimens for anatomical dissection. The transverse sections of spinal cord specimens embedded in celloidin were stained with the luxol fast blue‐periodic acid‐Schiff‐hematoxylin or the Klüver‐Barrera methods. The measured items were flatness ration, and areas of cross‐section, gray matter, and posterior funiculus at C2 to T1, and L1 levels. The measurements were carried out with the use of a combination of an electronic optical planimeter and a computer. The results showed that: (i) the most vulnerable segments in the cases of compression myelopathy were at C4‐C6; (ii) the cross‐sectional areas of the spinal cord with CSM were significantly smaller at C4‐C6 levels compared with a normal group; (iii) the flatness ratio in CSM was obviously reduced at C4‐C6 levels; (iv) the shape of the gray matter in CSM became severely flat, and the areas were significantly smaller at C4‐C8, and L1 levels. The following findings were also observed: neuronal loss in the anterior horn; the formation of slit‐like cavities in the gray matter (lateral part of the intermediate substance) at the compressed levels; and many amyloid bodies deposited in the posterior funiculus, and/or lateral funiculus. This finding had never been noted before in relation to CSM. There are three types of compression of the cervical spinal cord: whole ventral, ventromedian, and ventrolateral.