Incidence of upper cervical spondylotic myelopathy is quite rare. This is to analyse clinically and roentgenographically 10 cases with C3-4 cervical spondylotic myelopathy in our series, and to discuss the mechanism of occurrence of this disorder.
There are 8 males and 2 females, ranging in age from 29 to 63 years (average 46.9-year-old). In general, early diagnosis and treatment was made due to prominent and characteristic symptoms and signs.
Queckenstedt' s test in CSF examination showed high rate of positive findings and myelograms confirmed the level of this disorder.
X-ray findings revealed that there existed developmental canal stenosis of the cervical spine, and the canal was the most stenotic at the level of C3 and C4. Disc narrowing and retrolisthesis were also found at the level of C3-4. One of the characteristic findings was steep inclination of the facet joints at the level of C2-3 and C3-4.
Through this study the mechanism of occurrence of CSM at the level of C3-4, which is quite rare, is suggested to be that on the basis of developmental canal stenosis, especially at C3 and C4, the spinal cord is compressed by degenerative changes of the level of C3-4 such as disc narrowing and retrolisthesis, and that the steep inclination of the facet joints may be one of the factors causing disc degeneration.
