Abstract
We compared the surgical results for cervical spondylotic myelopathy with MRI abnormalities of multilevel cord compression among 60 patients who had anterior microsurgical decompression followed by fusion at a single most appropriate level and 43 patients who had multilevel laminoplasty.
Multilevel recording of ascending spinal cord evoked potentials after epidural stimulation precisely identified the levels of abnormality during anterior surgery before decompression procedures. The anterior and posterior groups showed no statistical difference in preoperative data including duration of symptoms (5.8 months vs 7.4 months), JOA functional score (8.1 vs 8.4), sagittal diameter of spinal canal (12.5 mm vs 12.5 mm)and the number of cord indentations (3.29 vs 3.14). However, the patients were significantly older in the anterior group than the posterior group (70.1 years vs 65.0 years). The two groups showed a comparable improvement of JOA functional score after surgery (12.8 vs 11.9)with a similar follow-up period (3.02 years vs 3.04 years).
These data suggest that electrophysiological documentation of this condition plays an important role in anterior surgical intervention,particularly in elder patients who tend to have clinically silent cord compression at multiple levels on MRI. Anterior decompression, followed by fusion at a single optimal level, when compared with multilevel laminoplasty, is less invasive with lower incidence of postoperative axial symptoms inherent in posterior surgeries.
