Effect of spinal cord signal intensity changes on clinical outcome after surgery for cervical spondylotic myelopathy.

Object: The presence of intramedullary T2 high signal intensity changes in patients with cervical spondylotic myelopathy (CSM) indicates the existence of a chronic spinal cord compressive lesion. However, the prognostic significance of signal intensity changes remains controversial. The purpose of this study was to evaluate the effect of spinal cord T2 signal intensity changes on the outcome after surgery for CSM.

Method: In a prospective study, 64 patients with CSM who underwent surgical treatment between October 2006 and April 2008 using an anterior approach were included. Based on the clinical symptoms and signs present, the severity of neurological deficits of all patients was scored according to a modified Japanese Orthopaedic Association scale score for CSM just before the surgery and at 6 months follow-up. Recovery rates were calculated at 6 months.

Results: There were 22 patients who did not have spinal cord intensity changes on MR imaging and 44 who demonstrated high-intensity signal changes on T2-weighted images (focal or segmental). No statistically significant differences were found in recovery rates between cases with T2 signal intensity changes and those with no signal intensity changes. However, the postoperative modified Japanese Orthopaedic Association scale scores and the recovery rates were much lower in patients with multisegmental signal intensity changes compared with those without these changes or those with focal signal intensity change, and ANOVA demonstrated this difference to be statistically significant (p < 0.05).

Conclusion: Multisegmental spinal cord signal intensity changes on T2-weighted MR imaging are predictors of a poor outcome in terms of functional recovery rate in patients undergoing operations for CSM.