149 Role of DTI in Predicting Outcome in Cervical Spondylotic Myelopathy

INTRODUCTION: Cervical spondylotic myelopathy (CSM) is the most common cause of myelopathy in adults. Surgical decompression is commonly used to treat these patients. METHODS: We conducted a prospective observational study in which patients with CSM admitted for cervical decompression. DTI and T1 post-contrast images were acquired along with the routine MRI sequences. Fractional anisotropy (FA) value and Apparent Diffusion Coefficient (ADC) value were calculated at the level of maximal cord compression on DTI images. RESULTS: A total of 28 patients with CSM were included in the study according to inclusion criteria. The mean FA value was 0.34 ± 0.11 (range - 0.189 to 0.592). There was no correlation between the FA and ADC value and the anteroposterior diameter of the cervical canal at that level. The FA and ADC values correlated with mJOA score at all time periods (preoperative and postoperative). The FA value did not correlate with the preoperative NDI score. However, there was a negative correlation with NDI score at all time periods following surgery. The FA and ADC value correlated with the percent change in each score i.e. mJOA, NDI, VAS and AMS at all time periods. Nine (32.1%) patients had contrast enhancement of the cord at the level of maximal compression preoperatively. Of the 9 patients, 5 patients underwent contrast MRI after 3 months of surgery and all had resolution of cord enhancement. CONCLUSIONS: We observed significant correlation between FA and ADC value with the surgical outcome, as assessed by mJOA and AMS score. There was also significant correlation between FA value and NDI score at 3 months, 6 months and 1 year post surgery.