The Prediction of Neurological Prognosis for Cervical Spondylotic Myelopathy Using Diffusion Tensor Imaging

Abstract

Objective: Although cervical spondylotic myelopathy (CSM) can be easily diagnosed using magnetic resonance imaging (MRI), prediction of surgical effect using preoperative radiological examinations remains difficult. In previous studies, it was reported that diffusion tensor imaging (DTI) may be used for the prediction of surgical effect; however, these studies did not consider the influences of spinal cord compression even though the values of DTI indexes can be distorted by compressive lesions in patients with CSM. Therefore, it is uncertain whether preoperative DTI indexes can actually predict the surgical effect. The aim of this study was to investigate DTI metrics that are hardly affected by spinal cord compression and can accurately predict neurological status after decompressive surgery.Methods: Twenty-one patients with CSM who underwent surgery and 10 healthy volunteers were enrolled in this study. The subjects underwent cervical MRI, and values of DTI indexes including axial diffusivity (AD), radial diffusivity (RD), apparent diffusion coefficient (ADC), and fractional anisotropy (FA) were recorded at each intervertebral level. Further, the Japanese Orthopaedic Association (JOA) score of each patient with CSM was recorded before and after surgery for neurological status evaluation. Preoperative and postoperative values of DTI indexes were compared, and correlations between preoperative DTI parameters and postoperative neurological recovery were assessed.Results: After surgery, the lesion-adjacent (LA) ratios of RD and ADC increased (p = 0.04 and p = 0.062, respectively), while the LA ratio of FA decreased (p = 0.075). In contrast, the LA ratio of AD hardly changed. A negative correlation was observed between preoperative LA ratio of AD and JOA recovery rate 6 months after surgery (r = -0.379, p = 0.091). Based on preoperative LA ratio of AD, the patients were divided into a low AD group and a high AD group, and JOA recovery rate 6 months after surgery was found to be higher in the low AD group than in the high AD group (p = 0.024).Conclusion: In patients with CSM, preoperative LA ratio of AD is seldom affected by spinal cord compression, and it negatively correlates with JOA recovery rate 6 months after surgery.

Correlation Between Pre-Operative Diffusion Tensor Imaging Indices and Post-Operative Outcome in Degenerative Cervical Myelopathy: A Systematic Review and Meta-Analysis

“…In the meta-analysis examining the correlation between recovery rate and ADC, data were consolidated from 4 studies ( Figure 6 ). 27 , 29 , 33 , 36 The random effects model, which collates findings from 204 participants, illustrates a correlation coefficient of −.47. This correlation is supported by a 95% CI that spans from −.60 to −.33, indicating a significant negative correlation.…”

“…In the meta-analysis evaluating the correlation between AD and recovery rate, data has been synthesized from 4 studies ( Figure 7 ). 13 , 29 , 33 , 36 The overall random effects model, comprising findings from 232 participants, demonstrates a correlation coefficient of −.10 with a 95% CI spanning from −.31 to .12, suggesting no significant correlation. Upon analyzing the data stratified by age, the subgroup with participants aged 65 and above produced a correlation of −.05 with a 95% CI of −.27 to .18, reiterating the absence of a significant correlation.…”

“…Seventeen studies were included in this systematic review, of these 5 studies were conducted in United States of America, 12 , 16 , 26 , 28 , 34 9 in Asia, 13 , 22 - 24 , 27 , 29 , 31 , 33 , 35 , 36 2 in India 25 , 30 and 1 in Switzerland. 32 The total number of patients were 653 with sample size ranging from 15 31 to 95.…”

“…Nurick scale in 2 studies, 12 , 25 delta JOA in 2 studies, 24 , 31 and JOA, 29 NDI, 12 delta NDI, 26 SF36 12 and delta SF36 26 each were assessed in specific included studies. For correlation analysis between DTI parameters and outcomes, 8 studies utilized Pearson correlation coefficient, 25 - 27 , 32 - 36 6 studies Spearman correlation coefficient 12 , 13 , 22 - 24 , 31 and 4 studies Regression analysis. 16 , 28 - 30 …”

“…8 studies investigated the correlation between FA and recovery rate. 13 , 23 , 24 , 27 , 31 , 33 , 35 , 36 In the meta-analysis exploring the relationship between FA and recovery rate, a discernible correlation emerges. The comprehensive random effects model, consolidating data from 303 participants across various studies, pinpointed a correlation of .22, with a 95% CI from .00 to .42, indicating a positive marginally significant correlation ( Figure 4 ).…”