Introduction: Although cervical spondylotic myelopathy/CSM is the most common cause of spinal cord dysfunction in adults, a reliable noninvasive biomarker of disease severity and progression is lacking. Diffusion tensor imaging (DTI) measures water diffusion and shows changes in spinal cord microstructure. While studies in spinal cord injury have shown DTI changes distant to the injury, this has not been studied in CSM.
Methods: We performed a prospective cohort study of CSM and normal subjects, excluding patients who could not tolerate a MRI; who had prior cervical surgery or who had nondegenerative/other neuromuscular conditions. DTI was obtained in the internal capsule, C1-2, the level of worst compression in CSM/C4-7 in normals, and T6, and compared using Student's t-test and logistic regression.
Results: 51 subjects were enrolled, of whom 29 had CSM. CSM and normals were similar in age and sex. CSM subjects reported moderate disability (mean mJOA 13). Fractional anisotropy (FA) was significantly lower in CSM subjects at C1-2, level of worst compression, and T6. After adjusting for age, DTI FA was a significant predictor of CSM versus normal at the level of worst compression and T6.
Conclusions: DTI FA is significantly lower in CSM versus normals at the level of worst compression, C1-2, and T6, suggesting CSM subjects have microstructural changes throughout the cord. DTI has great potential as a noninvasive imaging biomarker that may provide a feasible and efficient way to monitor patients and treatment efficacy, even with spinal implants.
Patient Care: This imaging research works to establish an objective biomarker with which to track the severity of cervical spondylotic myelopathy, the most common cause of spinal cord dysfunction in adults.
Learning Objectives: By the conclusion of this session, participants should be able to:
1. To understand the nature and role of DTI in spinal cord imaging
2. To pinpoint the areas of microstructural change in CSM, as shown by DTI
3. To understand the importance of DTI as a noninvasive biomarker