Chun-Yi Wen1, Jiao-Long Cui1, Kin-Cheung Mak1, Keith D K Luk1, Yong Hu2. 1. Department of Orthopaedics and Traumatology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 12 Sandy Bay Rd, Pokfulam, Hong Kong, China. 2. Department of Orthopaedics and Traumatology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 12 Sandy Bay Rd, Pokfulam, Hong Kong, China. Electronic address: yhud@hku.hk.
Abstract
BACKGROUND AND CONTEXT: Abnormal somatosensory evoked potential (SEP) (ie, prolonged latency) has been associated with poor surgical prognosis of cervical spondylotic myelopathy (CSM). PURPOSE: To further characterize the extent of microstructural damage to the somatosensory tract in CSM patients using diffusion tensor imaging (DTI). STUDY DESIGN/ SETTING: Retrospective study. PATIENT SAMPLE: A total of 40 volunteers (25 healthy subjects and 15 CSM patients). OUTCOME MEASURES: Clinical, electrophysiological, and radiological evaluations were performed using the modified Japanese Orthopedic Association (mJOA) scoring system, SEP, and cord compression ratio in anatomic magnetic resonance (MR) images, respectively. Axial diffusion MR images were taken using a pulsed gradient, spin-echo-echo-planar imaging sequence with a 3-T MR system. The diffusion indices in different regions of the spinal cord were measured. METHODS: Comparison of diffusion indices among healthy and myelopathic spinal cord with intact and impaired SEP responses were performed using one-way analysis of variance. RESULTS: In healthy subjects, fractional anisotropy (FA) values were higher in the dorsal (0.73±0.11) and lateral columns (0.72±0.13) than in the ventral column of white matter (0.58±0.10) (eg, at C4/5) (p<.05). FA was dramatically dropped in the dorsal (0.54±0.16) and lateral columns (0.51±0.13) with little change in the ventral column (0.48±0.15) at the compressive lesions in CSM patients. There were no significant differences in the mJOA scores or cord compression ratios between CSM patients with or without abnormal SEP. However, patients with abnormal SEP showed an FA decrease in the dorsal column cephalic to the lesion (0.56±0.06) (ie, at C1/2, compared with healthy subjects [0.66±0.02]), but the same decrease was not observed for those without a SEP abnormality (0.67±0.02). CONCLUSION: Spinal tracts were not uniformly affected in the myelopathic cervical cord. Changes in diffusion indices could delineate focal or extensive myelopathic lesions in CSM, which could account for abnormal SEP. DTI analysis of spinal tracts might provide additional information not available from conventional diagnostic tools for prognosis of CSM.
BACKGROUND AND CONTEXT: Abnormal somatosensory evoked potential (SEP) (ie, prolonged latency) has been associated with poor surgical prognosis of cervical spondylotic myelopathy (CSM). PURPOSE: To further characterize the extent of microstructural damage to the somatosensory tract in CSM patients using diffusion tensor imaging (DTI). STUDY DESIGN/ SETTING: Retrospective study. PATIENT SAMPLE: A total of 40 volunteers (25 healthy subjects and 15 CSM patients). OUTCOME MEASURES: Clinical, electrophysiological, and radiological evaluations were performed using the modified Japanese Orthopedic Association (mJOA) scoring system, SEP, and cord compression ratio in anatomic magnetic resonance (MR) images, respectively. Axial diffusion MR images were taken using a pulsed gradient, spin-echo-echo-planar imaging sequence with a 3-T MR system. The diffusion indices in different regions of the spinal cord were measured. METHODS: Comparison of diffusion indices among healthy and myelopathic spinal cord with intact and impaired SEP responses were performed using one-way analysis of variance. RESULTS: In healthy subjects, fractional anisotropy (FA) values were higher in the dorsal (0.73±0.11) and lateral columns (0.72±0.13) than in the ventral column of white matter (0.58±0.10) (eg, at C4/5) (p<.05). FA was dramatically dropped in the dorsal (0.54±0.16) and lateral columns (0.51±0.13) with little change in the ventral column (0.48±0.15) at the compressive lesions in CSM patients. There were no significant differences in the mJOA scores or cord compression ratios between CSM patients with or without abnormal SEP. However, patients with abnormal SEP showed an FA decrease in the dorsal column cephalic to the lesion (0.56±0.06) (ie, at C1/2, compared with healthy subjects [0.66±0.02]), but the same decrease was not observed for those without a SEP abnormality (0.67±0.02). CONCLUSION: Spinal tracts were not uniformly affected in the myelopathic cervical cord. Changes in diffusion indices could delineate focal or extensive myelopathic lesions in CSM, which could account for abnormal SEP. DTI analysis of spinal tracts might provide additional information not available from conventional diagnostic tools for prognosis of CSM.
Authors: Allan R Martin; Izabela Aleksanderek; Julien Cohen-Adad; Zenovia Tarmohamed; Lindsay Tetreault; Nathaniel Smith; David W Cadotte; Adrian Crawley; Howard Ginsberg; David J Mikulis; Michael G Fehlings Journal: Neuroimage Clin Date: 2015-12-04 Impact factor: 4.881
Authors: Jan Valošek; Petr Bednařík; Miloš Keřkovský; Petr Hluštík; Josef Bednařík; Alena Svatkova Journal: J Clin Med Date: 2022-04-20 Impact factor: 4.964
Authors: Benjamin S Hopkins; Kenneth A Weber; Michael Brendan Cloney; Monica Paliwal; Todd B Parrish; Zachary A Smith Journal: Spine (Phila Pa 1976) Date: 2018-10-15 Impact factor: 3.241