The assessment of neuronal status in normal and cervical spondylotic myelopathy using diffusion tensor imaging.
METHODS
A prospective observational analysis of diffusion tensor imaging (DTI) datametrics collected from control and patients with cervical spondylotic myelopathy (CSM).


OBJECTIVE
The aims were to study the use of DTI in CSM and to probe whether DTI datametrics and tractography will correlate with magnetic resonance imaging and clinical findings.


BACKGROUND
Magnetic resonance imaging is the current "gold standard" in the assessment of cord status in CSM; however, various parameters such as extent of compression and presence of signal intensity changes do not correlate well with clinical status. DTI is a novel investigation tool with proven applications in brain pathologies but is not routinely used in spinal cord evaluation.


METHODS
Patients with CSM (n = 35) who required surgical decompression (mean age = 48 yr) and 40 normal individuals (mean age = 38 yr) were included. Diffusion Tensor Imaging of the cervical spine was obtained using a 1.5T magnetic resonance image. Apparent diffusion coefficient, fractional anisotropy, and eigenvalues (E1, E2, and E3) were obtained at each cervical level. The DTI datametrics of CSM patients were compared with normal volunteers and correlated with individual and grouped Nurick grades, which indicate the neurological status of patients.


RESULTS
There was significant difference in DTI datametrics between patients with myelopathy and control (P < 0.05), with decrease in fractional anisotropy (0.49 ± 0.081 vs. 0.53 ± 0.07) and increase in apparent diffusion coefficient (1.8 ± 0.315 vs. 1.44 ± 0.145) and eigenvalues (E1: 2.82 ± 0.395 vs. 2.37 ± 0.221, E2: 1.64 ± 0.39 vs. 1.18 ± 0.198, E3: 0.956 ± 0.277 vs. 0.76 ± 0.142). There was also a significant difference between increasing grades of myelopathy when individuals were grouped as-control, self-ambulant (Nurick grades 1 and 2), and dependent (Nurick grades 3, 4, and 5).


CONCLUSIONS
The study shows that DTI is a promising and useful investigational tool in evaluation of CSM. There was a significant difference in all DTI values between control and patients with CSM, and there was a significant trend of change in values between control, self-ambulant, and dependent patients. Our results encourage further investigation of this important modality.


METHODS
3.
*Ganga Hospital, Coimbatore, Tamil Nadu, India; and †Ganga Orthopaedic Research and Education Foundation, Tatabad, Coimbatore, Tamil Nadu, India.
S
S
Rajasekaran
Janardhan S
JS
Yerramshetty
Vishnuprasath S
VS
Chittode
Rishi M
RM
Kanna
Gopalakrishnan
G
Balamurali
Ajoy Prasad
AP
Shetty
D000328:Adult; D016880:Anisotropy; D002574:Cervical Vertebrae / Q000473:pathology* / Q000601:surgery; D019299:Decompression, Surgical; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D013118:Spinal Cord Diseases / Q000473:pathology* / Q000601:surgery; D055009:Spondylosis / Q000473:pathology* / Q000601:surgery