Increased spinal cord movements in cervical spondylotic myelopathy.
BACKGROUND
Magnetic resonance imaging (MRI) is a very useful diagnostic test for cervical spondylotic myelopathy (CSM) because it can identify degenerative changes within the spinal cord (SC), disclose the extent, localization, and the kind of SC compression, and help rule out other SC disorders. However, the relationships between changes in cerebrospinal fluid (CSF) flow, cord motion, the extent and severity of spinal canal stenosis, and the development of CSM symptoms are not well understood.


OBJECTIVE
To evaluate if changes in the velocity of CSF and SC movements provide additional insight into the pathophysiological mechanisms underlying CSM beyond MRI observations of cord compression.


METHODS
Prospective radiologic study of recruited patients.


METHODS
Thirteen CSM subjects and 15 age and gender matched controls.


METHODS
Magnetic resonance imaging measures included CSF and SC movement. Cervical cord condition was assessed by the Japanese Orthopaedic Association (JOA) score, compression ratio (CR), and somatosensory evoked potentials (SSEPs) of the tibial and ulnar nerves.


METHODS
Phase-contrast imaging at the level of stenosis for patients and at C5 for controls and T2-weighted images were compared with clinical findings.


RESULTS
Cerebrospinal fluid velocity was significantly reduced in CSM subjects as compared with controls and was related to cord CR. Changes in CSF velocity and cord compression were not correlated with clinical measures (JOA scores, SSEP) or the presence of T2 hyperintensities. Spinal cord movements, that is, cord displacement and velocity in the craniocaudal axis, were increased in CSM patients. Increased SC movements (ie, total cord displacement) both in the controls and CSM subjects were associated with altered spinal conduction as assessed by SSEP.


CONCLUSIONS
This study revealed rather unexpected increased cord movements in the craniocaudal axis in CSM patients that may contribute to myelopathic deteriorations in combination with spinal canal compression. Understanding the relevance of cord movements with respect to supporting the clinical CSM diagnosis or disease monitoring requires further long-term follow-up studies.
Department of Radiology, 2211 Wesbrook Mall, University of British Columbia, Vancouver, BC, Canada, V6T 2B5. Electronic address: lees@phas.ubc.ca.
Irene M
IM
Vavasour
Department of Physics and Astronomy, 6224 Agricultural Rd, University of British Columbia, Vancouver, BC, Canada, V6T 1Z1.
Sandra M
SM
Meyers
Department of Medicine, 2775 Laurel St, 10th Floor, Vancouver, BC, Canada, V5Z 1M9.
Erin L
EL
MacMillan
Department of Neurosurgery, Sigmund-Freud-Str. 25, Univerity of Bonn, Germany, 53105.
Burkhard
B
Mädler
Department of Radiology, 2211 Wesbrook Mall, University of British Columbia, Vancouver, BC, Canada, V6T 2B5.
David K B
DK
Li
Department of Radiology, 2211 Wesbrook Mall, University of British Columbia, Vancouver, BC, Canada, V6T 2B5; UBC MRI Research Centre, M10 Purdy Pavilion, 2111 Wesbrook Mall, University of British Columbia, Vancouver, BC, Canada, V6T 2B5.
Alexander
A
Rauscher
Department of Radiology, 855 W 12th Ave, Vancouver General Hospital, Vancouver, BC, Canada, V5Z 4E3.
Talia
T
Vertinsky
Department of Radiology, 855 W 12th Ave, Vancouver General Hospital, Vancouver, BC, Canada, V5Z 4E3.
Vic
V
Venu
Department of Radiology, 2211 Wesbrook Mall, University of British Columbia, Vancouver, BC, Canada, V6T 2B5; Department of Physics and Astronomy, 6224 Agricultural Rd, University of British Columbia, Vancouver, BC, Canada, V6T 1Z1.
Alex L
AL
MacKay
Spinal Cord Injury Center, Forchstrasse 340, University of Zurich, CH-8008 Zurich, Switzerland; International Collaboration on Repair Discoveries (ICORD), 818 West 10th Ave, University of British Columbia, Vancouver, BC, Canada, V5Z 1M9.
Armin
A
Curt
D000368:Aged; D002555:Cerebrospinal Fluid / Q000502:physiology*; D066193:Cervical Cord / Q000503:physiopathology*; D002574:Cervical Vertebrae / Q000473:pathology*; D055724:Electrophysiological Phenomena; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009068:Movement; D011446:Prospective Studies; D013117:Spinal Cord Compression / Q000503:physiopathology*; D055009:Spondylosis / Q000503:physiopathology*
Cervical spondylotic myelopathy; Magnetic resonance imaging; Phase contrast; Somatosensory evoked potentials; Spinal cord movement; Stenosis