The prevalence of cervical myelopathy among subjects with narrow cervical spinal canal in a population-based magnetic resonance imaging study: the Wakayama Spine Study.
BACKGROUND
A narrow cervical spinal canal (CSC) is a well-known risk factor for cervical myelopathy (CM). However, no epidemiologic data of the CSC based on a population-based cohort are available.


OBJECTIVE
The purpose of the study was to investigate the age-related differences in CSC diameters on plain radiographs and to examine the associated magnetic resonance imaging (MRI) abnormalities including cervical cord compression and increased signal intensity (ISI) as well as the clinical CM with the narrow CSC.


METHODS
This was a cross-sectional study.


METHODS
Data were obtained from the baseline survey of the Wakayama Spine Study that was performed from 2008 to 2010 in a western part of Japan. Finally, a total of 959 subjects (319 men and 640 women; mean age, 66.4 years) were included.


METHODS
The outcome measures included in the study were the CSC diameter at C5 level on plain radiographs, cervical cord compression and ISI on sagittal T2-weighted MRI, and physical signs related to CM (eg, the Hoffmann reflex, hyperreflexia of the patellar tendon, the Babinski reflex, sensory and motor function, and bowel/bladder symptoms).


METHODS
The age-related differences of CSC diameters in men and women were investigated by descriptive statistics. The prevalence of MRI abnormalities and clinical CM was compared among the groups divided by the CSC diameter (less than 13, 13-15, and 15 mm or more). In addition, a logistic regression analysis was performed to determine the association of the CSC diameter with cervical cord compression/clinical CM after overall adjustment for age, sex, and body mass index.


RESULTS
The CSC diameter was narrower with increasing age in both men and women. The prevalence of cervical cord compression, ISI, and the clinical CM was significantly higher in the narrower CSC group. The prevalence of cervical cord compression, ISI, and CM among subjects with CSC diameter less than 13 mm was 38.0%, 5.4%, and 10.1%, respectively. In the logistic model, the CSC diameter was a significant predictive factor for the clinical CM (p<.0001).


CONCLUSIONS
This study firstly confirmed the age-related differences in CSC diameters and the significant association of the narrow CSC diameter with CM in a population-based cohort.
Department of Orthopaedic Surgery, Wakayama Medical University, 811-1, Kimiidera, Wakayama City, 641-8510, Japan.
Keiji
K
Nagata
Department of Joint Disease Research, 22nd Century Medical and Research Center, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8654, Japan.
Noriko
N
Yoshimura
Department of Orthopaedic Surgery, Wakayama Medical University, 811-1, Kimiidera, Wakayama City, 641-8510, Japan. Electronic address: hashizum@wakayama-med.ac.jp.
Hiroshi
H
Hashizume
Department of Clinical Motor System Medicine, 22nd Century Medical & Research Center, Faculty of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8654, Japan.
Shigeyuki
S
Muraki
Department of Orthopaedic Surgery, Wakayama Medical University, 811-1, Kimiidera, Wakayama City, 641-8510, Japan.
Yuyu
Y
Ishimoto
Department of Orthopaedic Surgery, Wakayama Medical University, 811-1, Kimiidera, Wakayama City, 641-8510, Japan.
Hiroshi
H
Yamada
Department of Orthopaedic Surgery, Wakayama Medical University, 811-1, Kimiidera, Wakayama City, 641-8510, Japan.
Noboru
N
Takiguchi
Department of Orthopaedic Surgery, Wakayama Medical University, 811-1, Kimiidera, Wakayama City, 641-8510, Japan.
Yukihiro
Y
Nakagawa
Department of Orthopaedic Surgery, Wakayama Medical University, 811-1, Kimiidera, Wakayama City, 641-8510, Japan.
Akihito
A
Minamide
Department of Joint Disease Research, 22nd Century Medical and Research Center, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8654, Japan.
Hiroyuki
H
Oka
Japan Community Health Care Organization Tokyo Shinjuku Medical Center, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan.
Hiroshi
H
Kawaguchi
Rehabilitation Services Bureau, National Rehabilitation Center for Persons with Disabilities, 1, Namiki 4-chome, Tokorozawa City, Saitama Prefecture 359-8555, Japan.
Kozo
K
Nakamura
Department of Clinical Motor System Medicine, 22nd Century Medical & Research Center, Faculty of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8654, Japan.
Toru
T
Akune
Department of Orthopaedic Surgery, Wakayama Medical University, 811-1, Kimiidera, Wakayama City, 641-8510, Japan.
Munehito
M
Yoshida
D000368:Aged; D066193:Cervical Cord / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007564:Japan; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D013115:Spinal Canal / Q000473:pathology*; D013118:Spinal Cord Diseases / Q000175:diagnosis / Q000453:epidemiology*; D013130:Spinal Stenosis / Q000175:diagnosis / Q000453:epidemiology*
Cervical myelopathy; Cervical spine; Epidemiology; Magnetic resonance imaging; Population-based cohort; Spinal canal stenosis