Transcranial magnetic stimulation screening for cord compression in cervical spondylosis.
OBJECTIVE
Cervical spondylosis (CS) often results in various degrees of cord compression, which can be evaluated functionally with transcranial magnetic stimulation (TMS). We investigate the use of TMS as a screening tool for myelopathy in CS.


METHODS
We prospectively studied 231 patients classified into Groups 1 to 4 based on MRI grading of severity of cord compromise. TMS elicited central motor conduction times and motor evoked potential (MEP) amplitudes in all 4 limbs. The results were compared with those from 45 healthy controls.


RESULTS
TMS showed 98% sensitivity and 98% specificity for cord abnormality using MRI as reference standard.


CONCLUSIONS
MEP abnormalities are useful for electrophysiological evaluation of cord compression in CS. While TMS is not a substitute for MRI, it is of value as a rapid, inexpensive and non-invasive technique for screening patients before MRI studies.
Lo
Y L
YL
Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Singapore 169608, Singapore. gnrlyl@sgh.com.sg
Chan
L L
LL
Lim
W
W
Tan
S B
SB
Tan
C T
CT
Chen
J L T
JL
Fook-Chong
S
S
Ratnagopal
P
P
D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000473:pathology / Q000503:physiopathology*; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011712:Pyramidal Tracts / Q000293:injuries / Q000503:physiopathology; D011843:Radiculopathy / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D013116:Spinal Cord / Q000473:pathology / Q000503:physiopathology; D013117:Spinal Cord Compression / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D013128:Spinal Osteophytosis / Q000150:complications* / Q000473:pathology / Q000503:physiopathology; D050781:Transcranial Magnetic Stimulation / Q000379:methods*