Measurement of the local pressure of the intervertebral foramen and the electrophysiologic values of the spinal nerve roots in the vertebral foramen.
METHODS
The intraoperative findings of the local pressure of the intervertebral foramen and the electrophysiologic values of the spinal nerve roots were evaluated.


OBJECTIVE
To investigate the neurophysiologic changes of the spinal nerve roots in the vertebral foramen.


BACKGROUND
As far as we know, few reports have so far described the neurophysiologic changes of the spinal nerve roots in the vertebral foramen.


METHODS
The local pressure of the intervertebral foramen was continuously measured while the lumbar spine posture was changed in 66 vertebral foramens. In addition, 20 L5 nerve roots were electrophysiologically evaluated using the compound muscle action potentials (CMAPs) from tibialis anterior (TA) muscle after L5 nerve root stimulation.


RESULTS
The local pressure of the intervertebral foramen was significantly increased during lumbar spine extension (P < 0.001); moreover, the latency and amplitude of the CMAPs both significantly deteriorated in line with the increasing local pressure.


CONCLUSIONS
Our findings suggested that a double compression of the nerve root exists in lumbar spinal stenosis with lumbar spine extension, which includes the spinal canal and the vertebral foramen.
Morishita
Yuichiro
Y
Department of Orthopaedic Surgery, Fukuoka University, Fukuoka, Japan. md030019@cis.fukuoka-u.ac.jp
Hida
Shinichi
S
Naito
Masatoshi
M
Arimizu
Jun
J
Matsushima
Ushio
U
Nakamura
Atsuhiko
A
D000200:Action Potentials / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004568:Electrodiagnosis; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000503:physiopathology*; D007405:Intervertebral Disc Displacement / Q000150:complications / Q000503:physiopathology*; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000209:etiology / Q000503:physiopathology; D011187:Posture; D011312:Pressure; D013126:Spinal Nerve Roots / Q000503:physiopathology*; D013130:Spinal Stenosis / Q000150:complications / Q000503:physiopathology*