Study of Experimental Cervical Spondylotic Myelopathy

Shinomiya, Kayo; Mutoh, N.; Furuya, K.

doi:10.1097/00007632-199210001-00007

Cited by 34 publications

(23 citation statements)

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“…These investigators, however, did not describe the relationship between compression and neuronal loss. Other experimental work by A1-Mefty et al [1], Hukuda and Wilson [22], Saito et al [39] and Shinomiya et al [42] also suggested neuronal damage at the level of compression with reference to functional compromise. However, we believe that it is essential to quantitate motoneuronal dysfunction relative to the degree of spinal cord deformation and to study topographical changes occurring at the level of compression and at cord segments far from the compression site.…”

Section: Discussionmentioning

confidence: 87%

Three-dimensional topographic analysis of spinal accessory motoneurons under chronic mechanical compression: an experimental study in the mouse

et al. 1997

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We investigated the effect of chronic mechanical compression of the cervical spinal cord on the number of spinal accessory motoneurons in 25 tiptoe-walking Yoshimura mice. The animals had calcified deposits in the atlantoaxial membrane at the C1-C2 vertebral level, compressing the spinal cord posterolaterally. Motoneurons of the spinal accessory nerve between C1 and C5 segments were labelled using wheat germ agglutinin-horseradish peroxidase (WGA-HRP) injected into the sternocleidomastoid muscles. The counted cells were processed into a three-dimensional computer display to analyse the cytoarchitectonic changes caused by external cord compression. The number of WGA-HRP-labelled spinal accessory motoneurons was significantly reduced on the affected side. The number of motoneurons in compromised C2 and C3 cord segments correlated linearly with the extent of mechanical compression, but no such relationship was present on the contralateral side. There was an increase in the number of WGA-HRP-labelled spinal accessory motoneurons in the medial cell pools of the anterior grey horn at a level most rostral to the compression, and in the ventrolateral cell pools at levels immediately rostral to the compression. Our findings suggest that the spinal accessory motoneurons translocate rostral to the area of external compression in order to avoid mechanical injury.

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Section: Discussionmentioning

confidence: 87%

Three-dimensional topographic analysis of spinal accessory motoneurons under chronic mechanical compression: an experimental study in the mouse

et al. 1997

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“…Shinomia et al [35] gradually increased anterior compression using a metal screw, and observed that the single compression group did not show any disturbance of limb function during 50% compression of the spinal canal. Schramm et al [32] gradually increased posterior compression level, and observed motor paralysis of the lower extremities at 66% (mean) of stenosis.…”

Section: Spinal Cord Compression and Appearance Of Paralysismentioning

confidence: 98%

“…To date, chronic compression to the spinal cord has been examined by gradually increasing compression levels using balloon [38] or metal screws [32,35], or in the epidural tumor models [3,11,12,23,24,40]. Speed and degree of compression given by a balloon or metal screws are easily controllable, but additional compression could cause spinal cord injury, which then tends to result in acute spinal cord compression.…”

Section: Previous Spinal Cord Compression Experiments and The Evaluamentioning

confidence: 99%

“…However, these experiments usually utilized the models of acute symptoms produced by weight bearing andlor clamps, and there have been a few studies on chronic compression. Major symptom of cervical spondylotic myelopathy is spinal paralysis which is generated by the osteoarthropathic changes of the spine, and the spine presents such morphological characteristics as cervical disk degeneration, osteophyte formation [1,4,35,37,39,41], hypertrophic yellow ligament [26,29,36], cervical spinal stenosis [8][9][10]27,29,42], and abnormal mobility of the cervical spine [30]. In regard to the generation process of cord symptoms, there have been two major assumptions.…”

Section: Introductionmentioning

confidence: 99%

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A new rabbit model for the study on cervical compressive myelopathy

Kanchiku

Taguchi

Kaneko

et al. 2001

Journal Orthopaedic Research

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Development process and pathology of myelopathy due to chronic spinal cord compression have not been fully elucidated. This study was conducted in order to establish an experimental model which can efficiently produce myelopathy and be useful in the studies on myelopathy due to chronic spinal cord compression. Under electrophysiological monitoring of the spinal cord, anterior compression was produced on C5 using a plastic screw. Two weeks later, a plastic plate was inserted under the C5 arch. For the subsequent 10 months on average, walking pattern and MR images were periodically monitored. Before the sacrifice, electrophysiological test was performed and then histopathological examination was done. Palsy appeared at 5 months on average after the addition of posterior compression. Mean compression ratio of the spinal cord calculated on MR images was 34%. All animals with compression showed a high intramedullary signal intensity, and the mean contrast-to-noise ratio (CNR) in the compressed area was 49%. Electrophysiological test showed a significant decrease in the amplitude of spinal cord evoked potentials (SCEPs) at the given compression level. Histology showed flattening of the anterior horn, disappearance and necrosis of anterior horn cells in the gray matter; and demyelination and axonal degeneration in the white matter. The antero-posterior compression produces the condition of spinal canal stenosis. Repeated antero-posterior compression to the spinal cord is important in establishing myelopathy. The present animal model was evaluated to be useful in the studies on myelopathy.

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“…Animal experiments have demonstrated that multiple compressions of the spinal cord caused more severe deterioration functionally and electrophysiologically as well as histologically than a single compression [18]. Therefore, multiple compressive state of the spinal cord appears to have potent neural vulnerability.…”

Section: Possible Involvement Of Flatness In the Cervical Spinal Cordmentioning

confidence: 99%

Boomerang deformity of cervical spinal cord migrating between split laminae after laminoplasty

Kimura¹,

Gomibuchi

Shimoda

et al. 2000

European Spine Journal

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IntroductionCervical laminoplasty, for which there are three major methods -Z-shaped enlargement [4,11], unilateral enlargement [2,5,8,12,20], and median enlargement [9,15,16] -is a useful method for surgical management of cervical myelopathy due to spinal canal stenosis [2]. Of these, Kurokawa's laminoplasty with median splitting of the spinous processes [15] has become the most widespread method in Japan, because it has certain advantages. The most critical advantage is the maintenance of physiological cervical lordosis through the preservation of the posterior bony architecture. This procedure allows the cervical spinal cord to move posteriorly, and decompresses it by opening the laminae on both sides [15]. Some papers have reported satisfactory clinical outcome without serious operative complications using this procedure and its modification [17,23].However, we have already reported two cases of a curious complication after Kurokawa's laminoplasty [13]. We refer to this complication as a "boomerang sign", as it describes the boomerang shape of the cervical spinal cord caused by migration of the cord between the split laminae following Kurokawa's laminoplasty. The grade of the boomerang deformity progressed following surgery as Abstract Patients with cervical compression myelopathy were studied to elucidate the mechanism underlying boomerang deformity, which results from the migration of the cervical spinal cord between split laminae after laminoplasty with median splitting of the spinous processes (boomerang sign). Thirty-nine cases, comprising 25 patients with cervical spondylotic myelopathy, 8 patients with ossification of the posterior longitudinal ligament, and 6 patients with cervical disc herniation with developmental canal stenosis, were examined. The clinical and radiological findings were retrospectively compared between patients with (B group, 8 cases) and without (C group, 31 cases) boomerang sign. Moderate increase of the grade of this deformity resulted in no clinical recovery, although there was no difference in clinical recovery between the two groups. Most boomerang signs developed at the C4/5 and/or C5/6 level, where maximal posterior movement of the spinal cord was achieved. Widths between lateral hinges and between split laminae in the B group were smaller than in the C group. Flatness of the spinal cord in the B group was more severe than in the C group. In conclusion, the boomerang sign was caused by posterior movement of the spinal cord, narrower enlargement of the spinal canal and flatness of the spinal cord.

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Study of Experimental Cervical Spondylotic Myelopathy

Cited by 34 publications

References 0 publications

Three-dimensional topographic analysis of spinal accessory motoneurons under chronic mechanical compression: an experimental study in the mouse

Three-dimensional topographic analysis of spinal accessory motoneurons under chronic mechanical compression: an experimental study in the mouse

A new rabbit model for the study on cervical compressive myelopathy

Boomerang deformity of cervical spinal cord migrating between split laminae after laminoplasty

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