| Myelopathy due to chronic compression of the spinal cord is often encountered, the most common cases is cervical spondylotic myelopathy(CSM). cervical spondylotic myelopathyis reported 40 years ago, nevertheless, study on CSM is limited to analysis of clinical data and observation of autopsy. Much to study on its pathophysiology and provide more comprehension. Establishing a stable, simple and easy model is very significance. However, material of compression is embedded through anterior approach formerly, and observes chronic compressing cervical cord statistically, difficult to mimic pathophysiologyof progressive compression. With the result of repeated anterior surgery, surgery is very difficult , complicated and the animal is very easy to death, and so, an ideal experimental methods is deficit; the cervical cord circulation of the canine which often acts as the experimental animal is different from human's, thus study on microcirculation change is unreasonable for its actual role in pathomechanism of CSM. For this reason, a simple double-catheter which is made of medical elastic plastics is designed. At the same time, a serial of caudal propeller is made whose step is 0.5mm.lt is applied in the experiment to induce chronic cord compression, and the result is very significance. By segmental ligature of the canine vertebral artery, the segmental radicular artery system is closed ,and cord circulation system of humans is mimic. By combination of the two experiments, and by behavior, electrophysiolgical, image and histological observation, an ideal model is setup which may ideally dupilicate cervical spondylotic myelopathy. The results is arranged. 1. Experimental Chronic Cervical Cord Compression by Double-catheter Method Self-made elastic plastic double-catheter was implanted in canine vertebral body upper and medial by anterior approach. The cord was chronic compressed by slow propelling the inner catheter. lower limb dysfunction of the canine, prologation of latency of SEP, cervical cord transformation from the ventral compression in MRI image is observed. histological examination show loss of large motor neurons, necrosis;axonal degeneration and demyelination within the white matter .pathology change is coincidence of the character of cord chronic compression. The method to hronic compress cervical cord by double-catheter have serveral advantages: operation is simple,easy and safe;the catheter is cheap;ideally duplicate the point compression mechanism of CSM,which is different fronm the former method by 5 segmental stenosis of vertebral canal.. 2. Study on effects of segemental ligature of vertebral artery upon canine central nervous system. 2.lVertebral artery of the canine were ligated at C4,C5 segment., and observation of behavior electrophysiological, MRI and MRA image ,neuoral histological is obtained. And segmental spinal cord blood flow is quantitive analyzed. After segmental ligature of vertebral artery, in cases of the first day, mild deflation of neurons is observed, others is normal. the circulation is compensated after 7days.Autopsy shows the C45 segmental radicular artery is occluded. The character of the canine cord circulation which is doubly supported by anterior spinal artery and radicular artery is altered. .The new circulation system is more likely to human s. 2.2Posterior and inferior lobe of cerebellum is ex...
|
PDF Full Text Request