Development of a motor and somatosensory evoked potentials-guided spinal cord Injury model in non-human primates.

Background Nonhuman primates (NHP) may provide the most adequate (in terms of neuroanatomy and neurophysiology) model of spinal cord injury (SCI) for testing regenerative therapies, but bioethical considerations exclude their use in severe SCI. New Method A reproducible model of SCI at the lower thoracic level has been developed in Rhesus macaques. The model comprises surgical resection of 25% of the spinal cord in the projection of the dorsal funiculus and dorsolateral corticospinal pathways, controlled via registration of intraoperative evoked potentials (EPs). The animals were evaluated using the modified Hindlimb score, MRI, SSEP, and MEP over a time period of 8-12 weeks post-SCI, followed by histological examination. Results Complete disappearance of intraoperative EPs from distal hindlimb muscles without restoration within two weeks post-SCI was an indicator for irreversible disruption of the abovementioned pathways. As a result, controlled damage to the spinal cord was achieved in three NHPs, clinically manifested as irreversible lower monoplegia. No significant functional restoration was observed in these NHPs up to 12 weeks post-SCI. Demyelination of the damaged ascending tracts was detected. Disturbances in pelvic organ function were not observed in all animals. Comparison with existing methods The new method of EPs-guided SCI allows a more controlled and irreversible damage to the spinal cord compared with contusion and other transection approaches. Conclusions This method to induce complete SCI in NHP is well tolerated, reproducible and ethically acceptable: these are valuable attributes in a preclinical model that will hopefully help advance testing of new regenerative therapies in SCI.

[Vertebroplasty in the treatment of spinal diseases]. / Vertebroplastika pri lechenii zabolevanii pozvonochnika.

The results of surgical treatment by vertebroplasty are analyzed in 28 patients with different spinal diseases. A procedure for percutaneous vertebroplasty with polymethyl methacarylate is presented. This miniinvasive method has been shown to be highly effective in treating vertebral hemangiomas, osteoporotic compression fractures, and vertebral metastases and in strengthening the anterior vertebral column as compared with anterior spondylosis in open surgical operations.

[Posterio-median approach in ventral tumor compression of the spinal cord]. / Zadnesredinnyi dostup pri ventral'noi opukholevoi kompressii spinnogo mozga.

The paper describes two types of resection of primary and metastatic spinal tumors via a posterolateral approach: by curettage and en-block resection. The outcomes of treatment in 15 patients operated on by curettage and 2 patients undergone en-block resection are analyzed. Postoperative pain relief was noted in 100% of the patients. Six (55%) patients who had not been able to move became outpatient after surgery. There was a neurological improvement in 5 (29%) patients, i.e. they were at a higher stage by the Frankel scale. The above results show that removal of spinal tumors via posteriomedian access with lateral extension by curettage or en-block resection might be effective in surgically treating this pathology. Choice of a type of surgery (carcinological or palliative) primarily depends on the histological nature of a tumor, on the degree of neurological deterioration, on the extent and site of a tumorous process, and on the expected survival of a patient.