[en] OBJECTIVE: To add objective measurements of the characteristics of evoked injury potentials (EIP) and their relations to clinical severity in dogs with thoracolumbar spinal cord damage. ANIMALS: 25 dogs with naturally acquired spinal cord compression attributable to disk extrusion or vertebral fracture at the level of the thoracolumbar junction and with various degrees of paresis/paralysis. PROCEDURE: Spinal cord potentials evoked by tibial nerve stimulation were recorded every 5 to 10 mm at the lamina level in the vicinity of the cord compression. This allowed an EIP to be recorded even in the least handicapped dogs. A computer model yielded information about the waveform changes of the EIP in the vicinity of conduction blocks. RESULTS: The EIP waveform changed from biphasic to monophasic a short distance caudad to the location of spinal cord compression. Location of a maximal conduction block was measured in relation to position of the electrodes recording this waveform change. The distance between the assumed conduction block and the actual spinal cord compression was larger in the most affected dogs. The amplitude of the EIP was not related to severity of the clinical picture; however, the proximity of the recording electrode to the spine influenced the amplitude and the waveform of the EIP. CONCLUSION AND CLINICAL RELEVANCE: Change in the EIP waveform from biphasic to monophasic makes it possible to estimate the conduction block location along the spinal cord. A large distance between the assumed conduction block and site of actual cord compression could be an objective argument to confirm severity of a lesion.
Disciplines :
Veterinary medicine & animal health
Author, co-author :
Poncelet, Luc
Michaux, Charles ; Université de Liège - ULiège > Département de productions animales > Biostatistique, économie, sélection animale
Grauwels, Magda ; Université de Liège - ULiège > Département clinique des animaux de compagnie et des équidés > Département clinique des animaux de compagnie et des équidés
Language :
English
Title :
Study of Spinal Cord Evoked Injury Potential by Use of Computer Modeling and in Dogs with Naturally Acquired Thoracolumbar Spinal Cord Compression
Publication date :
March 1998
Journal title :
American Journal of Veterinary Research
ISSN :
0002-9645
eISSN :
1943-5681
Publisher :
American Veterinary Medical Association, Schaumburg, United States - Illinois
Priester WA. Canine intervertebreal disease: occurrence by age, breed and sex among 8117 cases. Theriogenology 1976;6:293-303.
Shores A. Spinal trauma. Vet Clin North Am Small Anim Pract 1992;22:859-870.
Poncelet L, Michaux C, Balligand M. Somatosensory potentials in dogs suffering naturally acquired thoracolumbar spinal cord disease. Am J Vet Res 1993;54:1935-1940.
Cracco RQ, Evans B. Spinal evoked potential in the cat: effect of asphyxia, strychnine, cord section and compression. Electroencephalogr Clin Neurophys 1978;44:187-201.
Schramm J, Shigeno T, Brock M. Clinical signs and evoked response alterations associated with chronic experimental cord compression. J Neurosurg 1983;58:734-741.
Schramm J, Kraus R, Shigeno T, et al. Experimental investigation on the spinal cord evoked injury potential. J Neurosurg 1983;59:485-492.
Whittle IR, Johnston IH, Besser M. Recording of spinal somatosensory potentials for intraoperative spinal cord monitoring. J Neurosurg 1986;64:601-612.
Shinomia K, Furuya K, Sato R, et al. Electrophysiological diagnosis of cervical OPLL myelopathy using evoked spinal cord potentials. Spine 1988;13:1225-1233.
Satomi K, Okuma T, Kenmotsu K, et al. Level diagnosis of cervical myelopathy using evoked spinal cord potentials. Spine 1988; 13:1217-1224.
Katayama Y, Tsubokawa T, Yamamoto T, et al. Preoperative determination of the level of spinal cord lesions from the killed end potential. Surg Neurol 1988;29:91-94.
Kikuchi Y, Baba H, Kawahara N, et al. Experience of diagnosis of thoracic myelopathy using spinal cord evoked potentials. In: Shimoji K, Kurokawa T, Tamaki T, et al, eds. Spinal cord monitoring and electrodiagnosis. Berlin: Springer-Verlag, 1991;461-471.
Oshima Y, Harata S, Ueyama K, et al. Level diagnosis using spinal cord evoked potentials in cervical myelopathy. In: Shimoji K, Kurokawa T, Tamaki T, et al, eds. Spinal cord monitoring and electrodiagnosis. Berlin: Springer-Verlag, 1991;454-460.
Holliday TA, Weldon NE, Ealand BJ. Percutaneous recording of evoked spinal cord potentials of dogs. Am J Vet Res 1979;40: 326-333.
Yates BJ, Thompson FJ, Mickle JP. Origin and properties of spinal cord field potentials. Neurosurgery 1982;11:439-450.
Poncelet L, Delauche A, Vinals C, et al. Effect of bilateral tibial nerve stimulation on the spinal evoked potential in dogs. Am J Vet Res 1992;53:1305-1308.
Ealand Snyder BG, Holliday TA. Pathways of ascending evoked potentials of dogs. Electroencephogr Clin Neurophys 1984;58: 140-154.
Brown BH. Theoretical and experimental waveform analysis of human compound nerve action potentials using surface electrodes. Med Biol Engng 1986;6:375-386.
Shores A, Redding RW, Knecht CD. Spinal-evoked potentials in dogs with acute compressive thoracolumbar spinal cord disease. Am J Vet Res 1987;48:1525-1530.
Steiss JE, Wright JC. Maturation of spinal-evoked potentials to tibial and ulnar nerve stimulation in clinically normal dogs. Am J Vet Res 1990;51:1427-1432.
Paintal AS. Conduction in mammalian nerve fibers. In: Desmedt JE, ed. New developments in electromyography and clinical neurophysiology. Vol 2. Basel: S Karger, 1973;19-41.
Prestor B, Zgur T, Dolenc W. Incomplete spinal cord evoked injury potential in man. Spine 1993;18:252-256.
Kierberger RM, Roos CJ, Lubbe AM. The radiological diagnosis of thoracolumbar disc disease in the Daschshund. Vet Radiol Ultrasound 1992;33:255-261.
Prestor B, Zgur T, Dolenc VV. Subpial spinal evoked potentials in patients undergoing junctional dorsal root entry zone coagulation for pain relief. Acta Neurochir (Wien) 1989;101:56-62.
Sarnowsky RJ, Cracco RQ, Vogel HB, et al. Spinal evoked response in the cat. J Neurosurg 1975;43:329-336.
