Comparison of Muscle MEPs From Transcranial Magnetic and Electrical Stimulation and Appearance of Reflexes in Horses.
| Autor: | Journée SL; Equine Diagnostics, Wyns, Netherlands.; Department of Virology, Parasitology and Immunology, Research Group of Comparative Physiology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium., Journée HL; Department of Neurosurgery, University Medical Center Groningen, University of Groningen, Groningen, Netherlands.; Department of Orthopedics, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands.; Department of Orthopedics, University Medical Center Amsterdam, Amsterdam, Netherlands., Berends HI; Department of Orthopedics, University Medical Center Amsterdam, Amsterdam, Netherlands., Reed SM; Rood & Riddle Equine Hospital, Lexington, KY, United States.; M.H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington KY, United States., de Bruijn CM; Wolvega Equine Clinic, Oldeholtpade, Netherlands., Delesalle CJG; Department of Virology, Parasitology and Immunology, Research Group of Comparative Physiology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium. |
|---|---|
| Jazyk: | angličtina |
| Zdroj: | Frontiers in neuroscience [Front Neurosci] 2020 Sep 25; Vol. 14, pp. 570372. Date of Electronic Publication: 2020 Sep 25 (Print Publication: 2020). |
| DOI: | 10.3389/fnins.2020.570372 |
| Abstrakt: | Introduction: Transcranial electrical (TES) and magnetic stimulation (TMS) are both used for assessment of the motor function of the spinal cord in horses. Muscular motor evoked potentials (mMEP) were compared intra-individually for both techniques in five healthy horses. mMEPs were measured twice at increasing stimulation intensity steps over the extensor carpi radialis (ECR), tibialis cranialis (TC), and caninus muscles. Significance was set at p < 0.05. To support the hypothesis that both techniques induce extracranially elicited mMEPs, literature was also reviewed. Results: Both techniques show the presence of late mMEPs below the transcranial threshold appearing as extracranially elicited startle responses. The occurrence of these late mMEPs is especially important for interpretation of TMS tracings when coil misalignment can have an additional influence. Mean transcranial motor latency times (MLT; synaptic delays included) and conduction velocities (CV) of the ECR and TC were significantly different between both techniques: respectively, 4.2 and 5.5 ms (MLT Conclusion: Both intracranial and extracranial mMEPs inevitably carry characteristics of brainstem reflexes. To avoid false interpretations, transcranial mMEPs can be identified by a stepwise latency shortening of 15-20 ms when exceeding the transcranial motor threshold at increasing stimulation intensities. A ring block around the vertex is advised to reduce interference by extracranial mMEPs. mMEPs reflect the functional integrity of the route along the brainstem nuclei, extrapyramidal motor tracts, propriospinal neurons, and motoneurons. The corticospinal tract appears subordinate in horses. TMS and TES are interchangeable for assessing the functional integrity of motor functions of the spinal cord. However, TES reveals significantly shorter MLTs, higher conduction velocities, and better reproducibility. (Copyright © 2020 Journée, Journée, Berends, Reed, de Bruijn and Delesalle.) |
| Databáze: | MEDLINE |
| Externí odkaz: |
|