Magnetic Motor Evoked Potential Recording in Horses Using Intramuscular Needle Electrodes and Surface Electrodes.

The research investigates the feasibility and effectiveness of using surface electrodes, instead of intramuscular needle electrodes, for recording motor evoked potential (MEP) in horses. The findings suggest that surface electrode recordings are compatible and well-tolerated in horses, and show good agreement and repeatability for motor latency times (MLTs), while the results for amplitude measurements were less consistent due to large variations between tests.

Objective and Methodology of the Study

• The study was designed to evaluate the practicality of surface electrodes in recording MEPs in horses, and to compare the results with conventional intramuscular needle electrode recordings. It specifically investigates the repeatability of MLTs and amplitude measurements in both methods.
• The study involved tranascranial MEP recordings on ten sedated warmblood horses using both the traditional needle electrodes and the proposed surface electrodes.

Results of the Study

• The results showed mean MLTs for the thoracic limbs were almost identical for both needle and surface electrode recording; and similarly close results were observed for the pelvic limbs. This indicates that surface electrodes provide comparable MLT readings to needle electrodes.
• The amplitude values for both electrodes also do not vary much for both the thoracic and pelvic limbs. However, the study found inconsistencies in the repeatability and agreement of the amplitude measurements across both types of recordings.

Conclusion

• The study concludes that surface electrodes can indeed be used for recording MEPs in horses, and they provide repeatable and analogous results to needle electrodes in relation to MLTs. This makes them an attractive, preferable alternative due to the painlessness and ease of placement as compared to the intramuscular needle electrodes.
• However, the study also finds that the of amplitude measurements between surface and needle electrodes had large inter-test variations, which warrants further investigation before a conclusive claim can be made about their consistency and repeatability.