Title : Placement of reference electrode position in motor nerve conduction study of ulnar nerve
Abstract:
Background: Ulnar nerve is the second most common entrapment neuropathy in the hand at the wrist and at across elbow. There are various techniques have been developed to diagnosed the entrapment. Ulnar nerve supply to wrist at the two main muscles First Dorsal Interosseous (FDI) and Abductor Digiti Minimi (ADM). Many research shows that FDI muscle is use to diagnose an early entrapment across elbow. Recording from FDI muscles, there is an issue in placing the reference electrode placement due to its positive deflection.
The aim of this research to identify which is the best position to place the reference electrode in FDI muscles.
Method: A total of 46 hands were included in this study. Data was collected based on the extensive and detailed description mentioned in different research papers. The tests were performed by a qualified clinical physiologist (Neurophysiology) using a Keypoint 9033A07 machine, used in line with departmental protocol (Ulnar nerve screening protocol1.1, 2020). All data was recorded numerically to ensure methodological reliability.
Result: Out of 46 hands tested for the nerve conduction study (NCS) by placing reference electrode in three different places i.e. tendon of the FDI muscles at the base of digit II, over the thumb and tendon of ADM muscles at the base of digit V. Tendon of the FDI muscles at the base of digit II shows positive deflection in all hands with amplitude rage between 6-15 mV. Over the thumb show the baseline slightly elevated to get accurate distal motor latency with amplitude between 5-8mV. And tendon of ADM muscles at the base of digit V shows correct baseline for accurate distal motor latency with the amplitude rage 10-18mV.
Conclusion: This study shows that to record the best and clear response by placing the reference electrode at the tendon of ADM muscles at the base of digit V is more reliable as compare to other two areas.
Audience Take Away Notes:
- It is crucial to place the reference electrode in proper place with the normative data should be collected.
