Table 1 Electrodiagnostic routine and provocative comparison techniques performed in the study
Technique | Recording site | Stimulation site | Abnormal cut-off |
|---|---|---|---|
MMCS | - G1 was placed over the APB muscle belly and G2 was placed over the first MCP. - DL, Amp, and CV were analyzed. | - Proximal to the wrist between the FCR and PL tendons 7cm from G1 - At the antecubital fossa over the brachial artery pulse. | DL ≥ 4.4ms |
MSCS | - From index finger: Using antidromic procedure, ring electrodes with G1 placed over the MCP joint and G2 was placed 3–4 cm distally over the distal IPJ. - Distal peak latency, peak to peak amplitude and CV was analyzed. | Wrist: middle of the wrist between the tendons of FCR and PL at 13 cm distance from the recording electrodes | PL ≥ 3.7ms. |
Median versus radial sensory study (MVR) | - From the thumb: Using antidromic procedure, ring electrodes with G1 was placed over the MCP joint and G2 placed over the distal IPJ. - The difference between median and radial latencies was analyzed. | - MN at the wrist: 10 cm from G1, middle of the wrist between FCR and PL tendons. - RN at the wrist: 10 cm from G1, lateral forearm, over radial bone | ≥ 0.4 ms [13] |
Median versus ulnar sensory study (MVU) | - From ring finger: Using antidromic procedure, ring electrodes with G1 was placed over the MCP joint and G2 placed 3–4 cm distally over the distal IPJ. - The difference between median and ulnar latencies was analyzed. | - MN at the wrist: 14 cm from G1, middle of the wrist between FCR and PL tendons. - UN at the wrist: 14 cm from G1, Medial wrist, adjacent to the FCU tendon | ≥ 0.5ms [10] |
Median versus ulnar lumbrical- interossei motor study (LM-IN) | - G1 was placed slightly lateral to the midpoint of the 3rd metacarpal and G2 was placed over the MCP of the 2nd digit distally. - The difference between the median and ulnar latencies was analyzed. | - MN at the wrist: middle of the wrist between FCR and PL tendons. - UN at the wrist: medial wrist, adjacent to FCU tendon - Distal distance between stimulation site and G1: 8–10 cm (the same distance is used for both nerves) | ≥ 0.5 ms [10] |
Median versus ulnar palmar mixed nerve study (Mix M-U) | - MN at the wrist with G1 placed over the middle of the wrist between FCR and PL tendons and G2 placed 3–4 cm proximally - UN at the wrist with G1 placed over the medial wrist, adjacent to the FCU tendon, and G2 placed 3–4cm proximally - The difference between median and ulnar latencies was analyzed - The application of the test was shown in Fig. 2. | - MN in the palm: 8 cm from the G1 on a line drawn from the median wrist to the web space between the index and middle fingers. - UN in the palm: 8cm from the active recording electrode on a line drawn from the ulnar wrist space between the ring and little fingers | ≥ 0.4ms [13] |