Comparing distal and proximal techniques of saphenous nerve conduction study in healthy subjects

For comparing distal and proximal techniques. To obtain saphenous nerve sensory response, 102 healthy subjects with mean age 43.1 years and mean Body Mass Index (BMI) 25.3 were studied. Both techniques performed by using surface electrodes. In distal technique recording site was anterior to medial malleolus and stimulator 14 cm proximal to it. In proximal technique stimulation performed on the medial aspect of the knee and response recorded from the leg, 14 cm distal to the cathode. In 204 studied nerves, response obtained in 145 nerves (71%) by distal technique, in 125 nerves (61%) by proximal technique and in 94 nerves (46%) by both techniques. In 176 nerves (86%) response obtained at least by one of two techniques. In men, response obtaining rate by proximal technique (90.5%) was higher than distal one (57%) (P < 0.0001) but in women this rate was 81% by distal technique and 41% by proximal technique (P < 0.0001). Distal technique was more successful than proximal in subjects with higher age (P < 0.05) and higher BMI (P < 0.001). In conclusion, for saphenous nerve conduction study in men, it is better to perform proximal technique primarily but in women distal technique is preferred. Performing the second technique when the first one is failed is suggested.