Sensitivity, low-frequency filter, high-frequency filter, sweep speed, duration of pulse, rate of pulse, and the machine used were not specified.

This study was performed in the supine position.

Following the orthodromic method [1], the median sensory nerve conduction studies were performed with comparison of the palmar cutaneous branch (PCB) and digit I nerves (Fig. 1). Recording electrodes (1 cm) mounted on a plastic bipolar bar, with an interelectrode distance of 3 cm, were placed longitudinally at identical distances (10 cm) over the median nerve at the wrist and at the distal forearm, with the orientation of the two recording electrodes along the line of the nerve. For the digit I sensory response (R1), recording electrodes were placed 10 cm at the wrist (proximally to the distal wrist crease). For the PCB response (R2), recording electrodes were placed 10 cm on the distal forearm. For both sensory recordings, the active electrode (A) was placed proximal to the distal crease at the wrist, and the reference (R) was placed proximally. Ground (G) electrode was placed on the palm of the hand. Digit I (R1) and PCB (R2) sensory recordings were made separately.

The sensory nerve conduction studies were done orthodromically. The finger to wrist sensory nerve conduction (S1) study was done with stimulation by ring electrodes at the digit I with the cathode electrode (−) around the base and the anode electrode (+) 2–3 cm distally around the distal interphalangeal joint of the same digit. The thenar eminence to the distal forearm sensory nerve conduction (S2) study was done with stimulation by disk electrodes placed on the thenar eminence with the active cathode (−) proximal to the wrist crease and the anode electrode (+) placed distally. Stimulation parameters were not specified in the article.

Peak latency (ms) was measured from the onset of the stimulus to the peak of the negative deflection of the evoked sensory nerve action potential (SNAP). Amplitudes were not considered for analysis. The distance between the stimulating and recording electrodes was fixed (10 cm) for both S1–R1 and S2–R2 conduction studies. Latency was converted in the sensory nerve conduction velocity (SNCV) by dividing the latency into the distance. Skin and room temperature were not given. Normal values (Table 1) were obtained in 40 healthy subjects (age range 22–60 years, mean age 38.6 years); pathological data (Table 2) were recorded in 50 patients (16 men and 34 women, age range 25–64 years; mean age 42.3 years) with clinically suspected carpal tunnel syndrome (CTS).