Radial sensory conduction in the hand.

Radial sensory conduction has traditionally been performed by stimulating the nerve at the wrist, recording from the thumb or the base of the first web space. This paper describes a technique for measuring conduction in the more distal branches on the dorsum of the hand. Comparison is made with dorsal ulnar sensory conduction, and the area supplied by each nerve on the dorsum of the hand is investigated. Radial conduction was found obtainable to the area between the second and third metacarpals (MCPs) in all patients with a velocity of 56.8 +/- 4.2 m/sec. Conduction to the space between the third and fourth MCPs could be obtained in only 65% of the hands with a mean velocity of 58.9 +/- 4.5 m/sec. Dorsal ulnar sensory conduction to the same area was 59 +/- 4.2 m/sec and was present in 73% of the hands. Forty percent of patients have both radial and ulnar innervation to the area between the third and fourth MCPs on at least one side, while 33% have both radial and ulnar innervation to this area bilaterally.