C2 and C3 pain dermatomes in man.

This report defines the C2 and C3 pain dermatomes by the distribution of: the hypalgesia clearing after surgical root decompression; the dysaesthesias produced by electrical root stimulation; and the hypalgesia produced by anaesthetic root block. The C2 pain dermatome, so defined, consists of an occipital parietal area 6-8 cm wide, ascending paramedially from the subocciput to the vertex. The C3 pain dermatome is a craniofacial area including the scalp around the ear, the pinna, the lateral cheek over the angle of the jaw, the submental region and the lateral and anterior aspects of the upper neck. These C2 and C3 pain dermatomes do not overlap and are smaller than the C2 and C3 tactile dermatomes described in the literature.