BRIEF, PROLONGED AND REPEATED STIMULI APPLIED TO HYPERALGESIC SKIN AREAS - A PSYCHOPHYSICAL STUDY

In this experimental study brief/prolonged and single/repeated, nocice ptive stimuli (laser, thermode and electrical) were used to investigat e sensory changes in capsaicin-induced primary and secondary hyperalge sia. The pain threshold to prolonged thermode stimulation was reduced in the primary area and remained constant in the secondary area. The p ain thresholds to brief laser and electrical stimuli remained constant in the primary but reduced in the secondary area. The summation pain threshold to repeated (five stimuli delivered at 0.5, 1, 2 and 3 Hz) l aser and electrical stimuli was reduced in the secondary area. The sti mulus response functions to single laser and electrical stimuli were i ncreased in the secondary area.