Decreased pain threshold and tolerance in patients with chronic tension headache

Nociceptive processing was studied in 40 patients with chronic tension-type headache and in 40 healthy controls. We found that pericranial tenderness recorded by manual palpation was considerably higher in patients than in controls (p < or = 0.0002). Pressure pain detection and tolerance thresholds recorded in the finger, by means of a pressure algometer, were significantly lower in patients than in controls (p < or = 0.0009), and a non-significant similar trend was observed in the temple (p < or = 0.12). Detection and tolerance thresholds were decreased to a similar degree in patients compared with controls, and pain thresholds recorded in the finger and in the temple were highly correlated (r = 0.84, p < 0.0001). The electrical pain threshold at the labial commissure, by means of an electrical stimulator, was significantly decreased in patients compared with controls (p = 0.03). All of the examined pain thresholds were significantly correlated to the pericranial tenderness recorded by palpation (r = -0.35 to -0.53, p < or = 0.03). We conclude that the present finding of a general hypersensitivity to pain stimuli in chronic tension-type headache indicates that central factors play an important role in the pathogenesis of this disorder.