1 - Pain

Introduction . . . . . . . . . . . . . . . . . . . . . . . 6 Possible mechanisms . . . . . . . . . . . . . . . . . . 6 Clinical consequences . . . . . . . . . . . . . . . . . . 7 Rules of referred pain . . . . . . . . . . . . . . . . . . 7 Dermatomes . . . . . . . . . . . . . . . . . . . . . . . 9 Discrepancies between dermatomes and myotomes . . . . . . . . . . . . . . . . . . . . . . . 14 Referred pain in visceral diseases. . . . . . . . . . . 15 Referred pain is felt deeply and distally in the dermatome. . . . . . . . . . . . . . . . . . . . . . . 15 Segmentally referred pain does not cross the midline . . . . . . . . . . . . . . . . . . . . . . . 16 Dura mater an ‘exception’ to segmental reference . . . . . . . . . . . . . . . . . . . . . . . . 16 Referred tenderness . . . . . . . . . . . . . . . . . . 16 Factors determining reference of pain . . . . . . . . 18