On the Segmental Distribution of Sensory Disorders

Visceral organ cross-sensitization — An integrated perspective

“…However, it was not until the late 19 th century that potential mechanisms underlying this well known symptom - referred pain - were advanced as reflecting a “commotion” or “irritable focus” in spinal segments receiving input from an organ (Ross, 1888; Sturge WA., 1888). These concepts were later expanded and formulated as the “convergence-projection” theory of referred visceral sensation (Ruch, 1965), convergence denoting input from both somatic and visceral structures onto the same second order spinal neuron (see Ness and Gebhart, 1990, and Gebhart and Ness, 1991 for more extensive discussion).…”

Experimental Evidence on the Nature of Cutaneous Hyperalgesia

“…It was found that the thermal pain threshold was not lowered, but that, as in secondary hyperalgesias induced by other means and described above, the sensation of pain at threshold was more intense and longer lasting. Moreover, a stimulus producing a pain of 4 dol intensity in control areas, produced pain of 6 dol intensity in the hyperalgesic area (see Figure 15). Moreover, when the hyperalgesic area was mechanically stimulated by tapping with the finger or by gentle pressure, not only was local tenderness evoked, but the pain from the inflammation in the ear was markedly increased from an intensity of 1 dol to 4 dols.…”

“…Observation 4 Increased "sensibility" of pain in deep structures associated with skin injury It was noted while the second and third injuries were being produced that not only was a burning sensation in the zone of skin injury experienced but as well a deep ache extending to the elbow and shoulder. The skin pain subsided rapidly after the burns were produced but four minutes later the subjects complained of aching sensations in the wrist, and in the ulnar side of the hand as well as in the shoulder.…”

“…As seen at the bedside there are apparently several varieties of hyperalgesia, and few clinical phenomena are more difficult to understand and to evaluate. The literature on the subject includes work of a distinguished roster of investigators (3)(4)(5)(6)(7)(8). As a result of these studies two classes of hyperalgesia have been loosely formulated, namely, that occurring at the site of injury, and that associated with the injury but occurring in undamaged tissue.…”

Golgi and Ranvier: from the black reaction to a theory of referred pain

“…His theory of referred pain is a very significant example of the clinical-physiological impact of the first of Golgi's neurocytological and neuroanatomical discoveries. After Ranvier, other developments led to the modern concept of referred pain, linked primarily with the names James Ross, William Allen Sturge, Henry Head and James Mackenzie (Breathnach, 1994;Ross, 1887;Sturge, 1888;Head, 1893;Mackenzie, 1893;Rey, 1995), and now interpreted according to the "convergence projection theory" (Ruch, 1949), which postulates the convergence of afferent visceral fibers into the spinal somatic sensory neurons which give origin to the spinothalamic tract.…”