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

In his brief report on the structure of the gray matter of the central nervous system (1873), in which he described the "black reaction", Golgi noted the ramifications of the axon. This discovery prompted the French histologist Louis Antoine Ranvier, one of the first to try the black reaction outside Italy, to propose an ingenious theory of referred pain in his Traité technique d'histologie. Ranvier suggested that the nerve fibers originating from the irritated area and those coming from the region to which the sensation is referred converge on the same axon and thus the same cell body, causing the spatial dislocation of sensation. This theory of referred pain is a powerful example of the extraordinary clinical-physiological impact of the first of Golgi's neurocytological discoveries.

[Illustrations of visceral referred pain. "Head-less" Head's zones]. / Illustrationen zum übertragenen Schmerz. Wie viel von Head steckt in den Head-Zonen?

Reviewing anatomical, physiological and neurological standard literature for illustrations of referred visceral pain only one type of illustration can frequently be found, which is referred to as Treves and Keith. In fact, the original illustration as a model for most current pictures stems from the German edition of Sir Frederick Treves' famous book "Surgical Applied Anatomy" from 1914, which was reillustrated for didactical reasons for the German readership. While neither Treves and Keith nor the German illustrator Otto Kleinschmidt ever published any work on referred pain this illustration must have been adapted or copied from older sources by the illustrator. Therefore the comprehensive systematic original works before 1914 were reviewed, namely those of Sir Henry Head and Sir James Mackenzie. Due to the name of the phenomenon in the German literature of Head's zones, the illustrations were expected to be based mainly on Head's work. However, a comparison of all available illustrations led to the conclusion that Kleinschmidt chiefly used information from Mackenzie as a model for his illustration. Due to the inexact reproduction of Mackenzie's work by the illustrator some important features were lost that had been reported by the original authors. These include the phenomenon of Head's maximum points, which nowadays has fallen into oblivion.Therefore current charts, based on the illustration by Kleinschmidt from 1914, lack experimental evidence and appear to be a simplification of the observational results of both Head's and Mackenzie's original systematic works.

Sources and patterns of pain in lumbar disc disease: revisiting Francis Murphey's theory.

OBJECT: Francis Murphey's theory was analyzed to determine whether or not his opinion is evidence-based medicine and whether or not it can be applied clinically. METHODS: The English literature was reviewed using Medline in reference to Dr. Murphey's theory of discogenic chronic LBP, which was first postulated in 1967. Deductive and inductive logic was utilized for the evaluation of his theory. We reviewed and analyzed his unprecedented study of the annulus fibrosus (AF) and posterior longitudinal ligament (PLL) under local anesthesia that was presented to the Congress of Neurological Surgeons in 1967 and 1972. RESULTS: He reported that: "It is found that the posterior longitudinal ligament and the remaining annulus fibrosus over the herniated discs are also exquisitely tender; even the slightest pressure on them produces pain." We noticed that in Dr. Murphey's presentation, he did not disclose any hard data, yet he concluded: "when an incomplete tear in the annulus occurs and if the tear is in the midline posterior, a fragment of nucleus will protrude in this tear, stretching the annulus and posterior longitudinal ligament, causing midline back pain. If the tear in the annulus is lateral, the pain is over the sacroiliac joint in the buttock and hip, and 20% of the patients in the lower abdomen, groin or testicle on that side." CONCLUSIONS: Because of a flaw in his understanding, in our opinion the unproven mechanical theory of discogenic LBP is weak inductive logic and does not justify discography and intra-discal procedures.