The diagnostics of pain : lectures for medical students and physicians held at the University of Copenhagen in the autumn of 1934 / by Th. B. Wernøe.

  • Wernøe, Th. B. (Thorvald Benedikt), 1884-1936.
Date:
1936
Catalogue details

Licence: In copyright

Credit: The diagnostics of pain : lectures for medical students and physicians held at the University of Copenhagen in the autumn of 1934 / by Th. B. Wernøe. Source: Wellcome Collection.

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    After the skin has slipped back the patient is told to find the tender spot with his finger. Without exception this is always pointed out as corresponding exactly to the place of compression of the bone, not the place of compression of the skin. Hence it appears from these experiments that the bone tissue and the periosteum are more sensitive to pressure with a blunt instrument than the skin, whereas, conversely, the skin is more sensitive to pin-pricks. Perhaps the insensibility of the bone to pin-pricks is con¬ nected with a fact pointed out already by Gowers who in his lectures issued a warning against the use of pointed needles for sensory examinations, because a pointed needle, in places where a sensory reticulum is found, perhaps may enter one of the meshes without touching the sensory nerve elements themselves. A blunter needle has a greater chance of touching these, and so he recommends the use of a common pen, neither excessively pointed nor excessively broad, instead of a pointed needle. Perhaps there is, as far as the periosteum and the bone tissue are concerned, a network of nerves into the meshes of which the point of a needle may slip without producing pain, whereas the blunt instrument acts on a larger surface and hence can only with difficulty avoid touching sensory nerve elements, even though these form a relatively wide-meshed net. In the last instance the sensibility of the tissues is probably dependent on the function of the tissues, since the skin, which serves as a protection against highly varying stimuli of the external kind perhaps for that very reason is sensitive to a series of different stimuli, whereas the deeper-lying tissues are only sensitive to a smaller number of stimuli, and principally those to which the tissue in question is usually exposed owing to its situation and function. The bone tissue, according to its position, structure, and function, will chiefly be exposed to pressure and blows. It is not surprising, therefore, that it is more easily irritated by pressure and blows than by pricks or other external stimuli, which only exceptionally reach the periosteum or the bone.
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