On the seat of headache in the sympathetic nerve, and on some of the rules of treatment, drawn from its connexion with chronic ill health / by William Seller.

Date:
1848
Catalogue details

Licence: Public Domain Mark

Credit: On the seat of headache in the sympathetic nerve, and on some of the rules of treatment, drawn from its connexion with chronic ill health / by William Seller. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    ^ To go back to the first—the case of headache which most dis- tinctly suggests the reference of the sensation to the cranial nerves, is the pain over the left brow in derangement of digestion. This pain is instanced by Todd^ as a well-marked example of reflected sensation, the primary impression being conveyed to the nervous centre through the par vagum, and thence reflected to the extre- mities of the frontal branches of the fifth pair. In this explanation it does not appear why the highest branches, namely, the frontal branches of the ophthalmic portion, should be the channel of the reflected sensation, rather than the branches of the second portion and the sentient branches of the third portion, the points at which these originate being obviously nearer the part of the nervous centre disturbed by the impression conveyed from the stomach through the par vagum. Nor does it appear that there is any greater direct evidence in favour of this explanation which makes the case an anomaly, or at least exceptional, than for the supposi- tion of the pain being really in the anterior part of the left hemi- sphere, consequent on irritation of the gastric filaments of the left vagus nerve, which keeps it within the general law. It is impos- sible to deny, on just grounds, that phenomena entitled to be teimed refiected sensations do occur; but it is an error to regard these as the result of a law extensively applicable to the acts of the animal economy. They seem to arise under the unusual stimulation of sentient nerves, and differ widely in character from reflected motions. Without the constant operation of the great law on which reflected motions are dependent, the animal machine would quickly come to a stand. On the contrary, the phenomena falling under reflected or radiated sensations, are, as it were, erroneous acts of the system, comparatively rare, incidental, forming no part of the ordinary operations in its economy, the result almost uniformly of morbid causes. The conditions on which the unequivocal examples of re- flected sensations arise, are obviously the intenseness of the impres- sion made on the extremities of the nerve first affected, and the proximity in the nervous centre of the origin of the nervous fila- ments, through which the reflected sensation is conceived to be con- veyed. But these conditions are not obviously present when irri- tation of the stomach is supposed to be transferred through the par vagum to the first portion of the fifth pair of nerves, and stUl less when irritation of the bowels, liver, or uterus is represented as ex- citing headache on the like principle. If there be affection of the encephalon at the origin of the fifth pair of nerves, then there may be pain of the scalp, independently of any radiation of sensation, or in accordance with the general law. The second view need not detain us. It must be regarded merely as a last resort, in case the two other views should be dis- 1 Todd and Bowman, Physiology, Tart Tliird, p. 116.