Nervous diseases : their description and treatment / by Allan McLane Hamilton.

  • Hamilton, Allan McLane, 1848-1919.
Date:
1878
Catalogue details

Licence: Public Domain Mark

Credit: Nervous diseases : their description and treatment / by Allan McLane Hamilton. Source: Wellcome Collection.

    24/540 (page 24)
    Dr. E. C. Sep;iiin lias mado a very decided iini)rovement upon tlie oriprinal instrument of Sievekiug. He lias had it constructed of aluminum, and of a smaller size, so that it is light, and may be easily carried in the pocket- case. The principle upon which the assthesiometer is constructed is the fol- lowing: The normal receptivity of tactile impressions enables the subject to distinguish two points which are brought simultaneously in contact with the skin. This susceptibility varies greatly in different regions in proportion to the delicacy of tactile sensation located tlierein. If there be loss of sensation as an accompaniment or result of nervous disease, of course the distance between them will have to be increased before the points will be felt as two. In hyperassthesia they may be much more nearly approximated and distinguished as two than in the aniesthetic state. The average distance at which the two points of the instrument can be felt in the normal state are as follows:— Point of tongue .... Red surface of Hps .... Palmar surface of tliird finger Tip of nose ..... Metacarpal bone of thumb Skin of cheek ..... Mucous membrane of hard palate Dorsal surface of first finger Dorsum of hand over heads of metacarpal bones Mucous membrane of gums Lower part of forehead Lower part of occiput Back of hand ..... Neck unTlcr lower jaw Vertex ...... Skin over the patella Skin over the sacrum Skin over the sternum Skin over cervical vertebraj Skin over middle of back Skin over middle of the arm Skin over middle of the leg 1 line. 2 lines. 1 line. 3 lines. 4 5 6 7 8 9 10 12 14 15 15 16 18 20 24 ,S0 30 30 n Certain precautions must be taken when using the jesthesiometer, or else our examination will be unsatisfactory in the extreme ; we must not depend in all cases upon the patient's statement, but exercise tact in getting from him satisfactory answers, and not guesses. There seems to be in some individuals a discouraging stupidity which prompts them, in answer to the question, How many points do you feel? to oftentimes reply Three, when they know that the instrument has but two points. It is of the greatest importance that the patient's eyes should be covered, or that he should close them, as he will unconsciously look at the instrument durnig its application. It is also of moment that the points should be lairly and