HISTORIQUE

La première description du phénomène de la roue dentée est généralement attribuée à Harold Moyer (1911), mais Camillo Negro a récemment revendiqué Ja priorité. N’ayant pu nous reporter qu’à l’une des deux descriptions, celle de H. Moyer, nous ne sommes pas en mesure de trancher le débat. Nous nous bornerons donc à rapporter le texte de H. Moyer, en le faisant suivre des remarques par lesquelles, dans un article de 1921, C. Negro réclame la priorité. Nous eussions voulu rapporter le texte même auquel se réfère C. Negro (Archives italiennes de biologie (1901), mais nous avons été, à notre regret, dans l’impossibilité de le faire.

Voici présenté, avec la traduction, l’article que H. Moyer faisait paraître dans le New Journal of the American Medical Association (vol. Lvnr, n° 27, 30 décembre 1911, p. 2125).

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A new diagnostic sign in paralysis agitans ff the cogwheel resistance of the extremities

For a number of years I have observed a symptom in paralysis agitans that it is not recorded in the literature. For the want of a better term, I have ventured to call it the « the cogwheel resistance of the extremities ». This is suggested by the use of such terms as « bad pipe » and « waxy flexibility. These terms describe a resistance which is felt where is impassed motility in passive movements of the extremities. The term cogwheel is proposed as in a certain sense descriptive of a jerky or intermittent resistance of the extremities, when the sign is looked for. It is elicited by the examiner grasping the wrist with one hand and steadying the arm with the other, above the elbow. Rapid flexion and extension of the arm is made. Instead of an even movement, without resistance, when there is no involvement of motility, one two or perhaps three slight hindrances to the movement are experienced by the examiner, which communicates to the hand of the examiner a jerky feeling.

This is not sufficient to stop the movement of the extremity, si that it may be seen, but it is readilly appreciated by the hand of the examiner. After the extremity has been passively moved for à short time,