TICS OF THE TONGUE—LICKING TICS
Tics confined exclusively to the tongue are of rare occurrence. Moreover, they must be strictly differentiated from the tonic or clonic contractions of the tongue muscles met with in hysteria, epilepsy, and Sydenham's chorea, from the varying tremors that accompany organic disease of cerebral or bulbo-pontine origin, as well as from those "glosso-spasms" that may or may not be associated with twitches of the facial musculature.
Functional polymorphism is no less marked in the case of the tongue than in that of the lips; it participates in suction, mastication, deglutition, as well as in respiration, phonation, and articulation, while to "put out the tongue" at any one is equivalent to an expression of contempt. It is, accordingly, no surprise to find the number of tongue tics very considerable. Such, for instance, is the licking tic, where the tongue is constantly being passed over the free border of the lips, moistening them to excess; or the chewing tic, in which its perpetual motion inside the mouth in every direction conveys the impression that the subject is chewing something. Further, its contact with the palate or the upper lip may yield different clucking, whistling, or crowing sounds. Letulle remarks that the trick of producing a little inspiratory whistle by the passage of a column of air through an incompletely closed labial commissure—a common habit among people suffering from dental caries—is not slow in developing into an actual tic.
It has not fallen to our lot to observe the tonic variety of tongue tics, none the less must we believe in the possibility of their occurrence. Convulsive lingual movements, consecutive to disease of mouth or teeth, or to lesions of corresponding nerves, are in all probability spasms properly so called, to which disturbances of sensation and of nutrition are often superadded. The tonic contractions of tongue, lips, and masseters, which have been described in cases of hypochondriasis and puerperal psychosis, are much more nearly allied to the tonic type of tic, if, indeed, they are not to be identified with it. A case has been put on record by Lange of tonic contraction of the tongue during speaking and eating, each time that it touched the dental arches. No doubt the condition was a sort of tonic tic. Sometimes players of wind instruments are afflicted with a "professional cramp" of the tongue, as Strümpell has reported.
Generally speaking, however, it is particularly in tics of language, and in the various kinds of stammering, that the tongue muscles are concerned.