The most elementary of these, and at the same time the most common (says Guinon), is the involuntary exclamation. In the midst of his tics and grimaces, a cry—ah!—escapes the patient's lips at intervals, a shrill, sudden, and momentary cry which interrupts his talk, or breaks in on a period of silence, and which he repeats only once or perhaps several times in succession. The thread of his conversation, nevertheless, is seldom if ever discontinuous, and his audience is witness of its rationality and accuracy of expression. Rather more complicated is the ejaculation "ouah!" Sometimes one meets with noises that are faithful reproductions of the sounds emitted by various animals.
Guinon is disposed to exclude such simple involuntary explosions as "ahem! ahem!" from the tics, though he admits the analogy to them. He says the sound exactly resembles the trifling little clearance of the throat which is repeated a thousand times a day by people suffering from chronic angina. We, however, are inclined to look upon it as an ordinary spasmodic reaction evoked by some laryngeal or pharyngeal irritation, which in spite of the removal of the latter continues to take place, and because of its meaningless repetition is fairly to be classed as a tic. All that we have said of blinking, for instance, is applicable in this connection.
Of course the embellishment of one's discourse with more or less audible expirations is of frequent occurrence: the hesitating eh ... eh ... to which children give vent in the recitation of their lessons is not confined to them alone. It can scarcely be maintained that these laryngeal noises are tics, since their production is coincident with the exercise of the faculty of speech; hence they are not unlike "functional cramps." On the other hand, the unexpected bark or gurgle that breaks the silence is a pure tic of phonation.[117] Those who suffer in this way reveal characteristic stigmata in the immediateness of the compelling idea and the exaggerated nature of the subsequent satisfaction. To unravel the intricacies of the origin of these tics is a matter of considerable difficulty, though probably imitation is not without influence in their genesis. Reference will be made later to a tic of this kind attributed by Charcot to imitation.
Among the insane similar cries are often the outcome of delusions. At the Congress of Limoges a case was reported by Briand of an old man who imagined himself transformed into a clock and swung his arms with pendulum-like regularity, indicating the hours by uttering raucous sounds at the proper intervals. However curious these sounds were, the fact of their being appropriate is decisive against their classification as tics.
Unmistakable tics of speech, however, do occur.
Speech is a complex of different muscular acts, and, being so, is liable to be disarranged in various ways, by defect in respiration, phonation, articulation, even in ideation. Organic affections aside, it is inadmissible to describe as tics each and all of the functional disturbances of speech that are not based on any discoverable material lesion of nerve centres. One must in fact distinguish between troubles of speech confined to occasions when the faculty is in operation and those that consist in not merely useless but inopportune utterance. However arduous it may occasionally be to draw this distinction, however common the occurrence of transitional forms, it has the advantage of limiting the scope of the term "tic of language." To the latter category only can the description be applied.
For this reason we think it preferable to exclude stammering, stuttering, and all defects of phonation or articulation whose existence is revealed only in the act of speaking. At the same time reference must be made to facts linking these functional anomalies to the tics, and to instances of the latter existing with or succeeding the former.
Such is the case with stammering.
According to Letulle,[118] stammering is a tic of speech whose beginning is a functional disturbance of nervous centres, as is that of tics in general. Holding as we do, however, that one of the features of tic is its appearance in season and out of season, we cannot class stammering as a tic, since its exhibition is restricted to the exercise of a certain function, viz. speech. It is therefore comparable to a "professional cramp," and we may briefly note the analogies it offers to the tics.
Stammering,[119] which in more than fifty per cent. of cases is hereditary, and associated with a neuropathic diathesis, usually betrays itself in childhood and becomes aggravated at puberty. The old idea which credited stammerers with exceptional intellectual powers, in whom, however, rapidity of thought surpassed rapidity of action on the part of the muscles of articulation, is exploded, and to-day those thus afflicted are assigned their true place among the volitionally infirm. In a few rare cases stammering has been due to organic disease of the centres for articulate speech, or of bulbo-pontine nuclei; it has been supposed also to result from genuine spasm on a reflex arc, and this is a possible explanation; as a general rule, however, the pathogeny of stammering is identical with that of tic. Its dependence on such affections of nose, larynx, and pharynx as hypertrophic rhinitis and adenoids has been emphasised by Biaggi[120]; and Derevoge,[121] in directing attention to the association of volitional enfeeblement with respiratory troubles, remarks that stammerers sometimes have a phobia for certain words. Many observers have been convinced of the psychical nature of the affection from the fact of its disappearance during singing, as well as from the effect anger, elation, and other stimuli have in momentarily inhibiting it. The same is of course true of the tics.