Previous to its introduction as a technical term, the word tique, ticq, tic, was in current use in France, and applied in the first place to animals. In 1655 Jean Jourdin described the tique of horses. In eighteenth-century literature tic appears in the sense of a "recurring, distasteful act"—as expressed by the Encyclopædia—especially in individuals revealing certain eccentricities of mind or character. This old-time opinion is worth remembering, particularly in view of latter-day theories.

Once adopted by the eighteenth-century physicians, the application of the word was extended in various directions. André (1756) was the first to mention tic douloureux of the face, an affection excluded to-day by common consent from the category of true tics. Simple, painless convulsive tic, spreading from face to arms, and to the body as a whole, was differentiated by Pujol in 1785-7. During the earlier half of the nineteenth century no solid progress was achieved by the work of Graves, François (of Louvain), Romberg, Niemeyer, Valleix, or Axenfeld. It is to the clinical genius of Trousseau that we owe the rediscovery of tic, the careful observation of its objective manifestations, and the recognition of accompanying mental peculiarities.

In spite of the fact that he considered it a sort of incomplete chorea, and classed it[2] nosologically with saltatory and rotatory choreas and with occupation neuroses, Trousseau's original account remains a model of clinical accuracy:

Non-dolorous tic consists of abrupt momentary muscular contractions more or less limited as a general rule, involving preferably the face, but affecting also neck, trunk, and limbs. Their exhibition is a matter of everyday experience. In one case it may be a blinking of the eyelids, a spasmodic twitch of cheek, nose, or lip; in another, it is a toss of the head, a sudden, transient, yet ever-recurring contortion of the neck; in a third, it is a shrug of the shoulder, a convulsive movement of diaphragm or abdominal muscles,—in fine, the term embodies an infinite variety of bizarre actions that defy analysis.

These tics are not infrequently associated with a highly characteristic cry or ejaculation—a sort of laryngeal or diaphragmatic chorea—which may of itself constitute the condition; or there may be a more elaborate symptom in the form of a curious impulse to repeat the same word or the same exclamation. Sometimes the patient is driven to utter aloud what he would fain conceal.

The advantage of this description is its applicability to every type of tic, trifling or serious, local or general, from the simplest ocular tic to the disease of Gilles de la Tourette. Polymorphism is one of the tic's distinguishing features.

Apart from his studies in objective localisation, Trousseau, as we have seen, recognised that the tic subject was mentally abnormal, but the credit of demonstrating the pathogenic significance of the psychical factor is Charcot's. Tic, he declared,[3] was physical only in appearance; under another aspect it was a mental disease, a sort of hereditary aberration.

Advance along the lines thus laid down has been the work more especially of Magnan and his pupils, of Gilles de la Tourette, Letulle, and Guinon. A meritorious contribution to the elucidation of the question is the thesis of Julien Noir, written under the inspiration of Bourneville and published in 1893. The still more recent labours of Brissaud, Pitres, and Grasset in France, and of others elsewhere, have added materially to our knowledge.

Confining ourselves for the present to the discussion of the latest interpretations put on the word tic, we may be allowed the remark that if the influence of Magnan's teaching has been instrumental in making our idea of tic conform more to the results of observation, nevertheless his view is not without its dangers.

In the opinion of Magnan and his pupils, Saury and Legrain[4] in particular, the tics do not form a morbid entity; they are nought else than episodic syndromes of what Morel called "hereditary insanity," that is to say, of what is usually designated nowadays "mental degeneration."