She comes of a pronounced neuropathic stock. One of her two sisters is nervous and impressionable, and probably a neurasthenic, while the other is subject to hysterical attacks. She herself is of a profoundly nervous temperament; she cannot go to bed without assuring herself several times that no one is concealed beneath it; she suffers from fears and dreads and obsessions of all sorts; she is, in fact, an "unstable," a degenerate.
In one of our patients the symptoms were unilateral, constituting a variable hemichorea.
It is a matter of some difficulty to furnish an adequate description of the movements of the right arm. We note, first of all, that their activity depends on whether the arm is free or held in a fixed position. Voluntary movements are carried out stiffly, but are interrupted by sudden deviations, sometimes of rather a wide range, and highly irregular in distribution. Notwithstanding these breaks, the end to which the movement is directed is always attained with precision.
While L. was an apprentice dressmaker, she occasionally used to make various contortions with her arm, though if her attention was diverted they did not occur, and as a matter of fact she did her work well enough. Once she became familiar with the mechanical act of sewing, the involuntary performances ceased. Before her disease asserted itself, she had commenced to learn the piano, and she continued to make unimpeded progress, as her teacher discovered a method of holding her elbow which checked all convulsive twitches.
The involuntary movements of the right leg were so insignificant as to be almost negligible; they united to produce a sort of irregular tremor which became appreciable only when the patient was very tired or very annoyed. Sometimes a long walk was followed by a certain hesitation in putting the right foot to the ground, and by defective inhibition of the antagonists of the desired movement. Sometimes one foot was knocked against the other, and sometimes the right appeared to assume an equinovarus position. On the other hand, we have seen L. walking in the street with her father, when no anomaly could be detected in her gait. The distraction of any occupation such as dancing or playing a game has the effect, for the time being, of banishing the greater part, if not all, of the spasmodic phenomena.
This is undoubtedly a case of Brissaud's variable chorea of a unilateral type, and a consideration of the symptoms confirms the intimate relationship between it and tic.
Various intermediate forms have been noted. In one of Brissaud's cases, variable chorea and multiple tics co-existed. Féré[140] reports a case of variable chorea preceded by tic, and Bernard another in which starting, trembling, facial tic, variable chorea, etc., were associated.
Tics of phonation are often superadded to the gesticulations of variable chorea. Brissaud refers to the case of a girl of sixteen in whom involuntary movements resembling those of this type of chorea were coincident with a sort of hiccough, and a more or less inarticulate cry; at a later stage the movements became very infrequent, the hiccough was more constant, and the cry developed into a coprolalic ejaculation.
Variable chorea and variable tic are obviously very closely allied. The movements of the latter, however, are distinguished by their greater abruptness and smaller variety. They are tics by reason of their systematisation and co-ordination; they are variable because they pass from one region of the body to another. There is no necessary relation between them; each has an individuality of its own and is independent of the rest. In variable chorea, on the other hand, one movement passes insensibly into another, and the variants of any particular one are legion.
However easy it is, then, to separate the two clinically, it is none the less true that they spring from the same soil of mental defect. Variable chorea differs in nature from other choreas, though its form is the same; it may be distinguished from tic by the type of movement, but in essence it is identical.