AFFECTIONS OF SENSATION
Generally speaking, objective disturbances of sensibility do not occur, and while subjective changes are more frequent, they may be entirely lacking even in long-standing and aggravated cases. What the patients usually complain of is a more or less persistent, disagreeable, uncomfortable sensation, rarely described as painful, and often compared with a feeling of stiffness or fatigue. Or, again, they may be conscious of a sense of constriction or of dragging in the affected muscles, either at their insertions or in the muscle belly, or sometimes in the joints concerned. These subjective sensations are characterised by extreme variability in time and in degree. Moreover, the accounts given by patients of their own sufferings ought to be accepted with reserve. Not merely are they ready to exaggerate and incapable of accurately depicting and localising their sensations, but they also exhibit a curious tendency to false interpretation: they attribute an erroneous pathological significance to their feelings, and proceed to elaborate a thousand ridiculous variations, thereby inviting in a sense the eruption of fresh tics. In all this behaviour their mental imperfections are abundantly manifest.
We may remind ourselves in this connection how O.'s various inventions had no other effect than that of provoking new tics, and another illustration is to hand in the case of S., an account of whose mental torticollis will be found in a previous chapter.
Any trifling item of passing interest used to make S. forget altogether the more or less acute pain he experienced in his neck and shoulders, and reacted no less successfully on his torticollis. When systematic and methodical exercise of the muscles was ordered, nothing was more natural than that their long period of inactivity should have the result of causing a vague feeling of stiffness in them with the unwonted action. Yet S. never dreamed of such an ordinary explanation, but pessimistically exaggerated the sensation, and deemed it an infallible sign of the spread of the disease. It proved to be a simple enough matter, however, to convince him of its harmlessness, for it was sufficient to remind him of the corresponding stiffness he had felt after his first attempts at riding and fencing, and from that moment he ceased to pay any attention to it and therefore to complain.
With spasm, on the other hand, pain is more frequently, though not always, associated. It may be said, of course, that since a tic may be evolved from a spasm, the pain of the latter is really the exciting cause of the former, but in the tic as it is constituted all these initial disturbances have disappeared, and what the patient does feel is the consequence of excess of muscular action or of articular displacement. His dolorous sensations form the sequel, not the prelude; they are not symptoms, but, so to speak, complications.
CHAPTER IX
THE DIFFERENT TICS
THIS chapter we shall devote to a review, necessarily incomplete, of the principal sites in which tics are to be met with. We do not pretend to have collated every known case observed up to the present, and we foresee the likelihood, moreover, of new tics coming into being. Their numbers are as unlimited as is the diversity of functional acts of which they form the pathological expression. We must content ourselves, then, with the consideration of the most familiar and most recent examples.
A rational classification would entail discussion of the various modes of derangement to which functional acts are liable, and this would demand in its turn a preliminary tabulation of function. How onerous such a task is, is patent from the uniform imperfection of the attempts already made, and the equivocal nature of their conclusions.
We have studiously avoided the designation of a tic by the muscle or muscles that determine it. To specify the precise muscle involved is sometimes attended with no little difficulty, while if several, as is customary, are concerned, their association is rarely anatomical; indeed, this is one of the chief aids to diagnosis between tics and spasms. Should the convulsion chance to follow an anatomical distribution, neighbouring muscles are apt to participate as well. Hence it is advisable to name a tic after its morphological situation, or, better still, from the functional act of which it is, in Charcot's phrase, the caricature.
This is the plan we shall pursue in our successive examination of the different parts of the body disposed to be the seat of tics.