Neuralgia and the diseases that resemble it

by Francis Edmund Anstie

PART II.

DISEASES THAT RESEMBLE NEURALGIA.

CHAPTER I.

MYALGIA.

Of all the diseases which superficially resemble neuralgia, none are so likely to be confounded with it, on a cursory glance, as myalgia. More careful inquiry, however, furnishes, in nearly all cases, ample means for distinguishing between the two affections.

Myalgia is an exceedingly painful affection, and it is also much more common than was formerly supposed. It is to Dr. Inman that we undoubtedly owe the demonstration of the frequent occurrence of this malady, and the facility with which it may be mistaken for other, and sometimes much more serious, diseases, with very disastrous results. At the same time, I must express the opinion that this ingenious author has decidedly exaggerated the importance of this local disease at the expense of an unjust depreciation of the frequency and significance of other painful disorders which have their origin within the nervous system.

Myalgia proper includes all those affections which are severally known as "muscular rheumatism" (for the muscles generally), and "lumbago," "pleurodynia," etc. (according to locality). It is essentially pain produced in a muscle obliged to work when its structure is imperfectly nourished or impaired by disease.

The clinical history of the different varieties of myalgia absolutely requires this key for its interpretation; otherwise, the appearance of the sufferers from different kinds of myalgia is so widely dissimilar that we should be exceedingly likely to miss the important features of treatment, which must be applied to them all in common. Nothing, for instance, can be more strikingly unlike than the appearance of the pallid, stunted, under-nourishment cobbler who complains of epigastric myalgia, and that of the ruddy and muscular navvy who suffers from acute lumbago, or the similarly plethoric-looking country commercial traveller, who has been driving in his gig against wind and rain, and complains of violent aching pains in one or both shoulders; yet one and all of these individuals are suffering from precisely the same cause of pain, viz., a temporarily crippled muscle or set of muscles which has been compelled to work against the grain. Why this state of things should invariably be interpreted as sensation in the form of acute pain never absent, but severely aggravated by every movement of the affected part, is a matter beyond our powers of explanation, we must accept it as an ultimate fact for the present.

There is scarcely any need to describe the pain of myalgia, since almost every one has suffered either from lumbago, or from a stiff neck produced by cold. The pain is essentially the same in all cases; it is an aching actually felt either in or toward the tendinous insertions of the affected muscles, and sharply renewed by every attempted contraction of those muscles. The variations in the character and severity of the pains are really entirely due to the greater or the less opportunity for physiological rest which the muscle can obtain. Thus the most obstinate and the most severe, kind of myalgic pain is undoubtedly that of pleurodynia—pain in the intercostal muscles and their fibrous aponeuroses—a fact which depends on the incessant movements which these muscles are compelled to perform in the act of respiration. And next to this in severity and obstinacy are myalgias of the great muscles which are incessantly engaged in maintaining, by their accurately opposed contraction, the erect position of the spinal column and of the head. This rate of proportional frequency and severity, however, must be taken as strictly relative; i. e., it is correct upon the supposition that the different sets of muscles were equally worked and that the state of nutrition was equal in the different parents. It is otherwise when the conditions are reversed. Thus, the unfortunate cobbler or tailor, who sits for long hours in one cramped and bent posture, is continuously exerting his recti abdominales (probably suffering from an under-nutrition common to all his tissues) to a degree perfectly abnormal, and out of all proportion to the functional work he is getting out of any other part of his muscular system. The consequence is, that he comes to us complaining of acute epigastric, and sometimes pubic, pain, rising to agony when he assumes his ordinary sitting posture, and only reduced to any thing moderate by the most complete extension of the whole trunk in the supine posture.