We will now discuss very briefly the muscular atrophies con secutive to diseases of the nervous system, but will not enter into any details of symptomatology or pathological anatomy, as that would lead us into a description of all the nervous diseases in which any affection of the muscles occurs. For this the reader must be referred to the later volumes of this series, in which these diseases will be treated of at length. We must content our selves here with a simple enumeration of the various maladies of the nervous system in the course of which muscular atrophies are observed.
In the first rank of these affections come the diseases of the spinal cord. Atrophy of the muscular tissue is not rare in locomotor ataxia ; it belongs as a rule to an advanced period of the disease, and not infrequently leads to a characteristic deformity of the foot known as tabetic club-foot. In the upper extremities we find atrophies of the Aran-Duchenne type, that is, symmetrical atrophies beginning in the abductor brevis of the thumb and advancing to the hands and upper extremities. In Friedreich's disease there is sometimes atro phy affecting certain muscles of the trunk or limbs.
But the type of muscular atrophy produced by medullary lesions is certainly that represented by the disease known since the descrip tion of Aran and Duchenne as progressive muscular atrophy. As we have just seen, this affection always begins in the hands and invades successively and symmetrically the segments of the upper extremity, passing thence to the muscles of the trunk. We have seen in the section on primary trophic disturbances of the muscles that Du cheune at first confounded this my elopathic atrophy with another form not accompanied by appreciable nervous lesions which we have called progressive myopathic atrophy. It is in progressive muscular atrophy that one observes the characteristic deformities of the hand called variously claw-hand, monkey-hand, main en griffe, main de squelette.
The other diseases of the spinal cord, scleroses and inflammations, are frequently accompanied by muscular atrophies.
There are certain forms of muscular atrophy consecutive to dis eases of the brain. It is not uncommon, indeed, to observe atrophy of the paralyzed and contractured muscles after hemorrhage or soft ening of the brain. Descending scleroses affecting directly the mus cles may follow these lesions.
Finally we have the entire category of peripheral neuriticles which may induce a diminution of volume of the affected muscles. The type of these forms of peripheral neuritis is alcoholic neuritis. I have referred to this in speaking of muscular atrophies of toxic origin.
After this general sketch of the etiology of secondary trophic affections of the muscles, we may represent the subject graphically in the following table : Treatmeni. —There are two points to be considered in the thera peutic management of the case when the presence of these muscular troubles has been determined. In the first place we must address our efforts to the relief of the primary causal affection, and secondly endeavor to bring about an improvement in the muscular condition. We must therefore determine the cause of the trouble, and if possible remove it. For example, when the muscular affection is consecutive to a lesion of the brain or cord we may suspect the presence of syphi lis, and may administer, occasionally with profit, large doses of iodide of potassium to which may be added some mercurial preparation. For the relief of the atrophy we must have recourse to massage and electricity under its different forms. It is well to say that the results of this treatment will often be far from brilliant, especially when the troubles are consecutive to lesions of the nervous system.
We have now concluded the study of diseases of the muscles. I have been very cursory in the discussion of the secondary trophic disturbances, the consideration of which belongs to another part of medical pathology. Nevertheless I should have preferred to develop at somewhat greater length this as well as some other divisions of my subject, but it has for various reasons been impossible to carry out my desire.