PALSY OF THE SERRATUS MUSCLE. 



371 



on account of the development of a palsy of the right serratus muscle. 

 Some time afterward, palsy of the left serratus also began to appear. 



SYMPTOMS AND COURSE. Palsy of the serratus muscle is easy of 

 recognition, as the absence of its function and the undue action of its 

 antagonistic muscles occasion characteristic deformities and disorders 

 of motion. The function of the serratus is to press the scapula against 

 the thoracic wall, and to draw its lower angle downward and outward. 

 The serratus is especially required in the act of elevating the arms 

 above a horizontal line, as it then draws the lower angle of the scapula 

 outward, and turns the glenoid cavity of the joint upward. It is by 

 this act alone, and not by the contraction of the deltoid, that we are 

 enabled to lift the arm above the shoulder. When the serratus is 

 paralyzed, the inner border of the scapula, and particularly its lower 

 angle, instead of lying against the chest, stands up like a wing, draw- 

 ing up a three-cornered fold of skin before it, and admitting of our 

 reaching deeply into the subscapular fossa. At the same time, the 

 lower edge of the scapula stands up too high, and too far inward. 

 The antagonistic muscles, the trapezius and the levator scapulae, have 

 drawn the superior angle upward, and the weight of the arm and the 

 pectoralis minor have depressed the external angle, and thrown it for- 

 ward. The patient is unable to lift his arm above a horizontal line, 

 and is thus rendered extremely awkward. Any one, who has often 

 watched a patient with this affection put on or take off his coat or 

 shirt, will be able to make a diagnosis in the next case he meets with, 

 from these acts alone. If we press the inferior angle of the scapula 

 against the chest, and, at the same time, push it in, the patient is once 

 more enabled to lift his arm above his shoulder without difficulty. 

 Palsy of the serratus is an obstinate complaint. In none of the cases 

 which I have seen was a complete cure effected. In many in- 

 stances, however, the patients so far improved as to be able to do 

 easy work. 



TREATMENT. The most commendable remedy, in recent palsy of 

 the serratus, is local blood-letting and derivation to the skin, applied 

 over the point where the long thoracic nerve passes through the sca- 

 lenus medius. In chronic cases, according to our present experience, 

 faradization does not promise much benefit. On the other hand, the 

 constant current is strongly to be recommended. Unfortunately, how- 

 ever, hitherto I have had but one opportunity of applying it. The 

 cures obtained by means of the constant current, in cases of peripheraJ 

 facial patay, which I consider to be quite analogous with palsy of the 

 serratus, urgentlv demand the treatment of the latter by galvanism. 



