246 Williafu Christopher Krauss 



Toxic Atrophies. Agents which have been instrumental 

 ill setting up a neuritic process and a consequent wasting of 

 the muscles are— alcohol, lead, arsenic, mercury and bisul- 

 phide of carbon. The atrophy is generally limited to the ex- 

 tensor muscles, as seen in alcoholic paralysis, lead palsy, 

 arsenical pseudo-tabes, and on eliminating the poison from the 

 system, the atrophy sometimes disappears. 



After Infective Processes. Following upon an acute attack 

 of diphtheria, variola, typhoid, typhus, cerebro-spinal menin- 

 gitis, etc., atrophic changes may take place in some of the 

 muscles of the body. The lesion is generally neuritic, the 

 atrophy either the simple or hyaline degenerative, the latter 

 especially in typhoid, variola and cerebro-spinal meningitis. 

 In typhoid fever, typical hyaline degeneration of the rectus 

 abdominis and adductors of the thigh may frequently be met 

 with. 



Arthritic Atrophies. Following injury to joints, atrophy 

 of the muscles moving that joint, but more especially the ex- 

 tensors, is often observed. If the hip joint is the seat of in- 

 jury, there is atrophy of the glutei ; if the knee, the rectus 

 femoris ; if the ankle, the gastrocnemius and soleus. The 

 wasting is quite often pronounced and persistent, with little, 

 if any change in the electrical irritability, and increased tendon 

 reflexes. The seat of the lesion is purely hypothetical. Vul- 

 pian, Charcot and others believe that the articular centripetal 

 nerves convey the irritation to the gray matter and particularly 

 to the motor cells of the ventral cornua, thence to the mus- 

 cles of the joint through the efferent nerves. 



The diagnosis of these neuritic atrophies is not difficult in- 

 asmuch as they are always accompanied by pain over the 

 course of the nerves, trophic and vasomotor disturbances. The 

 wasting is local, limited, generally of a severe type with 

 marked electrical reactions, and, being dependent upon a 

 neuritic process, generally subsides upon cessation of the in- 

 flammation. 



Of late there seems to be a disposition to classify another 

 form of muscular atrophy under this head, namely, the pero- 

 neal type, commonly called the Charcot-Tooth type. Erb and 



