90 PHYSIOLOGY CHAP. 



Neuropathology presents many such cases. Anaesthesias ut' 

 hysterical origin, those of traumatic neurosis, and those observed 

 in syringomyelia are comparatively common. These patients 

 sometimes retain the power of carrying out all movements with 

 the affected limbs in a normal or almost normal manner, so long 

 as their eyes are open. But when the eyes are shut they lose 

 consciousness of the movements they are making, and are unable 

 to describe the position actively or passively taken up by the 

 anaesthetic limb. These cases are difficult to interpret. It may 

 be thought that the anaesthesia is confined to the cutaneous nerves. 

 and that this, on Schiff's theory, involves loss of muscular con- 

 sciousness (Magnin, Oley, and others). But more probably the 

 defect depends on abolition or suspension of both cutaneous and 

 muscular sensibility (Beaunis and others). 



This is apparent from a case described by Striimpell (1902) of 

 total paralysis of every kind of sensation in the forearm and right 

 hand, with complete preservation of motility, in a patient who 

 received a knife-wound in the cervical spine which probably cut 

 through the grey matter of the dorsal horn and the lateral portion 

 of the right dorsal column. The injury was followed by a com- 

 plicated illness with widespread symptoms; but when the wound 

 healed after about nine months, all the symptoms were confined 

 to the right upper limit. With closed eyes the patient was unable 

 to say whether the lingers of his hand were flexed or open, or to 

 maintain it in any posture in which he was placed with his eyes 

 open (Figs. 36 and 37). . Under the control of vision he was able 

 to exert a strong pressure with his hand and to place the fingers 

 in any position; with shut eyes he was incapable of carrying out 

 any definite, complicated movement with that hand, or of extend- 

 ing or flexing it at command. 



This is a clear demonstration that the abolition of superficial 

 and deep sensibility in the hand and forearm renders the patient 

 incapable, without the use of his eyes, of accurate sensation either 

 of the position or of the active and passive movements of the 

 hand or fingers. 



From our standpoint cases of well-authenticated dissociation 

 of superficial and deep sensibility are more interesting. Clinical 

 cases have been well described, in which the sensibility of the 

 deep tissues was wholly or partly retained, while cutaneous sensi- 

 bility was entirely abolished. In a hysteric described by Duchenne 

 (Boulogne) there was total insensibility of the left upper limb 

 (analgesia, anaesthesia, insensibility of muscles to electrical and 

 mechanical stimuli), although the patient, even with closed eyes, 

 was aware of the active and passive movements of the limb, could 

 estimate the weight of objects placed in the hand, and did not let 

 them drop, proving, according to Duchenue, that the sensibility 

 of the articular tissues persisted. 



