GENERAL SUMMARY. PATHOLOGICAL APPLICATIONS. 383 



the loss of consciousness which accompanies the convulsion.' Many forms 

 of that protean malady, Hysteria, are attended with a similar irritability of 

 the Nervous Centres ; but there is this remarkable difference in the two cases, 

 that the morbid phenomena of Hysteria, whilst they often simulate those 

 of Tetanus, Hydrophobia, Epilepsy, &c., are evidently dependent upon a state 

 of the system of a much less abnormal character, being frequently relieved 

 by very mild remedies, and being often capable of prevention by a strong 

 effort of the will. Dr. Hall has pointed out an important distinction between 

 Epilepsy and Hysteria, which materially influences the proximate danger of 

 the paroxysm of each respectively ; in the former, the larynx is convulsively 

 closed, and partial asphyxia is the necessary result, if the access of air be too 

 long prevented, so that venous congestion ensues, increasing the disorder of 

 the nervous centres even to a fatal degree ; in Hysteria, on the contrary, much 

 as the larynx is affected, it is not usually closed. Cases sometimes present 

 themselves, however, in which the Hysteric paroxysm assumes the Epileptic 

 character, the larynx being closed during expiration, so as to produce alarming 

 results. The disordered state of the Nervous Centres, to which these con- 

 vulsive actions are due, seems to be peculiarly connected with Emotional con- 

 ditions of the mind, and with functional derangements of the sexual organs. 



504. The foregoing are the chief general spasmodic diseases in which the 

 Spinal system of nerves is evidently involved ;* but there are many others of 

 a more local character. Such are the various forms of Spasmodic Asthma, 

 the attacks of which generally result from some internal irritation, either in 

 the lungs themselves or in the digestive system, producing a reflex action upon 

 the muscular fibres of the bronchial tubes. The Croup-like Convulsion, or 

 Crowing Inspiration of Infants, again, is an obstruction to the passage of the 

 air through the glottis, by a spasmodic contraction of the constrictors of the 

 larynx. This spasmodic action may be induced by various kinds of irritation ; 

 such as that occasioned by teething, by the presence of undigested food, or by 

 intestinal disorder. In the crowing inspiration, the larynx is partially closed ; 

 when the spasm is severe, however, there is complete occlusion of the pas- 

 sage ; and forcible efforts at expiration are made, which induce, as in epilepsy, 

 a severe degree of venous congestion, and this reacts upon the nervous cen- 

 tres, aggravating the previous disorder of their condition. The present in- 

 creased knowledge of the functions of the laryngeal nerves, and of the symp- 

 toms of this disease, appears to render inadmissible the explanation of it given 

 not long since by Dr. H. Ley, who attributed it to paralysis of the pneumo- 

 gastric nerves occasioned by pressure. Spasmodic closure of the larynx may 

 occur from other causes. When the rima-glottidis is narrowed, by effusion 

 of fluid into the substance of its walls, it is very liable to be completely closed, 

 by spasmodic action, to which the unduly irritable condition of the mucous 

 membrane will furnish many sources of excitement. Choking, again, does 

 not result so much from the pressure of the food on the air-passages them- 



' Chorea is ranked by Dr. M. Hall as a disease of the Spinal System of nerves ; but this 

 can scarcely be regarded as a correct determination. It is true that there is considerable 

 irregularity in the ordinary Reflex actions ; but the irregularity is still greater in those, to 

 which Volition or Emotion are the stimuli. Moreover, the body is at rest during sleep ; and 

 "the Spinal system never sleeps." The frequent origin of the disease in causes which have 

 excited strong mental emotions, and the effect of even moderate excitement of the feelings 

 in greatly aggravating the movements of the body, seem to indicate the connection of this 

 disease with the Sensori-motor system of nerves. Stammering maybe regarded as a sort of 

 Chorea affecting the muscles of voice ; of this more hereafter (CHAP. TI). In Paralysis Agitans, 

 it may be usually observed, that the voluntary actions are much more affected than the reflex ; 

 the latter, indeed, not in general manifesting any disturbance. An interesting and well marked 

 case of this disease has been mentioned to the author by Dr. W. Budd, in which softening 

 was found in the Crura Cerebri. 



