NEURALGIA. 



321 



Except in the cases resulting from malaria, the course of the dis- 

 ease is chronic. It is rarely regular, the individual attacks are marked 

 by paroxysms of pain interrupted by free intervals, and in the general 

 course of the disease we are apt to see remissions and exacerbations. 

 At times the attacks of pain are more frequently repeated and are 

 more severe, at others, they return less frequently and are less severe. 

 It is only in the neuralgia caused by malaria, in the so-called febris 

 intermittens larvata, that the paroxysms of pain show a regular type. 

 In other cases the type is irregular, and the attacks not only recur 

 spontaneously, that is without assignable reason, but they are excited 

 by various recognizable causes. Among these are irritation of the 

 skin which the affected nerve supplies, by pressure, friction, cold, heat, 

 etc. Slightly touching the skin often appears to induce attacks of 

 pain more readily than heavy pressure does. Movements of the parts 

 where the pain is located, i. e., chewing in neuralgia of the trigeminus, 

 walking in neuralgia of the sciatic, coughing and sneezing in that of 

 the intercostals, excite attacks of pain. Mental excitement occasion' 

 ally has the same effect. I treated one old gentleman, with neuralgia 

 of the trigeminus, who had such a severe attack of pain every time I 

 entered his room, that he could not salute me for some time. Each 

 attack of pain usually lasts only a few seconds. But these short at- 

 tacks are often repeated several times in the course of one or a few 

 minutes, and then cease for a while, so that in fact we may say that 

 in neuralgia long attacks occur which are composed of a number of 

 short paroxysms. As we are almost compelled to believe that the 

 irritation acting, on a nerve, which causes the neuralgia, acts continu- 

 ously, the intervals between the pains appear enigmatical : for their 

 explanation we must refer to the physiological fact that the severe 

 irritation of a nerve exhausts its excitability for a time ; then in neu- 

 ralgia, states of great excitement would alternate with states of dimin- 

 ished excitability. This hypothesis is to some extent supported by 

 the observation that, after severe attacks of pain, the peripheral ter- 

 minations of the nerve are for a time less sensitive to irritation, as ii 

 their excitability were diminished, as well as by the observation that, 

 after inducing a severe neuralgic attack by continued pressure on a 

 painful point, a repetition of the pressure does not induce a second 

 attack. The gentleman above mentioned also had attacks of pain as 

 soon as he began to eat. In order that he might be able to eat at 

 meals, he began them by biting vigorously on some hard bread ; this 

 induced a severe attack, but after it passed over he remained free from 

 pain during the remainder of the meal. 



Neuralgia may continue for many years. Except in the oases 

 caused by malaria or the so-called rheumatic neuralgia, complete cure 



