42% CASES OF EXOniTHALMIC GOITRE. 



In anaemic persons, for example, where the vaso-mctor system 

 is weak and tlie arteries relaxed, the heart often heats violently, 

 especially when any additional relaxation is produced in the 

 arteries by some slight exertion. Here, no doubt, there is a 

 disproportion between the action of the heart and the work it 

 has to do. This implies a weakness or disturbance of the 

 nervous arrangement, which ought to regulate the one to the 

 other. The part of this arrangement which is in fault, how- 

 ever, seems to be the vaso-motor system, which allows the vessels 

 to dilate too much, rather than the vagi, whose function is to 

 restrain the heart. Both kinds of palpitation which I have 

 mentioned, depending as they do on a weak or paralysed con- 

 dition of the vagi or vaso-motor nerves, ought to be relieved by 

 the use of tonics ; and in fact we do find that such remedies, 

 and more especially iron, are of the utmost service in the palpi- 

 tations of anaemia. But the third cause of palpitation, viz. 

 stimulation of the accelerating nerves of the heart, depends 

 not on weakness, but on over-action of that part of the nervous 

 system, and anything that will increase its power will prove 

 injurious rather than beneficial. Now this is exactly the con- 

 dition which is found in exophthalmic goitre. Although 

 persons suffering from this disease are not unl'requently anaemic, 

 the administration of iron is not followed by its usual good 

 effects. On the contrary. Trousseau states that it increases the 

 palpitation to such an extent that its employment can rarely 

 be continued. This is exactly what we should expect on the 

 supposition that the palpitation depended on stimulation of the 

 accelerating nerves of the heart, and I am therefore inclined to 

 believe that the palpitation in exophthalmic goitre is due to 

 irritation of these nerves. Their deep origin has not been 

 exactly determined, but they pass out from the spinal cord along 

 the vertebral artery to the third cervical ganglion, and thence 

 to the heart. They might be excited by an irritation applied 

 to either, at their origin or during their course, and thus we 

 might expect them to be called into action by changes in the 

 brain, medulla, spinal 6ord, third cervical ganglion, the branches ■ 

 accompanying the vertebral artery, or those going to the heart. 

 In ordei to ascertain where the source of irritation is, we must 



