EXAMINATION OF THE NERVOUS SYSTEM 233 



the electrode is put on it, by a quick quiver. In a degenerated or atrophied 

 muscle, the reaction is a slow vermicular cjuiver or in old cases where 

 the paralysis has existed for a long time there may be no motion at all. 

 The constant or open current will frequently stimulate muscular con- 

 traction, when the faradic current will give no movements whatever. 

 AMien degenerative muscular atrophy has set in for any length of time 

 no reaction can be obtained from either current. For further details 

 see special work on this subject. 



The most important test of paralyzed muscles is their size. In all 

 cases of prolonged paralysis the muscles atrophy ciuickly. The muscle 

 gradually becomes smaller and smaller until it resembles a cord or tendon. 

 In cerebral paralysis this does not occur, while in spinal paralysis it is 

 always present. Of course, in some instances an inactive muscle will 

 atrophy without any actual disease being present. The amount of 

 atrophy which may occur in certain cases is indicated by a communication 

 given to the author l^y Goubaux. In this instance the paralyzed anterior 

 limb of a dog weighed 103 grammes, while the perfect limb weighed 148 

 grammes. 



Convulsions. — Convulsion of the controlling muscles is the very 

 opposite of paralysis. Convulsions are diseased contractions of the 

 muscles which are independent of the will. There are several varieties 

 of them. Clonic convulsions are short muscular contractions that occur 

 at intervals, and between the intervals the affected portion of the body 

 quivers constantly. Tonic convulsions are muscular contractions in 

 which the muscle remains constantly contracted. It may occur for a 

 minute or two, or may last several days. Tonic clonic convulsions are 

 the medium form of the two conditions before described. A mild form 

 of clonic contractions is noticed in the original muscular twitchings. 

 Trembling and shaking convulsions, seen in chill, fear, or sudden cooling 

 after being very warm, epileptiform convulsions, or eclamptic convul- 

 sions, are seen and extend over the whole body. In very rare instances 

 they may be restricted to one portion, such as the head or neck. These 

 generally come on suddenly and disappear in a few minutes. They 

 are generally seen in the early stages of distemper, in teething, in 

 irritated conditions of the bowels, or from noxious and poisonous food 

 and from parasites; in cases of pentastomum in the nasal cavities, in 

 encephalitis, meningitis, or uremia, and occasionally in acute ansemia; 

 they also occur from some injury or irritation of the peripheric centres, 

 and are very prominent in epilepsy. Rhythmic twitchings are seen in 

 some muscular regions where the afTected part of the body makes regular 

 motions; for instance, in the muscles of mastication, in the muscles of 

 the chest during sleep, and also in the twitching of certain limbs. They 

 are very often mistaken for chorea, and appear as a result of distemper 



