374: DISEASES OF THE PERIPHERAL NERVES. 



} T et, at the time when the palsy is called an essential palsy, all such 

 processes have long since subsided, and it is not the primitive disease, 

 but the paralysis and its consequences, that we have to treat. Essen- 

 tial palsy as a rule is the permanent product of a very acute process ; 

 for all observers agree that the affection develops within a few hours, 

 and that it never extends from the limb first attacked to the other 

 limbs. 



The causes of the disease are as obscure as is its pathogeny. It 

 occurs almost exclusively among children during the period of denti- 

 tion, and for a short time afterward ; that is, from the sixth month to 

 the third year of life. Girls and boys are equally liable, as are also 

 scrofulous and cachectic subjects, and those previously robust. The 

 assigned causes have been the acute exanthemata, and cold, especially 

 allowing children to sit upon cold stones. The latter idea is unworthy 

 of attention, as innumerable children sit daily upon the stones, while 

 essential palsy is not at all a common disease. 



SYMPTOMS AND COURSE. In many instances the attack commences 

 with febrile symptoms, and signs of cerebral hyperaemia or meningitis. 

 Mental excitement, convulsions, loss of consciousness, gnashing of the 

 teeth, are common to this, as well as to the other two maladies above 

 mentioned; and as in such cases it often happens that it is only by 

 the course of the disease that we can decide whether we have a me- 

 ningitis or a cerebral hyperaemia to deal with, so here, too, we have no 

 means of distinguishing the primary stage of an essential paralysis 

 from that of hyperaemia of the brain, save that, after subsidence of the 

 convulsions and return of consciousness, a total paralysis of one or 

 more extremities remains. Sometimes one foot, sometimes one hand 

 is affected, sometimes both lower extremities ; but it never happens 

 that both extremities of the same half of the body are paralyzed, a fact 

 which very plainly implies the independence of the disease from cere- 

 bral apoplexy or encephalitis. The bladder and rectum never take 

 part in the palsy. A mode of commencement of the malady, which is 

 scarcely less common than that by violent cerebral symptoms, consists 

 in an undefined attack of feverish symptoms, during which, without 

 precursory convulsions or stupor, an arm, or leg, or both legs, suddenly 

 hang useless, and are entirely incapable of voluntary motion. 



The subsequent course of the disease may vary. Sometimes the 

 palsy disappears in a day or two, and the disease ends in complete 

 recovery. Seine, who indisputably has seen the largest number of 

 cases, doubts whether such examples (to which the name " temporary 

 infantile palsy " has been given) proceed from the same causes which 

 give rise to the stationary, permanent essential paralysis. Duchenne 

 noticed that, in recent cases of the temporary form, the electric con- 



