232 NEUROLOGY 



It is to the clear insight of Hughlings Jackson 1 that we owe some 

 of the most fruitful suggestions as to the mode in which symptoms 

 of disease arise when the normal balance between the various func- 

 tions of the nervous system has been broken. New light has been 

 thrown on many of the phenomena of which he speaks by the phy- 

 siologists who have worked on the vast subject of inhibition, and 

 the effects of a disturbance of the interplay between inhibition 

 and excitation. The names of Meltzer, 2 Sherrington, Biedermann, 

 and Wedenski 3 come to mind, especially, in this connection. Never- 

 theless, the fundamental principles which Hughlings Jackson so 

 long ago expressed retain for the most part their validity. He 

 made it clear that the signs and symptoms met in disease are of 

 dual origin, that portion of them which is due to a lesion such as 

 we might expect to demonstrate anatomically being often the less 

 conspicuous part, while the more conspicuous part is due to the 

 vital energy of the uninjured remainder of the nervous system, 

 acting without due control and yet with reference to such coordina- 

 tion as is still in force. Special and reciprocal coordination of this 

 sort exist between the cerebellum and the cerebrum, so that the 

 special tensions and characteristics of either one is liable to come 

 singly or preeminently into play when the activity of the other 

 suffers a check. The disorders thus set up form "complementary 

 inverses" of each other. Similarly, when any portion of the nerv- 

 ous system is damaged, there are signs of defect, or "negative 

 symptoms," due to impairment of the more highly coordinated 

 functions of the part concerned and related parts, and signs of over- 

 action, or "positive symptoms," due to uncompensated activity 

 of the functions of "lower levels." 



These "positive symptoms" might be classified simply as if due 

 to unchecked liberation of energy, or as attempts at compensa- 

 tion (in a duly qualified sense) on the part of the organism as a 

 whole. Sometimes the phenomena which seem at first glance to 

 bear the stamp of "disease" are really better classifiable as of con- 

 servative or compensatory nature, while under other circumstances 

 the reverse may also be the truer statement. Thus Strohmeyer 4 

 has pointed out how "compulsive ideas" may sometimes have a 

 value for the mental health of the patient, and Hughlings Jackson 

 has suggested an explanation for the fact that motor convulsions, 

 in epilepsy, may, at least, be less injurious for the mental con- 



1 The first lecture of "Hughlings Jackson Course," delivered in January, 1898, 

 contains a brief outline of the importance of his generalizations. (Lancet, January 

 8, 1898.) 



2 Med. Rec., June 7, 1902. "The Role of Inhibition in the Normal and Some 

 of the Pathological Phenomena of Life, and Other Papers." 



' Pfluger's Arch. f. d. ges. Physiol, 1900. 



4 "The Conception of Compulsive Ideas as a Safeguard Neurosis" ("Abwehr- 

 neurosen"), Cbl. f. Nervenheilkunde u. Psych., vol. xiv, 1903. 



