CEREBELLAR SYMPTOMS LN HUMAN DLSEASE. 901 



The difference between the effects of Magendie's and of Longet's sections 

 is not one of mere description. Magendie's section implicates especially the 

 posterior part of the pons, and Longet's especially the anterior ; the explanations 

 offered by Schiff : and Longet 2 do not appear to me satisfactory. 



Suppose the right peduncle cut. The animal bends its neck toward 

 the right shoulder, its chin toward the left (as though the left sterno- 

 cleido-mastoid muscle had been paralysed), the right shoulder is turned 

 toward the breast, the left toward the back, and thus the cephalic 

 half of the animal has turned through an arc of about 90° on the 

 pelvic half. This is so long as the animal rests quiet ; when it tries 

 to move, the torsion of the body is converted into actual revolution 

 about the long axis. The rate of rolling has been described to be 

 as high as fifty turns a minute. It may persist for days, but gradually 

 passes off; it leaves a permanent inability to turn the head to the left 

 (Lussana). 3 



With the rolling and ocular deviation usually coexist incurvation of 

 the trunk to the side of the lesion, some lateral nystagmus, adduction 

 and ataxy and tremor of the homonymous limbs, abduction of the crossed 

 limbs. In the dog and rabbit the limbs are extended, but in the monkey 

 the homonymous limbs are flexed (Ferrier and Turner). 4 



Section of the posterior peduncle.— This experiment has been 

 practised very frequently from the time of Eolando 5 and Magendie 6 

 onwards, and there exists little or no discrepancy in the observations. 

 The phenomena ensuing are incurvation of neck and trunk to the side of 

 the lesion, falling to that side, deviation of the eyeballs from that side ; 

 adduction of the homonymous limbs, with ataxy and tremor in them ; 

 abduction of the crossed limbs ; tendency to roll toward the side of the 

 lesion, and some twisting of the head, so that occiput points to lesion, 

 chin in the direction of the eyes. Ferrier and Turner, 7 the only observers 

 who have employed monkeys, noted in that animal tonic flexion in the 

 homonymous limbs, tonic extension in the crossed ; but this characteristic 

 position was not so persistent as incurvation of trunk, tendency to roll, 

 and tremor on movement. 



Bilateral section of the peduncles. — It has been shown by many 

 observers, e.g. Magendie, Lussana, that the rolling movement ensuing on 

 section of one peduncle can be cut short by a symmetrical section of 

 the opposite peduncle. 



Phenomena of cerebellar origin in human disease.— On turning 



to the symptomatology of cerebellar disease for help toward the understanding 

 of the functions of the organ, we find that the clinical material must he 

 much sifted, to yield secure data for the purpose. No detailed attempt of 

 that kind can have space here. But the following can he said : — A reeling 

 gait, oscillations of the body which may impart a zigzag direction to the walk, 

 difficulty in standing upright owing to unsteadiness of limb, are common 

 phenomena in cerebellar disease. Occlusion of the eyes does not augment 

 the unsteadiness or "reeling," hence there is no "Romberg's sign." The arms 

 are less unsteady than the legs, but the handwriting is shaky. Sometimes 

 there is swaying of the head, and very usually a peculiar " scanning " quality 

 of speech, in which the syllables come haltingly evolved. Giddiness may be 



1 "De vi motoria baseos encephali," etc., Francofurtum a/Main, 1845. 



2 Loc. tit. 3 Loc. cit. 4 Loc. cit. 5 Loc. cit. 



6 Loc. cit., and " Lemons sur la physiol. du systeme nerveux," Paris, 1841, tome i. p. 261. 



7 Loc. tit. 



