458 PHYSIOLOGY CHAP. 



exceedingly rare"; more frequently there is an irresistible tendency 

 to incline sideways or backwards, with curvature of trunk or neck, 

 strabismus, nystagmus, etc., so that the patient is incapable not 

 only of walking, but also of holding himself upright. 



Cases of cerebellar tumours are not infrequently complicated 

 by epileptiform attacks, which may be general and widespread, as 

 in ordinary epilepsy, or partial and limited to certain groups of 

 muscles, as in Jacksonian epilepsy. But in cerebellar atrophy of 

 long standing these epileptiform fits are even more frequent; 

 epilepsy cannot therefore be purely and simply the effect of 

 compression exerted by the tumours. 



In tumours with a rapid course this complex of symptoms 

 predominates, and partly or wholly masks the fundamental 

 phenomena of cerebellar deficiency. But in most cases the 

 asthenic, atonic, and astatic symptoms described in animals that 

 have lost part or the whole of the cerebellum are associated to a 

 greater or less degree with symptoms due to compression or 

 irritation of the adjacent organs. 



With the exception of cases of agenesia and partial atrophy 

 with a slow course which may remain entirely latent, the gait in 

 the vast majority of cases of cerebellar disease due to large or small, 

 symmetrical or asymmetrical lesions (tumours, haemorrhagic foci, 

 abscesses, etc.) is what clinicians term staggering, uncertain, and 

 reeling like that of the slightly inebriated this is the synthetic 

 expression of cerebellar ataxy. As in a drunken person, the 

 oscillations of the body and continual irregular displacements of 

 the centre of gravity represent the effects of functional deficiency, 

 while the separation of the feet in walking, the inclination to left 

 or right, the hurried step forward or stumble back, and the use of 

 the arms as a counterpoise, are compensatory acts intended to widen 

 the base of support, lower the centre of gravity, and re-establish 

 equilibrium which is threatened in one direction or the other. 



In asymmetrical or unilateral lesions of the cerebellum the 

 tendency to fall is in the majority of cases towards the side of the 

 lesion (seven times out of ten, Adler) ; in bilateral symmetrical 

 lesions the tendency is usually to fall backwards. Exceptions to 

 this rule, while conflicting from the clinical point of view, have no 

 scientific value. 



One important clinical result is that the motor disturbances in 

 cerebellar patients are always far more marked in the lower limbs 

 than in the upper as is the case to a marked extent in animals. 

 In rare cases there is a certain amount of ataxia in the upper 

 limbs, which is shown in an incapacity for carrying out delicate 

 movements with the hands. 



Still more important is the fact clinically noted by Nothnagel, 

 Monakow, and others that in cerebellar patients the ataxy of the 

 lower limbs disappears completely when the patients are lying in 



