1692 



II Wlllii ir iK I IF l-ms 'i 



NEUROPHYSIOLOGY III 



the goal that he proposes or which is proposed to 

 him. The subject is perfectly aware of the objective 

 in be attained and of the movement to be carried out, 

 but he is impotent in controlling its correct execu- 

 tion. He realizes his error hut cannot correct it. He 

 astonishes and irritates himself because of it. 



This form of apraxia affects especially the gestures 

 of symbolic character; pointing with the linger in a 

 direction, making the sign of the cross or executing 

 the military salute are generally impossible to execute 

 correctly. In the same way, descriptive gestures, in 

 the absence of the appropriate setting, are particu- 

 larK disturbed. Generally, as stressed by Lhermitte, 

 the less a gesture offers in the way of pragmatic value, 

 the less directly it is related to instinctive or emo- 

 tional life, the more it is altered in apraxia (74). 



I he special feature oi this type of apraxia is the 

 fact that the movement which is impaired can be 

 carried out in a perfectly adapted fashion when the 

 patient is under the influence of an emotional ex- 

 perience at a time when ii may be incorporated in an 

 involuntary automatism. For instance, he may make 

 the sign of the cross upon entering a sanctuary. The 

 kinetic formulas for the gesture are intact and can 

 still be mobilized in the frame of an automatic 

 reaction. It is therefore essentially the intentional use 

 of these mechanisms which is impaired. 



As Alajouanine pointed out, ""The disordered 

 gesticulation of apraxics evokes the idea of an in- 

 voluntary automatism deprived of control" (4). This 

 author insists also on what he calls the syndrome of 

 'automation oluni.u \ dissociation' which approxi- 

 mates the aphasia of W'ernike (abolition of the 

 volitional use of language), an aphasia which is 

 therefore a form of idiokinetic apraxia. It must be 



distinguished from certain aphasias of Broea in 

 which the automatic use also often disappears for 

 certain categories of words only. We can evidently 

 conceive here of an affection of the specific kinetic 

 formulas, as in motor apraxia. 



This form ol apraxia is encountered usually with 



.1 lesion of the cortex predominant!) in the region 

 ol the second parietal convolution at the extremity 

 11I the Sylvian fissure and involving the region of the 

 mpramai ginalis g) 1 ns 



These observations should lead to the belief that 

 .1 1 Ins,- relationship exists between the regulation of 

 gestural functions and the data relative to the per- 

 ■ eption Hi space both in the bod) and in the environ- 

 ment. 



We owe to Head (46) the first accurate ideas 

 ■ erning the importance of the integrit) of the 



body scheme for motor behavior. Today, we know 

 that the body represents a frame of reference upon 

 which our knowledge of surrounding space is then 

 constructed. It is in this external space and toward 

 the objects that it contains that we direct our acts. 

 Schilder (106) accurately described the building; of 

 the body scheme on the basis of kinesthetic, laby- 

 rinthine, tactile and visual impressions. These im- 

 pressions form, in a constantly remodeled structure 

 embodying the data of the moment with those of 

 past experiences, a dynamic integration which pro- 

 vides our acts and our perceptions with the special 

 frame in which they acquire their significance. 



In our ascending search for the origins of the 

 patterning of the motor commands, we are thus led 

 to leave the field of motor integration and to draw- 

 progressively nearer the field of sensory integration. 

 We are brought therefore to consider the conse- 

 quences on motor activity of certain disturbances ol 

 perceptive integration. The gnostic and praxic 

 defects are usually so interlaced that some authors 

 like Grunbaum (44) find it difficult to distinguish 

 between them in a generalized disorder. From this 

 standpoint, it should therefore be better to speak of 

 'apractognosia.' Liepmann already clearly dis- 

 tinguished this category of gnostic deficiency dis- 

 orders and put them in the category of 'parapraxia 

 by agnosia.' 



The relation of certain forms of apraxia to visuog- 

 nosic disorders has been shown in the 'constructive 

 apraxia' described by Foppelreuter (99). The subject 

 is incapable of constructing symbolic or other kinds 

 of geometrical figures graphically or with the help 

 of concrete objects 



The relation between the disorders of somatognosia 

 is ie\e.iled ill the "apraxia lor dressing' described by 



Brain (16). It corresponds, as was shown In Hecaen 

 & Ajuriaguerra t^Bi, to a lesion of the minor hemi- 

 sphere with hemiasomatognosia. 



Tin. ill\ let us mention the localized disorder asso- 

 ciated with a digital agnosia and expressing itself 

 iii the complex 'syndrome of Gerstmann.' It is ac- 

 companied by acalculia and corresponds to .1 lesion 

 of the dominant hemisphere 1 49). 



We nuw appreciate Hie variet) and intricacy of 

 the symptoms oi these disorders and the difficulties 

 of interpretation which result therefrom. Perhaps 

 there i^ reason to reserve a special place for the 



forms of disturbance which .ire caused not b\ a 



direct impairment ol the gnostic areas, but by the 

 rupture of die connections which relate certain 

 tactile, kinesthesic or visual representations to the 



