Apraxia

The apraxia is a Clinical sign which describes an incapacity to carry out a movement or a series of movements on instruction. This or these movements in addition are well carried out spontaneously. It is a neurological deficit which is at the level of the conceptualization and the programmed execution of a movement. The driving and sensitive functions basic which allow this or these movements must be intact.

The word apraxia rises from the term Praxie which indicates the functions of coordination and adaptation of the basic voluntary movements with an aim of achieving a given task. Praxie comes from the Greek word praxis which means action .

Various types of apraxia:

  • the apraxia idéatoire is regarded as a disorganization of the mental representation of the gestures to carry out. It is impossible for the patient to carry out a movement made up of a whole of organized elementary under-movements. From a driving point of view, the elementary movements are well carried out, but the idea of the gesture is incoherent. This pathology deteriorates mainly the activities of handling of objects and use of tools.

  • the apraxia idéomotrice is characterized by the incapacity to carry out a gesture on request, while the spontaneous execution is possible (dissociation automatico-volunteer). The apraxia idéomotrice is sometimes associated with a Aphasie which is a deterioration of faculty to be expressed and/or include/understand the oral language and/or writes whereas the bodies of the word and the sensory systems implied (hearing, sight) are intact.
  • the driving apraxia is characterized by the incapacity to carry out precise movements. The driving sequence necessary to the realization of a fine movement is faded.
  • the constructive apraxia is a visuo-space disorder which results in a difficulty of defining the relations of the objects between them. It is often associated with a aphasia of Wernicke.
  • the apraxia of the walk results in an impossibility of the patient to suitably lay out his legs to go.
  • the apraxia of the preparing is characterized by an impossibility of dressing itself correctly.
  • the apraxia buccofaciale (or " bucco-linguo-faciale") results in an incapacity of the patient to whistle, blow or carry out any other type of movement implying the mobilization of muscles located at the level of the face (in the broad sense of the term).
  • the reflexive apraxia is characterized by impossibility to carry out movements bimanuels without significance (mimes).
  • the dynamic apraxia results in a disturbance of the sequence of the gestures

Relation between cerebral and standard lesion of apraxia

  • Apraxia idéatoire: gyrus angular (parietal cortex)

  • Apraxia idéomotrice: gyrus supra-marginalis (parietal cortex)
  • left Apraxia unilateral idéomotrice: former third of the callous body
  • driving Apraxia: driving cortex (surfaces 4 and 6 of Brodmann)
  • constructive Apraxia: parietal cortex
  • Apraxia of walk: gyrus frontal superior (frontal cortex)
  • Apraxia of the preparing: gyrus supramarginalis (parietal cortex)
  • bucco-linguo-facial Apraxia: cover fronto-rolandic (frontal cortex)
  • reflexive Apraxia: frontal cortex
  • dynamic Apraxia: frontal pre lesion.

Apraxia and models of the movement

When a voluntary movement is carried out, the requested cognitive mechanisms can be schematically modelled in three great stages: the " representation mentale" gesture to be realized (planning), programming of the movement and the request of the muscles necessary to the movement (in the good order). The principal forms of apraxia result from the deterioration of the one of these three stages:

  • the deterioration of the representation of the movement, process during which the movement is conceived, results in the apraxia idéatoire;

  • the deterioration of the stage of programming of the sequence of muscular contractions necessary to the movement results in the apraxia idéo-motor coach;
  • the deterioration of the stage of setting in motion of the muscles results in the driving apraxia. The latter can be subdivided in kinesthetic apraxia and Mélokinétique apraxia.

Treatment

Forecast

Reference

  • Courteous G., Neurology, 2003, Gaëtan Morin editor ltée (Boucherville).
  • Apraxia. Solal Editions
  • Tool uses and mechanical problem solving in apraxia. (1998) Neuropsychologia, 36,581-589.
  • Gil R., Neuropsychology, Masson, Paris, 2006, 4th edition. ISBN 2-294-01923-7
  • Morlaas Joseph, Contribution to the study of the Apraxia. Paris, A. Legrand, 1928. (Available to the BNF)

External bonds

  • “gestural apraxia. Parts Theoretical & Experimental”: Thesis of Philippe Peigneux

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