Static and Dynamic Postural Stability in Cerebral Palsy Children
Condition: CP (Cerebral Palsy); Diplegia; Hemiplegia; Postural; Defect
MeSH terms: Paralysis; Cerebral Palsy; Hemiplegia
Study type: Interventional
Phase: Phase 3

Summary: 
      Cerebral palsy (CP) concerns 2 children out of 1000 in the general population (SCPE 2002). It
      is the main cause of postural and motor deficits in children.

      During the past 20 years, the postural deficits exhibited by these children have been
      attributed to various factors :

        1. neuromuscular functions

        2. sensory integration

        3. muscular-squeletic functions.

      The common point of all these studies is the existence of immature motor patterns, probably
      related to an inability to implement more elaborated and adapted motor patterns with respect
      the task to perform.

      CP children do not develop the characteristics of the plant grad locomotion. They exhibit a
      uniform muscular activation with a high level of co-activation. Locomotion is generally
      characterized by an increase of stretching reflexes at short latencies and by a low level of
      activation associated to a low modulation of gastrocnemius muscles..

      These data also suggest that it is the control of the temporal rather than the spatial
      parameters of the head which are mainly altered in CP children.

      Even though static postural control and locomotion are considered as automatic processes,
      this control requires, however, a significant amount of attentional resources.

      Within this context, the amount of attentional resources which need to be solicited can
      provide information on two complementary dimensions. On one hand, on the level of
      automaticity of postural control and/or locomotion when subjects' attention is oriented
      toward another task. On the other hand, on the cognitive cost of postural control and/or
      locomotion, depending on children age, that is, as a function of their level of maturation
      and of the nature and importance of their sensory-motor deficits. When the amount of required
      attentional resources is reduced, postural control and/or locomotion is considered as
      automatic processes with a low cognitive cost.

      The dual task paradigm in which subjects have to simultaneously process a cognitive (e.g.
      Stroop task) and a postural or motor task (e.g., standing upright on a force platform) is
      generally used to investigate these questions.

      How an appropriate allocation of attention is performed as a function of the cognitive and
      postural/motor tasks is important in the developmental process of posture and locomotion. It
      seems to be even more crucial in CP children and more generally in pathology.

      The main goal of the present project is to investigate the contribution of attentional
      processes in postural control and locomotion of CP children as compared to control healthy
      children.
    

Detailed description: 
      Within this scientific and clinical context, we hypothesize:

        -  That CP children will be less stable than healthy children (in control situation) and
           that the attentional cost for controlling static posture will be higher.

        -  On the basis of Olivier et al.'s work (2008) showing in adults and children aged 4 to 11
           that postural control is better when attention is oriented toward a video film (i.e.,
           decrease of the attentional demand allocated to the control of static posture), we
           predict that CP children will be more stable in dual task situation with visual or sound
           distractors than when focusing attention on postural control alone.

        -  We also predict that an additional cognitive task (adapted Stroop task), by increasing
           the attentional demand, will induce a deficit of postural control confirming Reilly et
           al.'s results (2008b).

      On the same basis, we will also investigate the attentional cost of locomotion.

      Exploratory study of dynamic equilibrium during locomotion in the same conditions.

      Investigation of posture in the following conditions:

        1. without attentional distractors and without additional cognitive task (control
           condition)

        2. with attentional visual and sound distractors (video film)

        3. with sound attentional distractor alone (sound track of the video film)

        4. with an additional cognitive task (Stroop task adapted for children).

      Considering the goals of this research project, no serious undesirable event is expected to
      occur. However, falls may occur accidentally while rising or descending from the force
      platform, during static posture, or during locomotion. Consequently, in addition to the
      experimenter, a physiotherapist or someone of the medical staff will be present during all
      experimental recordings.

      The environment will be also organized to the secure the experimental room by excluding all
      potentials dangerous or non necessary objects. Whenever necessary, the potentials falls will
      be reported and declared to the health authorities.
    

Intervention name(s): no distractor control group; visual and sound attentional distractors; sound attentional distractor alone; additional cognitive task
Intervention type(s): Procedure; Procedure; Procedure; Procedure
Intervention description(s): This control condition will aim at analyzing posture and locomotion in CP children with the intent to focus attention on their equilibrium, only, without any other interference.; The distractors will be used to orient subjects' attention toward another simple and motivating task in order to avoid focalisation on postural control and locomotion and to favour a more automatic control.; In addition to the previous condition, the goal of the present condition is to isolate the effects of a sound distractor, since it is known that CP children frequently exhibit visual deficits which may affect their postural and locomotion difficulties.; The additional cognitive task aimed to increase the attentional load and to analyse its impact on children's capacity to process two tasks simultaneously (the cognitive and postural or locomotor tasks)
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Supportive Care
Keywords: Locomotion; cerebral palsy; Postural; Defect