K. Jamal

Effect of sensorial stimulations on postural disturbances related to spatial cognition disorders after stroke

Balance disorders related to disturbances in perception of spatial reference systems are common especially after right hemispheric stroke. Mental misrepresentation of bodily orientation in space is then often superimposed upon other factors affecting imbalance such as motor and sensory impairments. Traditional rehabilitation for balance recovery has not been specifically designed to improve balance disorders related to spatial cognition. The traditional approach, consisting of stimulating the conscious perception of body orientation in space, is demanding and laborious. The approach based on sensorial stimulation is completely different. The relevance of this method lies in the fact that, firstly it is specifically active in the cognitive component of balance disorders; and secondly, it can passively be applied with minimal patient participation, which is of particular importance for this patient group characterized by disorders of attention and concentration. These techniques, such as proprioceptive, visual or vestibular stimulation, have been found to correct spatial neglect but also postural bias. Clinical and data from functional neuro-imaging suggest a direct central action on cortical structures involved in the elaboration of spatial representation. These are promising techniques for the rehabilitation of postural disturbances related to spatial cognition disorders but are as yet at the stage of preliminary results.

Effect of neck muscles vibration on postural balance and spatial frame of reference: A systematic scoping review

Introduction/Background Muscle vibration, in particular applied to the neck muscle is increasingly being used as a mean of rehabilitation treatment. Neck muscle vibration (NMV) is thought to have an effect on the representation of the body in space through sensory recalibration. The objective of this systematic scoping review was to map out the characteristics of the existing studies and gather the effect of neck muscle vibration on both spatial frame of reference and on postural balance. Material and method following the PRISMA guidelines, a systematic search was carried out using the databases MEDLINE, EMBASE, Cochrane library and PEDrO applying the following key words [(Postural balance) OR (Spatial reference)] AND (Neck muscle vibration) for those articles published through to July 2016. Results Altogether 67 studies were assessed and they unveiled both a large heterogeneity and a standard quality of methodology with a total of 1522 participants included. Under unilateral neck muscle vibration, the visual environment (illusion of a visual target) seemed to move towards the opposite side of the vibration, and both the visual vertical and the straight ahead were shifted towards the vibrated side. In addition, NMV produce a body tilt. This effect is however not constant at all times. Conclusion NMV is considered as a useful remedy tool in rehabilitation therapy which has shown to induce a body sway on the force platform and a deviation of the spatial representation in both healthy subjects and patients. That said, however, owing to the heterogeneity of the experiences and the various significant shortfalls highlighted, this research does not allow us to firmly conclude our results.