Anticipatory postural adjustment during gait initiation in multiple sclerosis patients: A systematic review.

BACKGROUND: Multiple sclerosis (MS) causes balance and walking disorders. Gait initiation is the complex transition between standing and walking and is characterized by two distinct phases: the anticipatory postural adjustment (APA) phase followed by the execution of the first step phase. RESEARCH AIM: To determine alterations in the APA during gait initiation in patients with MS. METHODS: A systematic search was conducted in May 2018. The search was carried out by the use of the following databases: PubMed, Web of Science and the Cochrane Library. The following keywords were used: MS, gait initiation, step initiation, and postural adjustment(s). Outcomes of interest were the variables generally used to assess APA, including electromyography, force-plate data, or video-based data, duration of APA, and length of first step. The Ottawa scale was used to assess the quality of the studies. RESULTS: Eight case-control studies were included; one was a transverse study. A total of 215 MS patients and 116 healthy subjects were included with ages ranging from 22 to 76 years old. In MS patients, Expanded Disability Status Scale (EDSS) scores ranged from 0 to 7. APA CoP displacements were smaller in the anteroposterior axis. Four studies evaluated muscle activation during APA. The latencies of all muscles were delayed, and smaller magnitudes of muscle activity during APA were found, even in the early stage of disease. The first step was shorter in MS patients than in healthy patients. No previous study has reported joint movement or trunk inclination during gait initiation. SIGNIFICANCE: This review illustrates the gap in knowledge of APA alterations in MS patients. APA assessment in the early stage of MS could be an interesting measure to characterize balance, dynamic control and risk of fall for such patients.

Does adolescent idiopathic scoliosis relate to vestibular disorders? A systematic review.

UNLABELLED: Adolescent idiopathic scoliosis (AIS) is a tridimensional deformity of the spinal column. This frequent disease, which has no clearly identified pathogenic mechanism, can have serious consequences. It has been hypothesized that unilateral and isolated vestibular disorders could be the origin of AIS. The objective of this work is to verify this hypothesis and to establish a pathophysiological model. METHOD: We performed a Pubmed-NCBI search, for the period 1966-2013, crossing the keyword scoliosis with the following keywords: vestibular, labyrinthine, postural control. RESULTS: This search retrieved 66 articles. Twenty controlled studies were considered for study. Their analysis showed discordant results. This review cannot confirm a link between isolated vestibular disorder and occurrence of development of scoliosis. CONCLUSIONS: There is not enough evidence to show a link between unilateral, isolated, vestibular dysfunction and AIS. From these findings, we propose a more global pathophysiological concept, which involves a trouble of the orthostatic postural control, with disturbance in the multisensory integration of vestibular, visual and somesthesic inputs. AIS could be the consequence of a reorientation of the longitudinal body axis in accordance with an erroneous central representation of verticality. An assessment of the sense of verticality would allow evaluate this hypothesis.