Validation Study of SCALA, Scale for Lateropulsion (SCALA)

Development and clinical validation of SCALA, a new rating scale for lateropulsion after stroke. A monocentric clinical study including 78 post-stroke individuals and 30 patients without stroke and/or healthy volunteers. In order to analyze the SCALA's content validity, a Delphi-type consensus process was applied prior to clinical validation. The Delphi process, including 20 international experts, has given rise to the version of the scale to be tested clinically (SCALA-V1; Paper in preparation).

The protocol aims to develop and validate a new clinical rating scale assessing lateropulsion after stroke. The project is driven by the need to have a tool that better meets clinometric properties than the 2 main existing scales, the Scale for Contraversive Pushing (SCP) and the Burke Lateropulsion Scale (BLS), and by the need to have a unicist scale to assess all components of lateropulsion (i.e. body tilt, active pushing by non-paretic limbs and resistance to passive correction) regardless the mechanisms or the severity of lateropulsion and the side of the stroke lesion. The initial version (version 0) of the scale has been developed by our team in Grenoble (SCALA-V0). In a first step, an online expert consensus process (Delphi method) will give rise to a version 1 (SCALA-V1), considered as generally accepted by the scientific community. The SCALA-V1 will be validated in a monocentric clinical study. 78 individuals with stroke and 30 individuals without stroke and/or healthy controls will be included. All subjects will be comprehensively assessed during 3 weeks. During the first week will be performed many assessments used in routine in our center. These assessments will serve to describe participants and ensure that our series is comparable to others of the literature. These assessments which are not considered as outcome are: age, sex, height, weight, manual laterality, comorbidity, apraxia, executive function deficits, retropulsion, depression, and autonomy. Several other clinical assessments will also be performed during the first week, this time to serve as outcomes: stroke lesion characteristics, motor weakness, spasticity, spatial neglect, anosognosia, aphasia, hemianopsia, hypoesthesia, visual verticality, balance and gait disorders. During the second week, lateropulsion by SCALA-V1, verticality perception and spatial representation will be assessed to determine their inter-rater reliability. During the last week, mass distribution on lower limbs in frontal plan during standing position and body orientation in frontal plan during sitting position, standing position and sit-to-stand will be assessed. Editorial valorization of the clinical trial: This study will be valorized by several papers, one concerning clinometric properties of SCALA-V1 (reliability …), other(s) paper(s) about the understanding of lateropulsion, and clinometric properties of the devices assessing vertical perception and body orientation.

This study is a monocentric observational clinical study. During the first week, the assessments used in routine in our center will be performed. During the second week, the assessments of lateropulsion by SCALA-V1, postural verticality perception in sitting and the representation of longitudinal body axis in lying position will be performed twice, 2 days apart, by 2 different raters in order to determine their inter-rater reliability. During the third week, mass distribution on lower limbs in frontal plan during standing position and body orientation in frontal plan during sitting position, standing position and sit-to-stand will be assessed.

Comparison of proportion of individuals with a lateropulsion by using the total score of SCALA based on all items (with and without vision) and that of individuals with a lateropulsion by using the total score of SCALA based only on items with vision

Influence of sensory-motor, language and cognitive deficits, severity of balance and gait disorders, and stroke features (type and localization) on the time required to complete SCALA; Descriptive statistics on items judged as "not applicable"

Relation between the total score or subscores of SCALA, and stroke lesion characteristics, verticality perception, representation of longitudinal body axis in lying position, body orientation in frontal plan, weight-bearing asymmetry, and awareness of deficits.

Comparison to Scale for Contraversive Pushing and Burke Lateropulsion Scale, which currently are considered as gold-standards to assess lateropulsion.

Inclusion Criteria: All types of stroke, ≤6 months. Exclusion Criteria: postural disorders other than stroke or body geometry disorders (e.g. limb amputation, severe deformity, bone fracture, trunk deformity with deviation of C7 greater than 30mm) interfering with balance, acute vertigo, history of severe psychiatric disease, medical instability, dementia diagnosed, and severe understanding deficits limiting assessments.