Adapting a measure of gross motor skills for individuals with CDKL5 deficiency disorder: A psychometric study

J M Saldaris; P Jacoby; E D Marsh; B Suter; H Leonard; H E Olson; R Rajaraman; E Pestana-Knight; J Weisenberg; D Price; C Drummond; T A Benke; S Demarest; J Downs

doi:10.1016/j.eplepsyres.2024.107287

Adapting a measure of gross motor skills for individuals with CDKL5 deficiency disorder: A psychometric study

Epilepsy Res. 2024 Feb:200:107287. doi: 10.1016/j.eplepsyres.2024.107287. Epub 2024 Jan 15.

Authors

J M Saldaris¹, P Jacoby¹, E D Marsh², B Suter³, H Leonard¹, H E Olson⁴, R Rajaraman⁵, E Pestana-Knight⁶, J Weisenberg⁷, D Price⁸, C Drummond¹, T A Benke⁹, S Demarest¹⁰, J Downs¹¹

Affiliations

¹ Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia.
² Division of Child Neurology, Children's Hospital of Philadelphia and Departments of Neurology and Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
³ Department of Pediatrics & Neurology, Baylor College of Medicine, Houston, TX, USA.
⁴ Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Boston, MA, USA.
⁵ UCLA Mattel Children's Hospital, Los Angeles, CA, USA.
⁶ Cleveland Clinic, Neurological Institute, Cleveland, OH, USA.
⁷ St. Louis Children's Hospital and Washington University School of Medicine, St Louis, MO, USA.
⁸ NYU Langone Health and Department of Neurology, New York University, New York, NY, USA.
⁹ University of Colorado, School of Medicine, Depts Pediatrics, Neurology and Pharmacology and Children's Hospital Colorado, Aurora, CO, USA.
¹⁰ University of Colorado, School of Medicine, Depts Pediatrics, Neurology and Pharmacology and Children's Hospital Colorado, Aurora, CO, USA. Electronic address: Scott.Demarest@childrenscolorado.org.
¹¹ Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Perth, WA, Australia; Curtin School of Allied Health, Curtin University, Perth, WA, Australia. Electronic address: Jenny.Downs@telethonkids.org.au.

PMID: 38237219
DOI: 10.1016/j.eplepsyres.2024.107287

Abstract

Purpose: Validated measures capable of demonstrating meaningful interventional change in the CDKL5 deficiency disorder (CDD) are lacking. The study objective was to modify the Rett Syndrome Gross Motor Scale (RSGMS) and evaluate its psychometric properties for individuals with CDD.

Methods: Item and scoring categories of the RSGMS were modified. Caregivers registered with the International CDKL5 Clinical Research Network uploaded motor videos filmed at home to a protected server and completed a feedback questionnaire (n = 70). Rasch (n = 137), known groups (n = 109), and intra- and inter-rater reliability analyses (n = 50) were conducted.

Results: The age of individuals with CDD ranged from 1.5 to 34.1 years. The modified scale, Gross Motor-Complex Disability (GM-CD), comprised 17 items. There were no floor or ceiling effects and inter- and intra-rater reliability were good. Rasch analysis demonstrated that the items encompassed a large range of performance difficulty, although there was some item redundancy and some disordered categories. One item, Prone Head Position, was a poor fit. Caregiver-reported acceptability was positive. Scores differed by age and functional abilities.

Summary: GM-CD appears to be a suitable remotely administered measure and psychometrically sound for individuals with CDD. This study provides the foundation to propose the use of GM-CD in CDD clinical trials. Longitudinal evaluation is planned.

Keywords: CDKL5 deficiency disorder; Developmental epileptic encephalopathy; Gross motor function; Psychometric properties.

MeSH terms

Adolescent
Adult
Child
Child, Preschool
Epileptic Syndromes*
Humans
Infant
Motor Skills
Protein Serine-Threonine Kinases / genetics
Psychometrics
Reproducibility of Results
Rett Syndrome* / diagnosis
Rett Syndrome* / genetics
Spasms, Infantile*
Young Adult

Substances

CDKL5 protein, human
Protein Serine-Threonine Kinases

Supplementary concepts

CDKL5 deficiency disorder