Validation of the Edinburgh Cognitive and Behavioural Amyotrophic Lateral Sclerosis Screen (ECAS): A cognitive tool for motor disorders

Abstract

Our objective was to assess the validity of the Edinburgh Cognitive and Behaviour ALS Screen (ECAS), a multi-domain screen designed to detect cognitive deficits in patients with motor disorders. Forty ALS patients (without pre-diagnosed dementia) and 40, age-, gender- and education-matched healthy controls were recruited. All participants underwent extensive neuropsychological assessment and the ECAS. Performance at neuropsychological assessment across five domains (fluency, executive function, language, memory and visuospatial function) was compared to the ECAS ALS-Specific (fluency, executive functions and social cognition, language), ALS Non-specific (memory, visuospatial functions), and Total scores. Data from the healthy controls produced population-based abnormality cut-offs: composite score performance ≤ 2 SD in any domain classified impairment at neuropsychological assessment. Thirty-three percent of patients were impaired, most commonly in a single domain (executive or language dysfunction). Receiver Operator Curve (ROC) analyses using ECAS Total scores and ALS-Specific scores revealed 85% sensitivity and 85% specificity in the detection of cognitive impairment characteristic of ALS (fluency, executive function, language). A five-point borderline range produced optimal values (ALS-Specific Score 77–82, and ECAS-Total Score 105–110). In conclusion, validation against gold standard extensive neuropsychology demonstrated that the ECAS is a screening tool with high sensitivity and specificity to impairment characteristic of ALS.

Key words::

• Cognition
• screen
• executive functions
• language
• fluency

Acknowledgements

This study was funded by an award from the Motor Neurone Disease Association. The authors thank all the people with MND and their carers for participating in this research. They would also like to pay special thanks to Gill Stott, Richard Davenport, Suvankar Pal, George Gorrie, Myles Connor, David Simpson, Martin Zeidler, Uve Spelmeyer and all the regional clinical MND specialist teams for their help with recruitment of patients. We thank the MND Register, hosted by Euan MacDonald Centre for MND Research and funded by MND Scotland.

Declaration of interest: The authors have no known conflict of interest in relation to the publication of this paper. JN, JF and EN were funded by an award from the Motor Neurone Disease Association when undertaking this research. The authors alone are responsible for the content and writing of the paper.