The Edinburgh Cognitive and Behavioral ALS screen: relationship to age, education, IQ and the Addenbrooke's Cognitive Examination-III

The Edinburgh Cognitive and Behavioral ALS Screen (ECAS) was developed to assess cognitive and behavioral changes common in Amyotrophic Lateral Sclerosis and other diseases affecting motor functions. It focuses on domains typically affected by the frontotemporal syndrome (executive and language functions, fluency and behavior), but assesses also memory and visuospatial functions. Objectives: (A) To investigate the relationship between the ECAS and the Addenbrooke's Cognitive Examination (ACE-III). (B) To investigate the effects of age, education, and IQ on the ECAS and create appropriate cutoff scores to determine abnormality. Methods: (A) 57 healthy participants (aged 35-80) were assessed with the ECAS, the Wechsler Abbreviated Scale of Intelligence (WASI-II), and the ACE-III. (B) 80 healthy participants (aged 51-80) were divided into four groups according to age and education; and were tested with the ECAS and the WASI-II. Results: The ECAS and the ACE-III have a good convergent validity with a significant correlation. Regression analysis revealed that IQ, followed by age, were the strongest predictors of the total ECAS score. IQ predicted 24% of the ECAS and 46% of the ACE-III variance. Education was not a significant predictor over and above IQ for both the ECAS and the ACE-III. Abnormality cutoff scores adjusted for age and education are presented. Conclusions: The ECAS shows good convergent validity with the ACE-III, but is less influenced by intelligence and presents less ceiling effects. The inclusion of an executive function assessment and behavioral interview in the ECAS makes it particularly useful for the assessment of frontal lobe disorders.