Longitudinal assessment of the Edinburgh Cognitive and Behavioural Amyotrophic Lateral Sclerosis Screen (ECAS): lack of practice effect in ALS patients?

OBJECTIVE

The study objective was to assess whether controls and ALS patients show a practice effect in the Edinburgh Cognitive and Behavioural ALS Screen (ECAS) on repeated longitudinal testing and if the ECAS detects progression of cognitive or behavioural changes over time.

METHODS

The ECAS was administered serially to ALS patients (n = 24 after six months, n = 10 after 12-18 months) and controls (n = 21 after six months). The ECAS was fully performed by all participants. For comparison purposes the Frontal Assessment Battery (FAB) was administered to a subgroup of 14 patients and 14 controls.

RESULTS

After six months controls showed a significantly higher overall score (p < 0.001) and significantly higher scores in all subdomains of the ECAS, except for visuospatial function and fluency. ALS patients showed no significant difference in any score of the ECAS after six months and up to18 months. Behavioural changes were increasingly, but not statistically, significant, noted by patient carers. The FAB was no longer applicable due to progressive motor deficits in 20% of ALS patients.

CONCLUSIONS

In conclusion, in contrast to healthy controls, ALS patients show no practice effects. This could reflect 'pre-symptomatic' cognitive decline and progressive behavioural symptoms.