Does executive functioning contribute to locomotion in amyotrophic lateral sclerosis patients?

OBJECTIVE

Amyotrophic lateral sclerosis (ALS) is associated with co-existing motor and cognitive impairment in almost half of the patients; however, the relationship between cognitive and motor functioning has rarely been studied in ALS. We hypothesized that impaired executive functioning would be linked to poor mobility in ALS patients.

METHODS

A total of 49 non-demented ambulant ALS patients (mean age: 68.4 ± 12.6 years; 53% female), were evaluated in the Centre for ALS and Related Disorders of Geneva University Hospitals. We assessed executive function and locomotion using bedside tests: the Frontal Assessment Battery (FAB), the Timed Up and Go (TUG) and its imagined version (iTUG).

RESULTS

The mean (SD) FAB was 16.4 (1.9), mean TUG was 15.7 (13.9) s, and the mean iTUG was 8.9 (7.6) s. No correlation was found between the FAB, TUG, and iTUG. There was also no correlation between the total FAB score and its 6 subtests with global disability assessed by the ALSFRS-R score.

CONCLUSIONS

No correlation between executive function and locomotion was found in a group of non-demented ambulant ALS patients, as measured by screening tools of cognitive function. This absence of correlation suggests that locomotion is mainly affected by other factors than cognition, such as muscle strength or pyramidal symptoms.