Can Executive Cognitive Measures Differentiate Between Patients with Spinal- and Bulbar-Onset Amyotrophic Lateral Sclerosis?

Although executive functions in sporadic non-demented amyotrophic lateral sclerosis (ALS) patients are mostly affected, it remains unclear whether executive measures can differentiate between patients with bulbar and spinal ALS forms. Thirty spinal and 18 bulbar-onset ALS patients (ALS-s and ALS-b, respectively) as well as 47 demographically related healthy controls were examined in executive processes (Trail Making Test-part B [TMT-(B-A)]; Stroop Neuropsychological Screening Test [SNST]; Similarities subtest of the Wechsler Adult Intelligence Scale [WAIS Similarities]; Wisconsin Card Sorting Test [WCST]). ALS subgroups were similar with regard to demographic characteristics and disease duration; yet, ALS-b showed greater disease severity compared with ALS-s patients (p .006). Both ALS-s and ALS-b patients were significantly inferior to healthy controls on TMT-(B-A) (p .001), SNST (p .009 and p .02, respectively) and WAIS Similarities (p .031 and p .021, respectively), whereas ALS-s performed significantly worse than controls on the WCST perseverative responses (p .005). However, neuropsychological measures did not significantly differ between ALS subgroups (p .05). Despite the fact that ALS-b patients may present greater disease severity, specific executive impairments that are present early in the course of ALS seems to be independent of the site of onset.