Frontal lobe dysfunction in amyotrophic lateral sclerosis.
The aim of the present study was to investigate the involvement of frontal lobe dysfunction in amyotrophic lateral sclerosis (ALS) using ocular motor paradigms and neuropsychological testing. Fifty-one patients with ALS participated in the following ocular motor tasks: (1) a three-choice task and (2) a remembered saccade task. The patients underwent a clinical and neuropsychological evaluation. One-third of ALS patients presented with signs of frontal dysfunction, as determined by their high distractibility factors (DF) in the three-choice task and their performances in both the Wisconsin and Stroop tests. ALS patients exhibited longer latencies to eye movement than controls in the performance of the remembered saccade task, specifically in performance of both remembered and delayed saccades, but saccade accuracy was not impaired. Finally, performance indices of the ocular motor tasks, in particular the DF, was correlated only with the degree of dysarthria.