Frontal assessment battery and frontal atrophy in amyotrophic lateral sclerosis

Objectives: To determine the potential utility of the frontal assessment battery (FAB)in assessing cognitive impairments in amyotrophic lateral sclerosis (ALS), we investigatedthe association between the FAB score and regional gray matter volume, andascertained whether the regional brain alterations related to cognitive impairmentsoccur in relatively mild stage of ALS.Materials and Methods: Twenty-fourALS patients with a Mini-MentalStateExamination score of >23, a normal score on the Self-RatingDepression Scale, little orno disturbance in speech and handling utensils on the ALS Functional Rating Scale(ALSFRS), and normal measures on respiratory tests (respiratory function test and arterialblood gas analysis), and two age-matchednormal control groups (one for FABassessment and the other for brain morphometry) underwent FAB testing and structuralmagnetic resonance imaging. We applied voxel-basedmorphometry to investigatethe relationship between the FAB score and regional brain alteration, andassessed the relationship between the altered regional brain volume and ALSFRS orrespiratory tests.Results: Frontal assessment battery scores were significantly lower in ALS patientsthan in normal controls. Volume reduction in the right orbitofrontal gyrus in ALS wascorrelated with a lower FAB score. There was no correlation between the right orbitofrontalgyrus volume and ALSFRS or respiratory tests.Conclusions: The results suggest that the FAB is an adequate tool for detecting cognitiveimpairments related to frontal lobe pathology in the relatively mild stage of ALS,independent of physical dysfunctions