Frontal lobe-mediated behavioral changes in amyotrophic lateral sclerosis: Are they independent of physical disabilities?

Abstract

Objective Several studies have indicated that frontal cognitive impairment is present in patients with amyotrophic lateral sclerosis (ALS). However, it remains to be elucidated whether the behavioral change is a direct consequence of ALS pathology or the measurements are confounded by the physical impairments. We examined frontal lobe-mediated behavioral dysfunction in daily living in patients with ALS by using the family- and self-rating forms of the Frontal Systems Behavior Scale (FrSBe) and assessed the relationship between the scores and motor impairments or ventilatory status. Methods We examined 24 patients with sporadic ALS, who were aged 65.7 ± 10.5 years with mean disease duration of 2.3 ± 1.7 years, Mini-Mental State Examination score of ≥ 24, normal Self-rating Depression Scale, no need of assistance in daily life, normal respiratory function, and normal arterial blood gas analytes. We examined the relationship between FrSBe scores and ALS Functional Rating Scale (ALSFRS), respiratory function, and arterial blood gas analytes. Results The scores of family- and self-rating FrSBe were significantly higher after onset of ALS than before onset, most notably in apathy. The family-rating FrSBe scores after onset were not correlated with ALSFRS, respiratory function, or arterial blood gas analytes. Conclusion The frontal-lobe-related behavioral dysfunction is present after the onset of ALS, but is independent of physical impairments.