Cognitive and behavioral status in Japanese ALS patients: a multicenter study

Amyotrophic lateral sclerosis (ALS) patients may present with cognitive and behavioral abnormalities similar to frontotemporal dementia (FTD). In this multicenter study we examined Japanese ALS patients with and without FTD in order to characterize the full extent of cognitive and behavioral abnormalities, including associations with functional motor status, anxiety and depression.

Patients were evaluated using the Montreal Cognitive Assessment (MoCA), Frontal Assessment Battery (FAB), Hospital Anxiety and Depression Scale, ALS Functional Rating Scale-Revised, spirometry, and verbal fluency tests. Caregivers were asked to complete the ALS-FTD-Questionnaire (ALS-FTD-Q), a behavioral screen. We defined severe cognitive impairment (MoCA < 21 or FAB < 11), mild impairment (11 ≤ MoCA ≤ 25 or 11 ≤ FAB ≤ 15), and normal cognition (MoCA > 25 or FAB > 15). Severe and mild behavioral impairments and normal behavior were defined by the ALS-FTD-Q scores.

In 145 ALS patients, better cognitive scores were correlated with earlier age at onset, whereas a worse behavioral score was associated with a longer disease duration and higher level of anxiety and depression. Around seventy percent of all ALS patients showed mild (40-45%) or severe cognitive impairment with cognitive impairment outnumbering behavioral impairment fivefold. Cognitive functions were more impaired in patients with age of onset over 65 years, while behavioral scores were not related to age.

Considering the high prevalence of in particular cognitive impairment, and the diversity of impairments, the cognitive and behavioral aspects of Japanese ALS patients should be given more attention clinically.