Describing and assessing behavioural symptoms in amyotrophic lateral sclerosis with and without frontotemporal dementia: a scoping review.

Purpose of review: Alongside motor and cognitive symptoms, amyotrophic lateral sclerosis (ALS) and ALS with frontotemporal dementia (ALSFTD) present with behavioural symptoms, which can be challenging for all affected by the disease. A scoping review of studies published between 2011 and 2024 was conducted to present the breadth of behavioural symptoms in ALS and ALSFTD, explore how they are described and assessed, and identify patterns in the literature.

Findings: This scoping review identified 3939 articles, with 111/3939 meeting eligibility criteria. Most studies were from Australia (23.22%), Italy (16.94%) and the UK (14.29%); 75.67% were cross-sectional. Sample size ranged from 1 to 1013, as case studies were included. Overall mean age (100/111 studies) was 61.32 (SD = 4.15). Proportion of male patients (reported 102/111 studies) was 61.49%; mean disease duration (reported in 86/111 records) was 32.63 months (SD = 24.72). Papers described a broad range of behavioural symptoms (465 examples), which were thematically collated into seven categories: disinhibition (27.74%), apathy (25.16%), perseverative/compulsive behaviours (17.42%), hyperorality (10.53%), loss of sympathy or empathy (8.6%), psychotic symptoms (7.74%), and loss of insight about disease and changes (2.8%). Most studies (78.37%) used validated behavioural assessments that elicited carer's perspectives.

Summary: Despite extensive evidence of behavioural symptoms in ALS, implementation of assessments and management of behavioural symptoms in clinical care remain limited. Clinicians must assess behavioural symptoms, as these can negatively affect disease prognosis, patient treatment engagement and increase family distress. Measures capturing carers' perspectives through interviews are ideal as they can reveal anosognosia, lack of sympathy and lack of empathy.