Background: Although cognitive and social-emotional deficits have not been considered as typical clinical feature of with amyotrophic lateral sclerosis (ALS), increased understanding of association of frontotemporal dementia (FTD) with pathogenic mutation and wide spreading of ALS lead us analyse the importance of neuropsychological manifestation in ALS. Recent researches have suggested that neuropsychological impairments commonly present in ALS patients and may play an important role in clinical decision-making and the caregiver’s burden. The aim of current study was to investigate cognitive impairment, especially on focused on patterns of emotional perception based on the recognition of facial expressions in Korean ALS patients.

Methods: Twenty-four ALS patients were recruited consecutively from the Motor Neuron Disease (MND) Clinic at Hanyang University Hospital between November 2013 and April 2014. Clinical measures included demographic data, ALS Functional Rating Scale-Revised (ALSFRS-R) score, and disease progression rate. Twenty-four patients with ALS and 24 age- and sex-matched healthy controls completed neuropsychological tests and facial emotion recognition tasks (the ChaeLee Korean Facial Expressions of Emotions [ChaeLee-E test]). The ChaeLee-E test includes facial expressions for seven emotions (happiness, sadness, anger, disgust, fear, surprise, and neutral).

Results: ALS patients and healthy controls subjects did not differ in age, gender, or level of education, but K-MMSE and FAB scores for ALS patients were significantly lower than for controls (K-MMSE, 26.9±2.7 vs 28.8±1.2, p=0.003; FAB, 13.0±4.0 vs 16.0±3.7, p=0.010). Ten ALS patients (41.7%, 10 of 24) were cognitively and behaviorally intact, and the others were impaired. Among the neuropsychological dysfunction in ALS patients, three patients (12.5%, 3 of 24) had frontotemporal dementia (FTD). The ability to perceive facial emotions was significantly worse among ALS patients than among control subjects (65.2±18.0% vs 77.1±6.6% [mean±SD], p = 0.009). Eight of the 24 patients (33%) scored below the 5th percentile score of controls for recognizing facial emotions.

Conclusions: These findings expand the spectrum of restrictive cognitive dysfunction into diverse comprehensive neuropsychological dysfunction, and screening for these emotional perception deficits may help clinicians to understand the overlapping spectrum between ALS and multisystem disorders including FTD. Furthermore, the perceptional impairments for specific individual emotions and related neural substrates should be evaluated, and future researches are needed to determine the serial changes in emotion in the patients with population and optimal clinical management for cognitive impairments or emotional deficits.