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Introduction : Amyotrophic lateral sclerosis (ALS) has heterogeneous manifestations ranging from motor neuron degeneration to cognitive and behavioral impairment. This study aims to clarify the interactions between cognition and behavioral symptoms with relevant disease predictors and with cognitive reserve (CR), quantified through education, physical activity, and occupation proxies. Methods : A prospective sample of 162 ALS patients and 61 controls were evaluated with the Edinburgh Cognitive and Behavioral ALS Screen (ECAS) (dependent variable), a Cognitive Reserve Index questionnaire (CRIq) and demographic data (age and sex), and, for patients, clinical variables: disease duration, site of onset, the ALS Functional Rating Scale (ALSFRS), forced vital capacity (FVC), and gene mutation chromosome 9 open reading frame 72 ( C9orf72 ) (independent variables). Multiple regression and mediation analyses were performed to predict cognitive and behavioral symptoms. Results : For the ALS group, the statistical model explained 38.8% of variance in ECAS total ( p  < 0.001), 59.4% of executive functions ( p  < 0.001), and 55% of behavioral symptoms ( p  < 0.001). For controls, it accounted for 52.8% of variance in ECAS total ( p  < 0.001). Interaction effects and mediation analysis showed CR is an ECAS total modulator, with a differential effect within groups ( p  < 0.001). Verbal fluency was the single best cognitive score to differentiate patients from controls ( p  = 0.004), and the gene mutation C9orf72 was found to be a behavioral symptom' predictor in patients ( p  = 0.009). Conclusion : This study supports the proposed concept that CR acts as a cognitive modulator in ALS patients and healthy individuals. Moreover, CR also modulates behavioral manifestations in ALS.

This study aims to investigate if education (as a cognitive reserve proxy) modifies the profile of cognitive performance. We hypothesize that participants with higher education can remain functional (due to a better executive performance), despite a more severe memory impairment, compared with lower education individuals. One hundred and sixty-six mild cognitive impairment (MCI) individuals with at least one comprehensive neuropsychological evaluation were included in a retrospective, cross-sectional study and divided into two groups (Low Education-LE [1-4 years] and Medium-to-High Education-MHE [> 4 years]). A total of 22 neuropsychological measures were analyzed. Age-adjusted results were subject to simple regression analyses to determine the variance explained by education. Average scores and proportions of low performances were subject to group comparison. The results showed similar cognitive decline patterns between individuals with LE and MHE, with no significant difference in each cognitive domain. However, MHE revealed a steeper decline in certain cognitive domains, such as sustained attention and episodic memory, compared with the LE. Moreover, MHE showed a trend to higher proportion of tests affected when compared to LE. These suggest that individuals with higher education may remain in a MCI stage despite a more widespread cognitive impairment, reflecting a higher cognitive reserve.

We aimed to identify the early predictors of cognitive decline, and primary care physicians' (PCP) ability to diagnose cognitively impaired subjects, in a cohort of individuals recruited in primary care centers. Independent adults, aged ≥50 years at inception, with an overall low level of education, undertook a prospective clinical and cognitive evaluation targeting memory, attention and executive functions. At follow-up subjects were classified as cognitively normal (CN) or impaired (CI). Of 275 subjects (70.4 ± 8.3 years old, 176 females, 7.5 ± 4.4 education, 162 with MRI), 31 (11.2%) presented CI 4.9 years later, the majority (64.5%) presenting subjective cognitive complaints. PCP could correctly identify 40% of CI individuals, particularly if they presented current cognitive complaints. Male sex (OR = 3.117; CI95%: 1.007-9.645), age (OR = 1.063; CI95%: 1.004-1.126) and baseline scores on TMT-B (OR = 0.225; CI95%: 0.073-0.688) and Vocabulary (OR =  0.940; 95% CI: 0.894-0.986) predicted CI. This study shows that measures indicating poor cognitive reserve and low executive performance (as shown by low vocabulary and executive test scores, respectively) can be early indicators of the risk of decline, stressing the role of cognitive assessment as part of prevention/early intervention programs. The results also underline the need to help PCP to improve the detection of subjects with cognitive decline.