Structural-functional brain network coupling predicts human cognitive ability.

Individual differences in general cognitive ability (GCA) have a biological basis within the structure and function of the human brain. Network neuroscience investigations revealed neural correlates of GCA in structural as well as in functional brain networks. However, whether the relationship between structural and functional networks, the structural-functional brain network coupling (SC-FC coupling), is related to individual differences in GCA remains an open question. We used data from 1030 adults of the Human Connectome Project, derived structural connectivity from diffusion weighted imaging, functional connectivity from resting-state fMRI, and assessed GCA as a latent g-factor from 12 cognitive tasks. Two similarity measures and six communication measures were used to model possible functional interactions arising from structural brain networks. SC-FC coupling was estimated as the degree to which these measures align with the actual functional connectivity, providing insights into different neural communication strategies. At the whole-brain level, higher GCA was associated with higher SC-FC coupling, but only when considering path transitivity as neural communication strategy. Taking region-specific variations in the SC-FC coupling strategy into account and differentiating between positive and negative associations with GCA, allows for prediction of individual cognitive ability scores in a cross-validated prediction framework (correlation between predicted and observed scores: r = 0.25, p < .001). The same model also predicts GCA scores in a completely independent sample (N = 567, r = 0.19, p < .001). Our results propose structural-functional brain network coupling as a neurobiological correlate of GCA and suggest brain region-specific coupling strategies as neural basis of efficient information processing predictive of cognitive ability.

Neuromorphometric associations with mood, cognition, and self-reported exercise levels in epilepsy and healthy individuals.

Regular physical activity may promote beneficial neuroplasticity, e.g., increased hippocampus volume. However, it is unclear whether self-reported physical exercise in leisure (PEL) levels are associated with the brain structure features demonstrated by exercise interventions. This pilot study investigated the relationship between PEL, mood, cognition, and neuromorphometry in patients with idiopathic generalized epilepsy (IGEs) compared to healthy controls (HCs). Seventeen IGEs and 19 age- and sex-matched HCs underwent magnetic resonance imaging (MRI) at 3T. The Baecke Questionnaire of Habitual Physical Activity, Profile of Mood States, and Montreal Cognitive Assessment (MoCA) assessed PEL, mood, and cognition, respectively. Structural MRI data were analyzed by voxel- and surface-based morphometry. IGEs had significantly lower PEL (p < 0.001), poorer mood (p = 0.029), and lower MoCA scores (p = 0.027) than HCs. These group differences were associated with reduced volume, decreased gyrification, and altered surface topology (IGEs < HCs) in frontal, temporal and cerebellar regions involved in executive function, memory retrieval, and emotional regulation, respectively. These preliminary results support the notion that increased PEL may promote neuroplasticity in IGEs, thus emphasizing the role of physical activity in promoting brain health in people with epilepsy.

Do people with epilepsy want to participate in an exercise intervention randomized controlled trial? - Results of a brief survey and its preliminary application.

Our goal was to survey people with epilepsy (PWE) about their interest in and factors that may influence willingness and ability to participate in an exercise randomized controlled trial (RCT). A brief survey was administered to 100 PWE asking if they would take part in a hypothetical 6-week exercise intervention RCT. Follow-up questions queried reasons for and against participation and why participation would be difficult. Sixty-nine percent of respondents indicated willingness to participate. The top reason for participation was "to improve overall health with exercise" (n = 49). The top reason for why participation would be difficult was they "do not have a reliable source of transportation" (n = 27). The top reason for not participating was "not interested in research participation" (n = 19). Preliminary results were used to budget for transportation in a prospective RCT (NCT04959019). Of the first 27 PWE enrolled (63 % female; 44 % African American/Black), six (50 % female; 50 % African American/Black) have used the transportation service. The majority of PWE surveyed were interested in participating in an exercise RCT, but some indicated barriers. Accommodating transportation in an ongoing RCT has facilitated recruitment of PWE who would otherwise not be able to participate. Barriers to participation should be accounted for when designing studies.

Relationships between cognitive function, seizure control, and self-reported leisure-time exercise in epilepsy.

Exercise may be a strategy for improvement of cognitive deficits commonly present in people with idiopathic generalized epilepsies (IGE). We investigated the relationship between cognition and level of physical exercise in leisure (PEL) in people with IGE who have been seizurefree for at least 6 months (IGE-) as compared to those who have not been seizurefree (IGE+) and healthy controls (HCs). We hypothesized that higher level of physical exercise is associated with better cognitive functioning in patients with IGE and HCs, and that seizure control affects both PEL levels and cognitive functioning in patients with IGE. We recruited 75 participants aged 18-65: 31 people with IGE (17 IGE-, 14 IGE+) and 44 HCs. Participants completed assessments of quality of life (SF-36), physical activity levels (Baecke questionnaire and International Physical Activity Questionnaire (IPAQ)) and cognition (Montreal Cognitive Assessment (MoCA), Hopkins Verbal Learning Test - Revised (HVLT), and flanker task). Group differences (HCs vs. IGE; HCs vs. IGE+ vs. IGE-) were assessed. Pearson correlations examined linear relationships between PEL and cognitive performance. Groups were similar in age and sex. Compared to HCs, patients with IGE had higher body mass index, fewer years of education, and consistently scored worse on all measures except flanker task accuracy on incongruent trials. When examining IGE- and IGE+ subgroups, compared to HCs, both had higher body mass index, and fewer years of education. Healthy controls scored significantly better than one or both of the IGE groups on SF-36 scores, PEL levels, IPAQ activity level, MoCA scores, HVLT learning and long-delay free-recall scores, and flanker task accuracy on congruent trials. Among patients with IGE, there were no significant differences between age of epilepsy onset, duration of epilepsy, number of anti-seizure drugs (ASDs) currently being used, or the group distribution of type of IGE. In the combined sample (IGE+, IGE- and HCs), PEL positively correlated with MoCA scores (Pearson's r = 0.238; p = 0.0397) and with flanker task accuracy on congruent trials (Pearson's r = 0.295; p = 0.0132). Overall, patients with IGE performed worse than HCs on cognitive and physical activity measures, but the cognitive impairments were more pronounced for IGE+, while physical exercise levels were less for patients with IGE regardless of seizure control. While positive relationships between leisure-time PEL and cognitive performance are promising, further investigations into how exercise levels interact with cognitive functioning in epilepsy are needed.