Little is known about the effect of obesity on brain structures and cognition in healthy older adults. This study examined the association between body mass index (BMI), regional volume differences in gray and white matter measured by magnetic resonance imaging (MRI), and cognitive functioning in older females. Participants included 95 community-dwelling older females (ages 52-92 years) who underwent extensive neuropsychological testing and high-resolution MRI scanning. Optimized voxel-based morphometry techniques were employed to determine the correlation between BMI and regional gray and white matter volumes. Volumes of significant regions were then correlated with cognitive functioning. Higher BMI was associated with decreased gray matter volumes in the left orbitofrontal, right inferior frontal, and right precentral gyri, a right posterior region including the parahippocampal, fusiform, and lingual gyri, and right cerebellar regions, as well as increased volumes of white matter in the frontal, temporal, and parietal lobes, even when hypertension was considered. Compared to normal weight women, obese women performed poorer on tests of executive functioning. Smaller gray matter volume in the left orbitofrontal region was associated with lower executive functioning. Additionally, despite the lack of significant group differences in memory and visuomotor speed, gray and white matter volumes predicted performance on these measures. The results provide additional evidence for a negative link between increased body fat and brain functioning in older females.

While an extensive literature is now available on age-related differences in white matter integrity measured by diffusion MRI, relatively little is known about the relationships between diffusion and cognitive functions in older adults. Even less is known about whether these relationships are influenced by the apolipoprotein (APOE) ε4 allele, despite growing evidence that ε4 increases cognitive impairment in older adults. The purpose of the present study was to examine these relationships in a group of community-dwelling cognitively normal older adults. Data were obtained from a sample of 126 individuals (ages 52-92) that included 32 ε4 heterozygotes, 6 ε4 homozygotes, and 88 non-carriers. Two measures of diffusion, the apparent diffusion coefficient (ADC) and fractional anisotropy (FA), were obtained from six brain regions -frontal white matter, lateral parietal white matter, the centrum semiovale, the genu and splenium of the corpus callosum, and the temporal stem white matter -and were used to predict composite scores of cognitive function in two domains, executive function and memory function. Results indicated that ADC and FA differed with increasing age in all six brain regions, and these differences were significantly greater for ε4 carriers compared to noncarriers. Importantly, after controlling for age, diffusion measures predicted cognitive function in a region-specific way that was also influenced by ε4 status. Regardless of APOE status, frontal ADC and FA independently predicted executive function scores for all participants, while temporal lobe ADC additionally predicted executive function for ε4 carriers, but not noncarriers. Memory scores were predicted by temporal lobe ADC but not frontal diffusion for all participants, and this relationship was significantly stronger in ε4 carriers compared to noncarriers. Taken together, age and temporal lobe ADC accounted for a striking 53% of the variance in memory scores within the ε4 carrier group.The results provide further evidence that APOE ε4 has a significant impact on the trajectory of age-related cognitive functioning in older adults. Possible mechanisms are discussed that could account for the associations between ε4, diffusion, and cognitive function, including the influence of ε4 on neural repair, oxidative stress, and the health of myelin-producing oligodendroglia.

ObjectiveTo assess whether the pattern of diffusion changes among a cohort of individuals showing BMI-related increases in white matter volume reflects healthy expansion of myelin or damaged white matter.Design and MethodsDiffusion MRI measures (axial, radial, and fractional anisotropy) were obtained from 94 females, ages 52–92. Relationships between BMI and diffusion measures were assessed controlling for age, hypertension, and diabetes status using general linear modelling. Associations between diffusion measures and cognitive status (memory, executive functions, and visuomotor speed) were assessed using multiple regressions, controlling for age, education, hypertension, and diabetes status.ResultsHigher levels of BMI were associated with lower axial diffusion in frontal, temporal, parietal, internal capsule, and cerebellar white matter. Lower fractional anisotropy was observed in bilateral temporal white matter and the right corticospinal tract, with high radial diffusion in temporal and temporoparietal white matter. Importantly, diffusion measures predicted reductions in executive functioning, memory, and visuomotor speed.ConclusionsThe pattern of diffusion changes in regions of white matter showing BMI-related volume increases are not due to expansion of normal myelin, but instead suggest damage to white matter that has important consequences for cognitive functioning.

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Summary Objective To examine the long‐term outcome of psychological status, personality, and health‐related quality of life (HRQoL) in patients with psychogenic nonepileptic seizures (PNES) and to define predictors of favorable outcome of cessation of PNES. Method Patients diagnosed with PNES during video–electroencephalography (EEG) monitoring at the Erlangen Epilepsy Center were contacted 1‐16 years after communicating the diagnosis. Follow‐up information from each participant was obtained by interview (PNES outcome) and by self‐reported questionnaires of psychological symptoms (Beck Depression Inventory‐II, Symptom Checklist‐90‐Standard, Dissociative Symptoms questionnaire), personality traits (Freiburg Personality Inventory‐Revised), and HRQoL (36‐Item Short Form Health Survey). Results Fifty‐two patients participated in the study (mean age ± standard deviation [SD] 40.5 ± 14.0 years; 75% female, follow‐up: 5.3 ± 4.2 years). Nineteen patients (37%) were free of PNES for the past 12 months. Patients with persisting PNES were older at disease onset (32.9 vs 22.3 years, P < 0.01) and diagnosis (40.5 vs 27.2 years, P < 0.001), and showed worse psychological functioning, lower extraversion and life satisfaction, and higher inhibitedness and worse HRQoL than PNES‐free patients. Patients with cessation of PNES were within the normal range in all dimensions. Cessation of PNES was best predicted by younger age at PNES onset and higher extraversion. Significance Outcome of PNES is poor, psychopathology is high, and HRQoL is low in patients with persistent PNES but may normalize with PNES cessation. High introversion and older age at PNES onset are risk factors for persistent PNES.