Neurite Orientation Dispersion and Density Imaging for Assessing Acute Inflammation and Lesion Evolution in MS.

BACKGROUND AND PURPOSE: MR imaging is essential for MS diagnosis and management, yet it has limitations in assessing axonal damage and remyelination. Gadolinium-based contrast agents add value by pinpointing acute inflammation and blood-brain barrier leakage, but with drawbacks in safety and cost. Neurite orientation dispersion and density imaging (NODDI) assesses microstructural features of neurites contributing to diffusion imaging signals. This approach may resolve the components of MS pathology, overcoming conventional MR imaging limitations. MATERIALS AND METHODS: Twenty-one subjects with MS underwent serial enhanced MRIs (12.6 ± 9 months apart) including NODDI, whose key metrics are the neurite density and orientation dispersion index. Twenty-one age- and sex-matched healthy controls underwent unenhanced MR imaging with the same protocol. Fifty-eight gadolinium-enhancing and non-gadolinium-enhancing lesions were semiautomatically segmented at baseline and follow-up. Normal-appearing WM masks were generated by subtracting lesions and dirty-appearing WM from the whole WM. RESULTS: The orientation dispersion index was higher in gadolinium-enhancing compared with non-gadolinium-enhancing lesions; logistic regression indicated discrimination, with an area under the curve of 0.73. At follow-up, in the 58 previously enhancing lesions, we identified 2 subgroups based on the neurite density index change across time: Type 1 lesions showed increased neurite density values, whereas type 2 lesions showed decreased values. Type 1 lesions showed greater reduction in size with time compared with type 2 lesions. CONCLUSIONS: NODDI is a promising tool with the potential to detect acute MS inflammation. The observed heterogeneity among lesions may correspond to gradients in severity and clinical recovery after the acute phase.

Polygyny and women's health in rural Mali.

Women's social networks and social power are increasingly seen as important factors modulating their health in sub-Saharan Africa. Polygyny, a common marital structure in many societies, mediates important intra-household relationships by requiring both competition and co-operation among co-wives. Using mixed methods, semi-structured questionnaires were administered to 298 women aged 15-84 living in the Kolondiéba region of rural Mali in 1999, and supplemented by detailed interviews with 40 women. Three categories of outcome were explored: illness experience, therapeutic itinerary and social support received. Quantitative data were analysed using regression analysis and qualitative data using a grounded theory approach. In quantitative analyses, controlling for age and household wealth index, senior wives were less likely to be escorted to a healer by their husbands during illness than were junior wives or monogamous women. Polygynous women were also less likely to obtain a treatment for which there was a monetary fee. Fewer than one-third of polygynous women reported the assistance of a co-wife during illness in any given task. In qualitative analyses, women further related varied mechanisms through which polygyny impacted their health trajectories. These ranged from strongly supportive relationships, to jealousy because of unequal health or fertility, bias in emotional and material support provided by husbands, and accusations of wrong-doing and witchcraft. This study highlights the need for more prospective mixed methods analyses to further clarify the impact of polygyny on women's health-related experiences and behaviours in sub-Saharan Africa.

Metabolic and endocrine correlates of cognitive function in healthy young women.

OBJECTIVE: Obesity has been associated with cognitive decline in longitudinal studies of older individuals. We hypothesized that the cognitive sequelae of obesity may be detectable in the reproductive years. In addition, we explored the hypothesis that these associations may be mediated by the hormonal milieu. DESIGN AND METHODS: Of 49 young healthy lean and overweight women aged 20-45, we investigated the association between performance on a battery of cognitive tests, body composition parameters [body mass index, total fat, abdominal (visceral, subcutaneous, and total) adipose tissue, and muscle], and hormone levels (insulin, adiponectin, leptin, insulin-like growth factor 1 (IGF-1), estrogen, testosterone, and vitamin D). RESULTS: We found a significant negative association between both visceral adiposity and muscle, and performance in the domain of verbal learning and memory, after controlling for age and education. Other body composition parameters showed similar trends (0.05 < P < 0.10). Additionally, the degree of insulin resistance was negatively associated with executive function domain. None of the associations between the other hormones examined (adipokines, IGF-1, gonadal hormones, and vitamin D) and cognitive function were significant. CONCLUSION: These preliminary findings suggest a possible association between obesity and cognitive function in healthy young women of reproductive age. More research is warranted into the potential modulatory effect of insulin resistance on this association.