Kassardjian and colleagues describe the clinical, serologic, and electrophysiologic characteristics of necrotizing autoimmune myopathy (NAM), compare patient subgroups, and determine clinical outcome predictors. Clinical, electrophysiologic, and pathologic characteristics were collected and compared among patient subgroups, and predictors of response to treatment were identified by univariate logistic regression. They report that NAM was idiopathic in half of this cohort with clinical and histopathologically defined disease and that, in the remainder, NAM was associated with statin medication, cancer, or connective tissue disease. Editorial perspective in support of these data is provided by Matthew N. Meriggioli, MD.
Harrison and colleagues evaluate the clinical relevance of measures of cortical lesion (CL) burden derived from high-field magnetic resonance imaging (MRI) in multiple sclerosis (MS). Lesions were classified as leukocortical, intracortical, or subpial. Images were segmented using the Lesion-TOADS (Topology-Preserving Anatomical Segmentation) algorithm, and brain structure volumes and white matter lesion volume were reported. This study provides in vivo evidence that CLs are associated with cognitive and physical disability in MS and that leukocortical and subpial lesion subtypes have differing clinical relevance. Quantitative assessments of CL burden on high-field MRI may further our understanding of the development of disability and progression in MS and lead to more effective treatments. Editorial perspective in support of these data is provided by Robert T. Naismith, MD.
Willette and coauthors determine whether insulin resistance predicts Alzheimer disease–like global and regional glucose metabolism deficits in late middle–aged participants at risk for Alzheimer disease and examine whether insulin resistance–predicted variation in regional glucose metabolism is associated with worse cognitive performance. Participants underwent cognitive testing, fasting blood draw, and fludeoxyglucose F 18–labeled positron emission tomography at baseline. Their results show that insulin resistance, a prevalent and increasingly common condition in developed countries, is associated with significantly lower regional cerebral glucose metabolism, which in turn may predict worse memory performance.
Gregg et al evaluate the association of incidental cerebral microbleeds (CMBs) with resting-state cerebral blood flow (CBF), cerebral metabolism, cerebrovascular disease, β-amyloid, and cognition. Three-Tesla magnetic resonance imaging was performed with susceptibility-weighted imaging or gradient-recalled echo to assess CMBs, arterial spin labeling for CBF, and T1- and T2-weighted imaging for atrophy, white matter hyperintensities, and infarcts. They find that, in cognitively normal elderly individuals, incidental CMBs in cortical locations are associated with widespread reductions in resting-state CBF, which indicates that chronic hypoperfusion may put these people at risk for neuronal injury and neurodegeneration.
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