Despite evidence--‐based literature and society guidelines regarding appropriateness of MR imaging in the setting of low back pain, there continues to be a high utilization of MR scans of the lumbar spine in the emergency department setting. An IRB--‐ approved 2 year retrospective review was performed of the imaging and electronic health record at a regional academic medical center encompassing 2 EDs to compare demographic, exam and “soft” factors that may explain pressure or expectation for MR imaging in the ED setting. Our goal is to create a novel model to identify the qualitative factors that effect physician imaging ordering behavior in the ED and extrapolate them into quantifiable data points that can be objectively compared. The results of this project will help us better understand the nuances of the physician--‐patient relationship in the ED and allow us to build imaging protocols that reflect the complexity of care provided in the emergency department setting.

The early stage cognitive deficits in Alzheimer's disease (AD) have been attributed to soluble, oligomeric forms of Amyloid [Beta] (sA[Beta]) and its effect on synaptic structure, function glutamate receptor content. Excitatory synapses in the brain mainly reside on dendritic spines. Their synaptic activity involves ionic currents that are mediated by glutamate receptors. Dendritic spines are rich in the cytoskeletal component actin, which mediates spine stability and morphology as well as anchors receptors to the spine surface. We observe that sA[Beta} reduces the expression of total and surface glutamate receptors through a mechanism that involves an increase in the activity of cofilin, an actin severing protein. In addition, we show that inhibition of cofilin's F-actin severing activity prevents the decrease in surface glutamate receptor expression witnessed in the presence of sA[Beta]. This provides a novel mechanism behind sA[Beta]- induced synaptic dysfunction in Alzheimer's Disease

Objective

Vascular risk factors like hyperlipidemia may adversely affect brain function. We hypothesized that increased serum triglycerides are associated with decreased executive function and memory in nondemented elderly subjects. We also researched possible vascular mediators and white matter microstructure as assessed with diffusion tensor imaging (DTI).

Design/method

Participants were 251 nondemented elderly adults (54% male) with a mean age of 78 (SD = 6.4; range: 62-94) years and a mean education of 15.6 (SD = 2.9; range: 8-23) years. Fasting blood samples were used to detect serum triglyceride and low-density lipoprotein (LDL) levels along with ApoE4 status. DTI was used to determine whole brain fractional anisotropy (FA). Composite executive and memory scores were derived from item response theory. Clinical Dementia Rating (CDR) scores provided informant-based measures of daily functioning.

Results

Triglyceride levels were inversely correlated with executive function, but there was no relationship with memory. Controlling for age, gender, and education did not affect this correlation. This relationship persisted after controlling for vascular risk factors like LDL, total cholesterol, CDR and ApoE4 status. Lastly, adding whole-brain FA to the model did not affect the correlation between triglycerides and executive function.

Conclusion

Triglyceride levels are inversely correlated with executive function in nondemented elderly adults after controlling for age, education, gender, total cholesterol, LDL, ApoE4 status, CDR, and white-matter microstructure. The fact that the effect of triglycerides on cognition was not clearly mediated by vascular risks or cerebrovascular injury raises questions about widely held assumptions of how triglycerides might impact cognition function. (PsycINFO Database Record