Authors: Tholen, Susanne | Schmaderer, Christoph | Chmielewski, Stefan | Förstl, Hans | Heemann, Uwe | Baumann, Marcus | Steubl, Dominik | Grimmer, Timo
Article Type: Research Article
Abstract: Background: Cognitive impairment in hemodialysis patients is common, but the underlying pathogenesis remains unclear. Alzheimer’s disease is the most common cause of dementia in the general elderly population. Histopathological hallmarks are, among others, senile plaques, which consist of amyloid-β (Aβ). Objective: To measure plasma levels of Aβ42 and Aβ40 during hemodialysis and to examine potential associations with cognitive performance in cognitively impaired hemodialysis patients. Methods: Plasma samples of 26 hemodialysis patients were collected shortly before, after 50% of dialysis time, and at the end of a dialysis session. Aβ42 and Aβ40 levels were measured by a high-sensitivity ELISA for human …amyloid-β. Cognition was tested under standardized conditions using the Montreal Cognitive Assessment (MoCA) as proposed previously. Results: Clearance rates of both peptides during one dialysis session were 22% and 35% for Aβ42 and Aβ40 , respectively. Aβ42 but not Aβ40 baseline levels were significantly associated with MoCA test results (r = 0.654, p = 0.001). Conclusion: In cognitively impaired hemodialysis patients plasma Aβ42 levels were associated with cognitive performance and both Aβ42 and Aβ40 plasma levels could be effectively reduced by dialysis. By inducing peripheral Aβ sink, hemodialysis may be considered as an anti-amyloid treatment strategy. Show more
Keywords: Alzheimer’s disease, amyloid-beta, cognitive impairment, hemodialysis
DOI: 10.3233/JAD-150662
Citation: Journal of Alzheimer's Disease, vol. 50, no. 3, pp. 791-796, 2016
Authors: Neumann, Jan | Schmaderer, Christoph | Finsterer, Sebastian | Zimmermann, Alexander | Steubl, Dominik | Helfen, Anne | Berninger, Markus | Lohöfer, Fabian | Rummeny, Ernst J. | Meier, Reinhard | Wildgruber, Moritz
Article Type: Research Article
Abstract: BACKGROUND: Quantitative Imaging of microcirculatory disorders is challenging. OBJECTIVE: To investigate the feasibility of 2D Fluorescence Optical Imaging (FOI) for characterization and quantification of microcirculatory disorders in peripheral arterial occlusive disease (PAOD) of the upper extremity. METHODS: 9 patients with various clinical presentations of PAOD of the upper extremity were included. Quantitative analysis of both hands was performed by assessing the fluorescence intensity of Indocyanine Green (ICG) dynamically over a time period of 360 seconds. Analysis of the signal intensity within multiple regions of both hands was calculated and time-dependent perfusion curves for each region of interest were plotted over …time. RESULTS: Compared to the healthy, vascular non-impaired segments, pathological segments with an impaired tissue perfusion were identified through a decreased rate of early tissue enhancement (p = 0.02) and increased signal intensity of the optical perfusion agent per second (p < 0.001). The affected segments showed a decreased maximum signal intensity and a prolonged interval to reach the maximum signal intensity (time to peak). CONCLUSION: 2D FOI allows quantitative assessment of the peripheral microcirculation in various vascular pathophysiologies and is able to detect the impaired tissue perfusion in patients with vascular disorders of the upper extremity. Show more
Keywords: Fluorescence optical imaging, microcirculation, peripheral arterial occlusive disease, indocyanine green
DOI: 10.3233/CH-170321
Citation: Clinical Hemorheology and Microcirculation, vol. 70, no. 1, pp. 69-81, 2018
Authors: Angermann, Susanne | Schier, Johannes | Baumann, Marcus | Steubl, Dominik | Hauser, Christine | Lorenz, Georg | Günthner, Roman | Braunisch, Matthias C. | Kemmner, Stephan | Satanovskij, Robin | Haller, Bernhard | Heemann, Uwe | Lehnert, Thomas | Bieber, Richard | Pachmann, Martin | Braun, Jürgen | Scherf, Julia | Schätzle, Gabriele | Fischereder, Michael | Grimmer, Timo | Schmaderer, Christoph
Article Type: Research Article
Abstract: Background: The prevalence of cognitive impairment in hemodialysis patients is notably high. In previous studises performed in the general population, cognitive impairment has been associated with increased mortality. Objective: We evaluated the relationship between global cognitive function tested by a short screening instrument and mortality in hemodialysis patients. Methods: Cognitive testing was performed in 242 maintenance hemodialysis patients under standardized conditions at baseline using the Montreal Cognitive Assessment (MoCA). Cognitive impairment was defined as a MoCA test score ≤24 points, as published previously. All-cause mortality was monitored during a median follow-up of 3.54 years. Kaplan-Meier plot and Cox regression model …adjusted for known risk factors for mortality in hemodialysis patients were used to examine a possible association between global cognitive function and all-cause mortality. Results: A MoCA test score ≤24 points resulted in a significant almost 3-fold higher hazard for all-cause mortality (unadjusted hazard ratio [HR]: 2.812; 95% confidence interval [95% CI]: 1.683–4.698; p < 0.001). After adjustment, this association was attenuated but remained significant (adjusted HR: 1.749; 95% CI: 1.007–3.038; p = 0.047). Conclusion: Impairment of global cognitive function measured by a short screening instrument was identified for the first time as an independent predictor of all-cause mortality in hemodialysis patients. Thus, implementing the MoCA test in clinical routine could contribute to a better risk stratification of this patient population. Show more
Keywords: Cognitive dysfunction, hemodialysis, Montreal Cognitive Assessment, mortality
DOI: 10.3233/JAD-180767
Citation: Journal of Alzheimer's Disease, vol. 66, no. 4, pp. 1529-1537, 2018