58 research outputs found
Motor cognition in patients treated with subthalamic nucleus deep brain stimulation: Limits of compensatory overactivity in Parkinson's disease
Recent fMRI findings revealed that impairment in a serial prediction task in patients suffering from Parkinson's disease (PD) results from hypoactivity of the SMA. Furthermore, hyperactivity of the lateral premotor cortex sustained performance after withdrawal of medication. To further explore these findings, we here examined the impact of deep brain stimulation of the subthalamic nucleus on the activity of the putamen and premotor areas while performing the serial prediction task. To this end, we measured eight male PD patients ON and OFF deep brain stimulation and eight healthy age-matched male controls using [15O] water positron emission tomography to measure regional cerebral blood flow. As expected, PD patients showed poorer performance than healthy controls while performance did not differ between OFF and ON stimulation. Hypoactivity of the putamen and hyperactivity of the left lateral premotor cortex was found in patients compared to controls. Lateral premotor hyperactivity further increased OFF compared to ON stimulation and was positively related to task performance. These results confirm that the motor loop's dysfunction has impact on cognitive processes (here: prediction of serial stimuli) in PD. Extending prior data regarding the role of the lateral premotor cortex in cognitive compensation, our results indicate that lateral premotor cortex hyperactivity, while beneficial in moderate levels of impairment, might fail to preserve performance in more severe stages of the motor loop's degeneration
Successful deep brain stimulation of the nucleus accumbens in severe alcohol dependence is associated with changed performance monitoring
Item does not contain fulltextFollowing recent advances in neuromodulation therapy for mental disorders, we treated one patient with severe alcohol addiction with deep brain stimulation (DBS) of the nucleus accumbens (NAc). Before and one year following the surgery, we assessed the effects of DBS within the NAc on the addiction as well as on psychometric scores and electrophysiological measures of cognitive control. In our patient, DBS achieved normalization of addictive behavior and craving. An electrophysiological marker of error processing (the error-related negativity) linked to anterior midcingulate cortex (aMCC) functioning was altered through DBS, an effect that could be reversed by periods without
stimulation. Thus, this case supports the hypothesis that DBS of the NAc could have a positive effect on addiction trough a normalization of craving associated with aMCC dysfunction
Detection of dairy fouling by cyclic voltammetry and square wave voltammetry
Abstract Fouling in food processing environment can cause the increase of production costs due to additional cleaning steps and risk of contamination of food products. There is a demand to introduce advanced techniques to detect fouling in food processing equipment. Cyclic voltammetry (CV) and square wave voltammetry (SWV) were probed in this work to detect the dairy fouling and the reconstructed dairy emulsion by platinum‐based interdigitated microelectrodes. The results demonstrated that both methods can potentially be used for the fouling detection, since the attachment of fouling to the microelectrode surface leads to lower current responses compared to the clean microelectrodes
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