ABSTRACT
BACKGROUND: Inconsistent changes of cognitive functioning have been reported in patients with Parkinson disease (PD) with deep brain stimulation (DBS) of the subthalamic nucleus (STN). To investigate the underlying pathomechanisms, we correlated alterations of cognitive test performance and changes of neuronal energy metabolism in frontal basal ganglia projection areas under bilateral STN stimulation. METHODS: We conducted verbal fluency, learning, and memory tests and 18-fluorodeoxyglucose (FDG) PET in nine patients with PD with STN-DBS before and 6 months after surgery. Using coregistered MRI, postoperative changes of the normalized cerebral metabolic rates of glucose (nCMRGlc) in the dorsolateral prefrontal cortex (DLPFC), lateral orbitofrontal cortex (LOFC), ventral and dorsal cingulum (v/dACC), and in Broca area were determined and correlated with alterations of neuropsychological test results. RESULTS: After surgery, highly variable changes of both cognitive test performance and frontal nCMRGlc values were found with significant correlations between verbal fluency and FDG uptake in the left DLPFC (Brodmann area [BA] 9, 46), left Broca area (BA 44/45), and the right dACC (BA 32). A decrease of nCMRGlc in the left OFC (BA 11/47) and dACC (BA 32) correlated with a decline of verbal learning. All patients showed reduced metabolic activity in the right anterior cingulate cortex after DBS. Baseline cognitive abilities did not predict verbal learning or fluency changes after surgery. CONCLUSIONS: These data show a significant linear relationship between changes in frontal 18-fluorodeoxyglucose PET activity and changes in cognitive outcome after deep brain stimulation of the subthalamic nucleus (STN) in advanced Parkinson disease. The best correlations were found in the left frontal lobe (dorsolateral prefrontal cortex and Broca area). Baseline performance on cognitive tests did not predict cognitive or metabolic changes after STN electrode implantation.
Subject(s)
Cognition/physiology , Deep Brain Stimulation/methods , Frontal Lobe/diagnostic imaging , Parkinson Disease/therapy , Positron-Emission Tomography , Subthalamic Nucleus/physiology , Aged , Chi-Square Distribution , Confidence Intervals , Female , Fluorodeoxyglucose F18 , Follow-Up Studies , Frontal Lobe/pathology , Humans , Linear Models , Magnetic Resonance Imaging/methods , Male , Middle Aged , Neuropsychological Tests , Odds Ratio , Parkinson Disease/diagnostic imaging , Parkinson Disease/pathology , Parkinson Disease/physiopathology , Subthalamic Nucleus/diagnostic imagingABSTRACT
Blood group serological diagnosis in cats is clinically relevant for the prophylaxis of blood group incompatibility reactions. In permanent blood donors, cats used for breeding and recipients with a history of prior blood transfusions, testing should consist of blood typing and antibody detection. As test sera and test cells are not commercially available and since parallel tests for various antibody qualities are necessary, they are usually performed in specialized laboratories. Incompatibility testing has a practical clinical relevance in finding a serological diagnosis before each blood transfusion and in cases of kitten mortality. In emergency situations, cross matching can be performed on slides as a screening test. Negative slide test results then should be verified using the more sensitive test tube or microtiter plate tests.
