[Differentiation between mild cognitive impairment and healthy elderly population using neuropsychological tests]. / Az enyhe kognitív deficitben szenvedok differenciálása az egészséges idos populációtól neuropszichológiai tesztek segítségével.

OBJECTIVE: Paired Associates Learning (PAL) test assesses brain functions in those brain regions affected earliest by Alzheimer's dementia. The aim of the present study was to assess the usability of our implementation of the PAL test for screening mild cognitive impairment. METHODOLOGY: Based on Petersen criteria, 14 out of the 63 subjects were diagnosed with mild cognitive impairment. Visuospatial learning was assessed by our implementation of PAL test. The ability of the PAL test to differentiate between study groups was compared to the Addenbrook Cognitive Examination (ACE) and to the Mini Mental State Examination (MMSE). Linear logistic regression was used for statistical analysis, and the results are presented as Receiver Operating Characteristics (ROC) curves. All analyses were performed by SAS 9.2. RESULTS: All the results of neuropsychological tests differed significantly between the study groups. However, considerable difference could be detected between the tests regarding specificity and sensitivity. The PAL test reached the sensitivity of the ACE, while its specificity was slightly under the ACE. DISCUSSION: The PAL test developed in the framework of the present study is found to be able to differentiate between MCI and healthy controls. It outperformed the MMSE in terms of sensitivity and specificity, while it needs comparable time to perform. Its sensitivity, the important parameter for screening, is comparable to ACE, while it needs significantly shorter time and less assistance.

Selected Aspects of Using the Telemetry Method in Synthesis of RelNav System for Air Traffic Control.

Accuracy is an important factor in air traffic management which is why high requirements are necessary for each navigation system. The aim of this article is to describe the principles of the RelNav system and telemetry and their accuracy. We present the algorithms of the relative navigation system, which could be used for air traffic control in the case of the unavailability of satellite navigation system signals. This article sums up the different positioning methods, and deals with the accuracy of the relative navigation system (RelNav). Furthermore, the article considers the factors that influence the positioning accuracy. For this task, a computer simulation was created to evaluate the accuracy of the telemetric method. Next, we discuss the principles of telemetry and algorithms for calculating the position of the flying object (FO).

Five-year outcomes in cardiac surgery patients with atrial fibrillation undergoing concomitant surgical ablation versus no ablation. The long-term follow-up of the PRAGUE-12 Study.

BACKGROUND: The long-term effect of concomitant surgical ablation (SA) on clinical outcomes in an unselected population of patients has not been sufficiently reported in randomized studies. OBJECTIVE: The aim of this study was to assess clinical outcomes of the SA after 5 years of follow-up. METHODS: The PRAGUE-12 study was a prospective, randomized clinical trial assessing cardiac surgery with ablation for AF vs cardiac surgery alone. Patients with AF who were also indicated for cardiac surgery (coronary artery disease [CAD], valve surgery) were randomized to SA or control (no ablation) group. All patients were followed for 5 years. The primary endpoint was a composite of cardiovascular death, stroke, hospitalization for heart failure, or severe bleeding. Secondary endpoint was a recurrence of AF. RESULTS: A total of 207 patients were analyzed (SA group = 108 patients, control group = 99 patients). Both groups were similar relative to important clinical characteristics except for CAD, which was more common in the control group. Cumulative incidence curves showed a higher incidence of the primary endpoint in the control group (P = .024, Gray's test). However, after adjusting for all covariables, the difference between groups was not significant (subhazard ratio [SHR] 0.69 [0.47-1.02], P = .068). The incidence of stroke and AF recurrences were significantly reduced in the SA group, and remained significant even after adjustment for all covariables, including CAD (stroke: SHR 0.32 [0.12-0.84], P = .02, AF recurrences: SHR 0.44 [0.31-0.62], P < .001). CONCLUSIONS: Concomitant SA of AF is associated with a greater likelihood of maintaining sinus rhythm and a decreased risk of stroke.

Monitoring the early signs of cognitive decline in elderly by computer games: an MRI study.

BACKGROUND: It is anticipated that current and future preventive therapies will likely be more effective in the early stages of dementia, when everyday functioning is not affected. Accordingly the early identification of people at risk is particularly important. In most cases, when subjects visit an expert and are examined using neuropsychological tests, the disease has already been developed. Contrary to this cognitive games are played by healthy, well functioning elderly people, subjects who should be monitored for early signs. Further advantages of cognitive games are their accessibility and their cost-effectiveness. PURPOSE: The aim of the investigation was to show that computer games can help to identify those who are at risk. In order to validate games analysis was completed which measured the correlations between results of the 'Find the Pairs' memory game and the volumes of the temporal brain regions previously found to be good predictors of later cognitive decline. PARTICIPANTS AND METHODS: 34 healthy elderly subjects were enrolled in the study. The volume of the cerebral structures was measured by MRI. Cortical reconstruction and volumetric segmentation were performed by Freesurfer. RESULTS: There was a correlation between the number of attempts and the time required to complete the memory game and the volume of the entorhinal cortex, the temporal pole, and the hippocampus. There was also a correlation between the results of the Paired Associates Learning (PAL) test and the memory game. CONCLUSIONS: The results gathered support the initial hypothesis that healthy elderly subjects achieving lower scores in the memory game have increased level of atrophy in the temporal brain structures and showed a decreased performance in the PAL test. Based on these results it can be concluded that memory games may be useful in early screening for cognitive decline.