A Virtual Reality-Based Screening Test for Cognitive Impairment in Small Vessel Disease.

BACKGROUND: There is a need for new practical tools to assess the cognitive impairment of small vessel disease (SVD) patients in the clinic. OBJECTIVE: This study aimed to examine cognitive functioning by administering the Virtual Supermarket (VST) in patients with SVD with cognitive impairment (SVD-CI, N = 32), cognitively normal SVD (SVD-CN, N = 37), and age-and education-matched healthy controls (HC, N = 30). METHODS: The tablet-based VST application and comprehensive traditional pencil-and-paper neuropsychological tests assessing memory, attention, executive function, visuospatial function, and language were administered to all participants. RESULTS: A moderate correlation was found between the "Duration" and "Correct Quantities" variables of VST and visuospatial function and general cognitive status composite Z scores across SVD-CI patients. "Duration" and "Correct Money" variables were moderately related to memory, executive functions, and visuospatial function composite Z scores across SVD-CN patients. A combination of all VST variables discriminated SVD-CI and HC with a correct classification rate of 81%, a sensitivity of 78%, and a specificity of 84%. CONCLUSION: This study is the first to evaluate cognitive functions employing the VST in SVD with and without cognitive impairment. It provides encouraging preliminary findings of the utility of the VST as a screening tool in the assessment of cognitive impairment and the differentiation of SVD patients from HC. In the future, validation studies of the VST with larger samples are needed.

Evaluation of Matrix Metalloproteinase-2 (MMP-2) and -9 (MMP-9) and Their Tissue Inhibitors (TIMP-1 and TIMP-2) in Plasma from Patients with Neurodegenerative Dementia.

Matrix metalloproteinases (MMPs) are substantial regulators of learning and memory and might be involved in neurodegeneration. It is known that MMPs are involved in pathogenesis of Alzheimer's disease (AD) and are particularly involved in the amyloid-ß processing pathway. However, information on circulating levels of these proteins and their tissue inhibitors (TIMPs) in AD and other neurodegenerative dementia (ND) diseases such as dementia with Lewy bodies (DLB) and frontotemporal dementia (FTD) is not clear. Therefore, this study was directed toward finding out how plasma levels of MMP-2, MMP-9, TIMP-1, and TIMP-2 vary in AD, DLB, and FTD; and investigating the correlation of the levels of MMPs and their inhibitors with clinical parameters of the patients. MMP-2, MMP-9, TIMP-1, and TIMP-2 levels were measured by enzyme linked immunosorbent assay (ELISA). Plasma MMP-2 levels were significantly lower in all the patient groups than in the age-matched healthy controls (HCs) (p < 0.05). MMP-9 levels were significantly lower in the FTD patients than in the HCs (p < 0.05). Also, TIMP-1 levels were lower in the AD and FTD patients than in the HCs (p < 0.05). TIMP-2 levels were similar in all the groups. These findings highlight the importance of circulating MMPs in ND and suggest that MMPs and their inhibitors might play a role in impaired amyloid-ß peptide metabolism which is responsible for the genesis and progression of ND. Furthermore, measurement of MMP-2 and MMP-9 and their inhibitors may be of great importance for large scale basic research and clinical studies of ND.

Patients with mild cognitive impairment display reduced auditory event-related delta oscillatory responses.

BACKGROUND: Event-related oscillations (ERO) may provide a useful tool for the identification of cognitive deficits in mild cognitive impairment (MCI) and Alzheimer's disease (AD). In the present study, we investigate peak-to-peak amplitude of auditory event-related delta oscillations of MCI subjects. METHOD: The study included twenty-two consecutive patients with MCI recruited in neurology clinic and 21 age- and education-matched normal elderly controls. A classical auditory oddball paradigm was used in the experiments. EEG was recorded from F3, Fz, F4, C3, Cz, C4, P3, Pz, P4, O1, Oz, and O2 locations. The maximum peak-to-peak amplitudes for each subject's averaged delta response (0.5-2.2 Hz) were measured. RESULTS: The amplitudes between groups differed significantly at the frontal and mid-centroparietal locations. ANOVA on delta responses revealed a significant effect for groups (F(1.41) = 4.84, P = 0.033), indicating a larger delta response for healthy controls than MCI subjects. Post hoc comparisons revealed that peak-to-peak delta response was significantly larger for healthy controls than for MCI over electrode sites F3, Fz, F4, Cz, C4, and Pz. DISCUSSION: Event-related delta frequency band seems to be the most affected oscillatory response in cognitive impairment due to AD. Therefore, it deserves to be investigated as a candidate electrophysiological biomarker in further studies.

Prevalence and risk factors of depression among community dwelling elderly.

Depression in the elderly is associated with increased morbidity and mortality. The purpose of this study was to determine the prevalence and risk factors of depression among community-dwelling older population in an urban setting in Turkey. This cross-sectional study was conducted among 482 elderly individuals 65 years and over in an urban area. Cluster sampling method was used for sample size. Depression in the elderly had been diagnosed by a clinical interview and Geriatric Depression Scale. Data were collected by door-to-door survey. Chi square test was used for statistical analysis. P value, which was calculated by the results of chi square test and coefficient of phi (φ), below 0.05 was included in the analysis of logistic regression. Depression was significantly associated with female gender, being single or divorced, lower educational status, low income, unemployment, and lack of health insurance. However, logistic regression analysis revealed higher depression rates in the elderly with chronic obstructive pulmonary disease, psychiatric disease, cerebrovascular disease, low income and being dependent. Depression is common among community-dwelling older people in an urban area of Izmir, Turkey. Older adults living in community should be cautiously screened to prevent or manage depression.

Beta oscillatory responses in healthy subjects and subjects with mild cognitive impairment.

The aim of the present study was to investigate the role of beta oscillatory responses upon cognitive load in healthy subjects and in subjects with mild cognitive impairment (MCI). The role of beta oscillations upon cognitive stimulation is least studied in comparison to other frequency bands. The study included 17 consecutive patients with MCI (mean age = 70.8 ± 5.6 years) according to Petersen's criteria, and 17 age- and education-matched normal elderly controls (mean age = 68.5 ± 5.5 years). The experiments used a visual oddball paradigm. EEG was recorded at 30 cortical locations. EEG-evoked power, inter-trial phase synchronization, and event-related beta responses filtered in 15-20 Hz were obtained in response to target and non-target stimuli for both groups of subjects. In healthy subjects, EEG-evoked beta power, inter-trial phase synchronization of beta responses and event-related filtered beta responses were significantly higher in responses to target than non-target stimuli (p < 0.05). In MCI patients, there were no differences in evoked beta power between target and non-target stimuli. Furthermore, upon presentation of visual oddball paradigm, occipital electrodes depict higher beta response in comparison to other electrode sites. The increased beta response upon presentation of target stimuli in healthy subjects implies that beta oscillations could shift the system to an attention state, and had important function in cognitive activity. This may, in future, open the way to consider beta activity as an important operator in brain cognitive processes.

Brain's alpha, beta, gamma, delta, and theta oscillations in neuropsychiatric diseases: proposal for biomarker strategies.

Brain oscillations have gained tremendous importance in neuroscience during recent decades as functional building blocks of sensory-cognitive processes. Research also shows that event-related oscillations (EROs) in "alpha," "beta," "gamma," "delta," and "theta" frequency windows are highly modified in pathological brains, especially in patients with cognitive impairment. The strategies and methods applied in the present report reflect the innate organization of the brain: "the whole brain work." The present paper is an account of methods such as evoked/event-related spectra, evoked/ERDs, coherence analysis, and phase-locking. The report does not aim to cover all strategies related to the systems theory applied in brain research literature. However, the essential methods and concepts are applied in several examples from Alzheimer's disease (AD), schizophrenia, and bipolar disorder (BD), and such examples lead to fundamental statements in the search for neurophysiological biomarkers in cognitive impairment. An overview of the results clearly demonstrates that it is obligatory to apply the method of oscillations in multiple electroencephalogram frequency windows in search of functional biomarkers and to detect the effects of drug applications. Again, according to the summary of results in AD patients and BD patients, multiple oscillations and selectively distributed recordings must be analyzed and should include multiple locations. Selective connectivity between selectively distributed neural networks has to be computed by means of spatial coherence. Therefore, by designing a strategy for diagnostics, the differential diagnostics, and application of (preventive) drugs, neurophysiological information should be analyzed within a framework including multiple methods and multiple frequency bands. The application of drugs/neurotransmitters gains a new impact with the analysis of oscillations and coherences. A more clear and differentiated analysis of drug effects can be attained in comparison to the application of the conventional wide-band evoked potential and event-related potential applications.

Comparison of cortical excitability in chronic migraine (transformed migraine) and migraine without aura. A transcranial magnetic stimulation study.

We studied the excitability of the motor cortex in patients with migraine without aura (MWOA) (n = 20) and with chronic migraine (CM) (n = 20) using transcranial magnetic stimulation (TMS). By using a 90-mm circular coil placed over the vertex and recording of the first dorsal interosseous muscle, we measured thresholds, latencies and amplitudes of motor evoked potentials and duration of cortical silent periods in patient groups and in controls (n = 20). No differences were found between groups for threshold, latency and amplitude values. However, the duration of the cortical silent period was longer in CM patients, being significantly different from both controls and MWOA. We suggest that either this difference in cortical excitability may develop during transformation from MWOA to CM or different pathophysiological mechanisms may play a role in these two headache syndromes.