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search.filters.applied.f.language: search.filters.language.engSubject: search.filters.subject.Alzheimer's disease

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    The Relationship Between the Degree of Cognitive Impairment and Retinal Nerve Fiber Layer Thickness
    (2015) Oktem, Ece Ozdemir; Derle, Eda; Kibaroglu, Seda; Oktem, Caglar; Akkoyun, Imren; Can, Ufuk; 0000-0002-2860-7424; 0000-0003-2122-1016; 0000-0001-8689-417X; 0000-0002-3964-268X; 25575807; AAK-7713-2021; AAI-8830-2021; AAJ-2999-2021; AAJ-2956-2021
    The goal of the present study is to investigate the relationship between the degree of cognitive impairment and retinal nerve fiber layer (RNFL) thickness which is measured by the optical coherence tomography (OCT). Thirty-five patients with Alzheimer's disease (AD), 35 patients with mild cognitive impairment (MCI), and 35 healthy volunteers, between the ages of 60-87, who were examined in the neurology outpatient clinic among 2012-2013 were prospectively involved in our study. Mini mental state examination (MMSE) test, montreal cognitive assessment (MOCA), and also neuropsychological test batteries were used for the neurocognitive evaluation. RNFL thickness was measured by the OCT technique and the differences among groups were studied. The relationship between RNFL thickness and MMSE scores with demographic characteristics was investigated. RNFL thickness was significantly lower in AD and MCI groups compared with the control group (p < 0.01). No significant differences of RNFL were found between the MCI and the AD groups (p > 0.05). Significant correlation was found between MMSE scores and the RNFL values (p < 0.05). Significant thinning in RNFL along with age was detected (p < 0.05). In our study, it is thought that retinal nerve fiber degeneration and central nervous system degeneration may be concurrent according to the thinning of RNFL measured by OCT in AD and MCI groups. RNFL measurement may also be useful for early diagnosis and evaluation of the disease progression. Further studies are needed to optimize the utility of this method as an ocular biomarker in AD.
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    PET Imaging in Neurology: Alzheimer's and Parkinson's Diseases
    (2015) Sarikaya, Ismet; 0000-0002-1087-580X; 25920047; G-7881-2015
    PET studies play an important role in the early detection of Alzheimer's and Parkinson's diseases (AD and PD). Fluorine-18 fluorodeoxyglucose (F-18-FDG) PET imaging of regional cerebral glucose metabolism and PET amyloid imaging are the two major PET studies for AD. F-18-FDG PET is highly sensitive for the early diagnosis of AD, in predicting conversion from mild cognitive impairment to AD, and in differentiating AD from other dementias. PET amyloid imaging is positive in the majority of patients with AD. Negative amyloid PET reduces the likelihood of AD. The main limitations of PET amyloid imaging is its high positivity in the normal elderly population and in other medical conditions with amyloid pathologies. Various PET tracers are available to assess motor and cognitive dysfunctions in PD. PET tracers targeting presynaptic dopaminergic function (F-18-DOPA, radiolabeled PET tracers assessing the availability of dopamine transporters and vesicular monoamine transporters) and postsynaptic dopamine receptors are used to assess motor dysfunction in PD. PET tracers, particularly dopamine transporters, are highly sensitive in the early diagnosis of PD. Uptake of PET tracers in the striatum is inversely correlated with disease severity. PET is valuable in differentiating PD from other movement disorders. PET studies, particularly F-18-FDG PET, help to evaluate cortical metabolism in PD patients with cognitive dysfunction and dementia.
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    A novel electroencephalography based approach for Alzheimer's disease and mild cognitive impairment detection
    (2021) Oltu, Burcu; Aksahin, Mehmet Feyzi; Kibaroglu, Seda; 0000-0002-3964-268X; AAJ-2956-2021
    Background and objective: Alzheimer's disease (AD) is characterized by cognitive, behavioral and intellectual deficits. The term mild cognitive impairment (MCI) is used to describe individuals whose cognitive impairment departing from their expectations for the age that does not interfere with daily activities. To diagnose these disorders, a combination of time-consuming, expensive tests that has difficulties for the target population are evaluated, moreover, the evaluation may yield subjective results. In the presented study, a novel methodology is developed for the automatic detection of AD and MCI using EEG signals. Methods: This study analyzed the EEGs of 35 subjects (16 MCI, 8 AD, 11 healthy control) with the developed algorithm. The algorithm consists of 3 methods for analysis, discrete wavelet transform(DWT), power spectral density (PSD) and coherence. In the first approach, DWT is applied to the signals to obtain major EEG sub-bands, afterward, PSD of each sub-band is calculated using Burg's method. In the second approach, interhemispheric coherence values are calculated. The variance and amplitude summation of each sub-bands' PSD and the amplitude summation of the coherence values corresponding to the major sub-bands are determined as features. Bagged Trees is selected as a classifier among the other tested classification algorithms. Data set is used to train the classifier with 5-fold cross-validation. Results: As a result, accuracy, sensitivity, and specificity of 96.5%, 96.21%, 97.96% are achieved respectively. Conclusion: In this study, we have investigated whether EEG can provide efficient clues about the neuropathology of Alzheimer's Disease and mild cognitive impairment for early and accurate diagnosis. Accordingly, a decision support system that produces reproducible and objective results with high accuracy is developed.
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    Examination of IL-1 beta level as an inflammasome marker in Alzheimer's disease
    (2019) Bulut, Onur; Tanburoglu, Anil; Boluk, Gulsah; Demir, Nurhak; Eren, Erden; Vurgun, Ufuk; Genc, Sermin; Yener, Gorsev
    Objective: Interleukin (IL)-1 beta is believed to be responsible for the neurotoxicity of amyloid plaques in Alzheimer's disease (AD). In the present study, serum levels of IL-1 beta, and correlations with clinical features and neuropsychiatric test results were examined. Methods: Thirty-eight patients with AD and 38 healthy control patients were included in the study. Serum IL-1 beta levels in patients with AD and control were analyzed using enzyme-linked immunosorbent assay method. The Mini-Mental Test Score (MMSE) and Geriatric Depression Scale (GDS) were administered to both the patient and control groups. Furthermore, the clinical dementia rating, detailed neuropsychological test battery, and neuropsychiatric inventory were administered to the AD group. It was determined that the serum IL-1 beta measurements of the patient and control groups were not statistically different, and IL-1 beta measurements in the patient group were not correlated with the MMSE and GDS. Results: The relationship of IL-1 beta measurements in the patient group with other clinical data was not significant. Among the patients' neuropsychological tests, a moderately, significant negative correlation was found only between the clock drawing test and visual learning score and serum IL-1 beta levels. Conclusion: Our study is in agreement with other studies in which no significant difference was found between patients with AD and healthy controls in terms of serum IL-1 beta levels, but the moderately negative correlation obtained with the clock drawing test and visual learning score indicates a weak relation. This result may indicate that stronger relations will be determined in large-scale studies involving larger numbers of patients.