Publications by authors named "Halil A Velioglu"

Depressive cognitive impairment is seen in a significant number of patients with depression. However, it remains challenging to differentiate between patients with amnestic (those with subjective cognitive impairment complaints) and non-amnestic major depressive disorder, highlighting the urgent need for additional objective tools to help classify these patients more accurately. We analyzed cognitive state, alterations in regional entropy and functional connectivity measures of the brain between patients with major depression and healthy controls.

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Background: Cerebellar dysfunction is strongly implicated in both cognitive impairments and psychosis, and the cognitive dysmetria hypothesis posits cognition as the intermediary in the pathway from cerebellar dysfunction to psychopathology. However, the nuanced cerebellum-behavior relationships in psychosis remain unclear. Establishing such a link is crucial to understand cerebellar mechanisms and to identify treatment targets for cognitive deficits in patients.

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Visual hallucinations (VH) are common in Parkinson's disease (PD), yet their mechanisms remain poorly understood. Several studies have investigated structural brain correlates of Parkinsonian VH, but critical gaps in knowledge persist. An inverse relationship between auditory hallucinations and paracingulate sulcus (PCS) length, associated with reality-monitoring mechanisms, has been reported.

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Background: The cerebellum has traditionally been associated with motor functions, but recent evidence highlights its critical role in cognitive and emotional regulation, contributing to the neuropathology of schizophrenia. Our previous data-driven research demonstrated that cerebellar-cortical functional connectivity can predict antipsychotic treatment outcomes in first-episode psychosis (FEP). The present study aimed to investigate specific cerebellar functional systems involved in treatment prediction.

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Introduction: Type 2 diabetes mellitus is a ubiquitous chronic inflammatory disease with deleterious effects on various tissues, including the kidney, retina, and peripheral nerves. Studies using histopathology and magnetic resonance imaging have revealed that diabetes-related chronic hyperglycemia may impact the brain's essential functioning by causing microvascular damage. The aim of this study was to examine the cognitive functioning of type 2 diabetic individuals with and without retinopathy by evaluating their morphological, structural, and biochemical differences.

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Parkinson's disease is primarily marked by mitochondrial dysfunction and metabolic abnormalities. We recently reported that the combined metabolic activators improved the immunohistochemical parameters and behavioural functions in Parkinson's disease and Alzheimer's disease animal models and the cognitive functions in Alzheimer's disease patients. These metabolic activators serve as the precursors of nicotinamide adenine dinucleotide and glutathione, and they can be used to activate mitochondrial metabolism and eventually treat mitochondrial dysfunction.

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The etiology of cognitive decline linked to migraine remains unclear, with a growing recurrence rate and potential increased dementia risk among sufferers. Cognitive dysfunction has recently gained attention as a significant problem among migraine sufferers that can be related to alterations in hippocampal function and structure. This study explores hippocampal subfield connectivity and volume changes in migraine patients.

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Objective: The pathophysiology behind memory impairment in Parkinson's Disease Mild Cognitive Impairment (PD-MCI) is unclear. This study aims to investigate the hippocampal and cortical atrophy patterns in PD-MCI patients with different types of memory impairments, categorized as Retrieval Failure (RF) and Encoding Failure (EF).

Methods: The study included 16 healthy controls (HC) and 34 PD-MCI patients, divided into RF (N = 18) and EF (N = 16) groups based on their Verbal Memory Processes Test (VMPT) scores, including spontaneous recall, recognition, and Index of Sensitivity to Cueing (ISC).

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Objective: This study examines the effect of smoking on global and regional brain entropy in patients with Major Depressive Disorder (MDD), aiming to elucidate the relationship between smoking habits and brain network complexity in depression.

Methods: The study enrolled 24 MDD patients, divided into smokers and non-smokers, from Alanya Alaaddin Keykubat University and Istanbul Medipol University. Resting-state fMRI data were acquired and processed.

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Major depressive disorder (MDD) is a debilitating illness that includes depressive mood. Repetitive Transcranial Magnetic Stimulation (rTMS) is a therapy method used in the treatment of MDD. The purpose of this study was to assess neurotrophic factors, and oxidative stress levels in MDD patients and evaluate the changes in these parameters as a result of rTMS therapy.

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The latest research into the pathophysiology of Alzheimer's Disease (AD) has included several cognitive deficits related to hippocampal functioning. However, current clinical research fails to consider the full extent of the heterogeneous cognitive spectrum of AD, resulting in a lack of the specific methods required to draw definitive diagnostic and therapeutic conclusions. This also includes in-vivo metabolic measurements for tailoring the diagnostic and therapeutic regimens in humans with AD.

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Aim: Although there exists substantial epidemiological evidence indicating an elevated risk of dementia in individuals with diabetes, our understanding of the neuropathological underpinnings of the association between Type-2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) remains unclear. This study aims to unveil the microstructural brain changes associated with T2DM in AD and identify the clinical variables contributing to these changes.

Methods: In this retrospective study involving 64 patients with AD, 31 individuals had concurrent T2DM.

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Introduction: Emotionally driven cognitive complaints represent a major diagnostic challenge for clinicians and indicate the importance of objective confirmation of the accuracy of depressive patients' descriptions of their cognitive symptoms.

Methods: We compared cognitive status and structural and functional brain connectivity changes in the pulvinar and hippocampus between patients with total depression and healthy controls. The depressive group was also classified as "amnestic" or "nonamnestic," based on the members' subjective reports concerning their forgetfulness.

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Background: Repetitive transcranial magnetic stimulation (rTMS) has emerged as a promising alternative therapy for Alzheimer's disease (AD) due to its ability to modulate neural networks and enhance cognitive function. This treatment offers the unique advantage of enabling real-time monitoring of immediate cognitive effects and dynamic brain changes through electroencephalography (EEG).

Objective: This study focused on exploring the effects of left parietal rTMS stimulation on visual-evoked potentials (VEP) and visual event-related potentials (VERP) in AD patients.

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Background: Transient receptor potential (TRP) channels have been found to have significant implications in neuronal outgrowth, survival, inflammatory neurogenic pain, and various epileptogenic processes. Moreover, there is a growing body of evidence indicating that transient receptor potential (TRP) channels have a significant impact on epilepsy and its drug-resistant subtypes.

Objective: We postulated that Gb 761 would modulate TRPA1 channels, thereby exhibiting anti-inflammatory and neuroprotective effects in a neuroblastoma cell line.

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Although no longer considered a public health threat, post-COVID cognitive syndrome continues to impact on a considerable proportion of individuals who were infected with COVID-19. Recent studies have also suggested that COVID may be represent a critical risk factor for the development of Alzheimer's disease (AD). We compared 17 COVID patients with 20 controls and evaluated the effects of COVID-19 on general cognitive performance, hippocampal volume, and connections using structural and seed-based connectivity analysis.

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Introduction: Alzheimer's disease (AD) is one of the pathologies that the scientific world is still desperate for. The aim of this study was the investigation of diazepam binding inhibitor (DBI) as a prognostic factor for AD prognosis.

Methods: A total of 120 participants were divided into 3 groups.

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Purpose: Neuroimaging studies have shown that anosmia is accompanied by a decreased olfactory bulb volume, yet little is known about alterations in cerebral and cerebellar lobule volumes. The purpose of this study was to investigate structural brain alterations in anosmic patients.

Methods: Sixteen anosmic patients (mean age 42.

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Brain temperature determines not only an individual's cognitive functionality but also the prognosis and mortality rates of many brain diseases. More specifically, brain temperature not only changes in response to different physiological events like yawning and stretching, but also plays a significant pathophysiological role in a number of neurological and neuropsychiatric illnesses. Here, we have outlined the function of brain hyperthermia in both diseased and healthy states, focusing particularly on the amyloid beta aggregation in Alzheimer's disease.

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Article Synopsis
  • Alzheimer's disease is linked to metabolic issues, and a study with combined metabolic activators (CMA) showed improvements in AD symptoms in rats, helping with mitochondrial function and reducing oxidative stress.
  • A phase-II clinical trial on AD patients tested CMA against a placebo, focusing on cognitive function and daily living activities, along with safety and plasma metabolite analysis.
  • Results showed a significant improvement in cognitive scores in the CMA group compared to placebo, with additional changes in brain imaging and better levels of certain proteins and metabolites related to metabolism.
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Exosomes are potent mediators of physiological and pathological processes. In Alzheimer's disease and inflammatory disorders, due to exosomes' distinctive ability to cross the blood-brain barrier, a bidirectional communication between the periphery and the central nervous system exists. Since exosomes can carry various biochemical molecules, this review investigates the role of exosomes as possible mediators between chronic systemic inflammatory diseases and Alzheimer's disease.

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Background: Neurodegenerative diseases (NDDs), including Alzheimer's disease (AD) and Parkinson's disease (PD), are associated with metabolic abnormalities. Integrative analysis of human clinical data and animal studies have contributed to a better understanding of the molecular and cellular pathways involved in the progression of NDDs. Previously, we have reported that the combined metabolic activators (CMA), which include the precursors of nicotinamide adenine dinucleotide and glutathione can be utilized to alleviate metabolic disorders by activating mitochondrial metabolism.

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In Alzheimer's disease (AD), structural and functional changes in the brain may give rise to disruption of specific cognitive functions. The aim of this study is to investigate the functional connectivity alterations in the pulvinar's subdivisions and total pulvinar voxel-based morphometry (VBM) changes in individuals with AD and healthy controls. A seed-based functional connectivity analysis was applied to the anterior, inferior, lateral, and medial pulvinar in each hemisphere.

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