Reorganization of brain connectivity across the spectrum of clinical cognitive decline.

Clinical cognitive decline, leading to Alzheimer's Disease Dementia (ADD), has long been interpreted as a disconnection syndrome, hindering the information flow capacity of the brain, hence leading to the well-known symptoms of ADD. The structural and functional brain connectome analyses play a central role in studies of brain from this perspective. However, most current research implicitly assumes that the changes accompanying the progression of cognitive decline are monotonous in time, whether measured across the entire brain or in fixed cortical regions.

Volumetric and functional connectivity changes of the thalamic nuclei in different stages of Alzheimer's disease.

Objective: Memory processes known to be impaired in Alzheimer's disease (AD) are maintained by a large-scale neurocognitive network with subcortical components, including the thalamus. Therefore, we aimed to examine the volumetric and functional changes of the thalamic nuclei at different scales across AD stages.

Methods: MRI data of patients diagnosed with 20 AD dementia (ADD), 30 amnestic mild cognitive impairment (MCI), and 30 subjective cognitive impairment (SCI) were used.

Siamese Graph Convolutional Network quantifies increasing structure-function discrepancy over the cognitive decline continuum.

Background And Objective: Alzheimer's disease dementia (ADD) is well known to induce alterations in both structural and functional brain connectivity. However, reported changes in connectivity are mostly limited to global/local network features, which have poor specificity for diagnostic purposes. Following recent advances in machine learning, deep neural networks, particularly Graph Neural Network (GNN) based approaches, have found applications in brain research as well.

Remote Neuropscyhological Assessment: Teleneuropsychology.

Introduction: Teleneuropsychology, which includes the remote application of neuropsychological tests to patients via telephone or videoconferencing, can expand access to health services for patients who reside in distant areas or have mobility restrictions. With the emergence of the COVID-19 pandemic, there has been a significant increase in the use of teleneuropsychology in cognitive assessment. In this review, the aim was to critically review the results of studies conducted in the field of teleneuropsychology and the fundamental principles related to tele-neuropsychological assessment.

Cognitive deficits and cortical volume loss in COVID-19-related hyposmia.

Background And Purpose: Studies have found that up to 73% of COVID-19 patients experience hyposmia. It is unclear if the loss of smell in COVID-19 is due to damage to the peripheral or central mechanisms. This study aimed to explore the impacts of COVID-19-induced hyposmia on brain structure and cognitive functions.

Shrinkage of olfactory amygdala connotes cognitive impairment in patients with Parkinson's disease.

Unlabelled: During the caudo-rostral progression of Lewy pathology, the amygdala is involved relatively early in Parkinson's disease (PD). However, lesser is known about the volumetric differences at the amygdala subdivisions, although the evidence mainly implicates the olfactory amygdala. We aimed to investigate the volumetric differences between the amygdala's nuclear and sectoral subdivisions in the PD cognitive impairment continuum compared to healthy controls (HC).

An Investigation of Affective Personality Traits in Alzheimer's Disease: SEEKING as a Possible Predictor for Early-Stage Alzheimer's Dementia.

Objective: The aim of the current study was to investigate affective personality traits in Alzheimer's disease, a neurodegenerative condition mainly characterized by episodic memory impairment.

Method: The sample included 69 participants from 3 diagnostic categories. Twenty-five participants were diagnosed with subjective cognitive impairment (SCI), 26 participants were diagnosed with mild cognitive impairment of the amnestic type (aMCI), and the remaining 18 participants were diagnosed with early-stage Alzheimer's dementia (ADD).

Morphometric analysis of medial temporal lobe subregions in Alzheimer's disease using high-resolution MRI.

The spread pattern of progressive degeneration seen in Alzheimer's disease (AD) to small-scale medial temporal lobe subregions is critical for early diagnosis. In this context, it was aimed to examine the morphometric changes of the hippocampal subfields, amygdala nuclei, entorhinal cortex (ERC), and parahippocampal cortex (PHC) using MRI. MRI data of patients diagnosed with 20 Alzheimer's disease dementia (ADD), 30 amnestic mild cognitive impairment (aMCI), and 30 subjective cognitive impairment (SCI) without demographic differences were used.

Altered learning and transfer abilities in Korsakoff's syndrome depending on task complexity.

Korsakoff's syndrome (KS) is characterized by episodic memory impairment due to damage to the medial diencephalic structures. Although commonly associated with chronic alcoholism, starvation due to the hunger strike is one of its nonalcoholic causes. Learning the stimulus-response associations and transferring the just-learned associations to novel combinations were previously tested by specific tasks in memory-impaired patients with hippocampal, basal forebrain, and basal ganglia damage.

Brain reserve contributes to distinguishing preclinical Alzheimer's stages 1 and 2.

Background: In preclinical Alzheimer's disease, it is unclear why some individuals with amyloid pathologic change are asymptomatic (stage 1), whereas others experience subjective cognitive decline (SCD, stage 2). Here, we examined the association of stage 1 vs. stage 2 with structural brain reserve in memory-related brain regions.

Eating Difficulties and Relationship With Nutritional Status Among Patients With Dementia.

Background: One of the most common behavioral problems in patients with dementia is eating problems, which are known to increase the risk of malnutrition. However, few studies have been conducted in this patient group regarding the relationship between eating difficulties and nutritional status.

Purpose: This study was designed to determine the eating difficulties faced by patients with dementia and to evaluate the relationship in this population between eating difficulties and malnutrition.

Disconnection Syndromes.

In this review, the history and current status of the topic of disconnection syndromes, which was introduced to the discipline of Behavioral Neurology by the founding father Norman Geschwind and that has become the dominant paradigm for the explanation of neuropsychiatric disorders with new developments, like network connectivity imaging in the living human brain are discussed.

Neuropsychiatric outcomes and caregiver distress in primary progressive aphasia.

Background: In this study, we aimed to outline the neuropsychiatric consequences of primary progressive aphasia (PPA) and to understand how neuropsychiatric symptomatology affects distress in caregivers.

Methods: The Neuropsychiatric Inventory (NPI) including the distress index (NPI-Distress) was used. Additional information about the caregiver burden was obtained using Zarit Burden Interview (ZBI).

Effect of Dopaminergic Therapy on Impulse Control Disorders in Patients With a Prolactinoma.

Background: Studies have reported an increase in the incidence of impulse control disorders (ICDs) in patient groups treated with dopamine agonists (DAAs), especially in Parkinson disease (PD). However, very few studies have reported on ICDs in individuals with a prolactinoma who were treated with DAAs.

Objective: To see whether a DAA by itself causes ICDs in individuals with a prolactinoma by controlling the susceptibility to impulsivity by excluding individuals with other risk factors for ICDs.

Identification of metabolic correlates of mild cognitive impairment in Parkinson's disease using magnetic resonance spectroscopic imaging and machine learning.

Objective: To investigate metabolic changes of mild cognitive impairment in Parkinson's disease (PD-MCI) using proton magnetic resonance spectroscopic imaging (H-MRSI).

Methods: Sixteen healthy controls (HC), 26 cognitively normal Parkinson's disease (PD-CN) patients, and 34 PD-MCI patients were scanned in this prospective study. Neuropsychological tests were performed, and three-dimensional H-MRSI was obtained at 3 T.

Genotype-Phenotype correlations of SCARB2 associated clinical presentation: a case report and in-depth literature review.

Background: Biallelic pathogenic variants in the SCARB2 gene have been associated with action myoclonus-renal failure (AMRF) syndrome. Even though SCARB2 associated phenotype has been reported to include typical neurological characteristics, depending on the localization and the feature of the pathogenic variants, clinical course and the presentations have been shown to differ.

Case Presentation: Whole exome sequencing (WES) analysis revealed a homozygous truncating variant (p.

Medication management and treatment adherence in Parkinson's disease patients with mild cognitive impairment.

Introduction: The key feature that distinguishes mild cognitive impairment (MCI) from dementia is the absence of significant functional decline because of cognitive impairment. In Parkinson's disease patients (PD) with MCI (PD-MCI), the effect of cognitive impairment on complex instrumental daily activities, such as medication management, is not well established.

Method: 26 patients with PD-MCI (diagnosed to Level 2 Movement Disorders Society diagnostic criteria) and 32 idiopathic PD patients without cognitive impairment participated in the study.

Verbal and Nonverbal Memory in Neurodegenerative and Stroke Aphasia: Evidence From the Turkish Version of the Three Words Three Shapes Test.

Background: Although language impairment is the most salient feature of cognitive impairment in both primary progressive aphasia (PPA) and stroke aphasia (SA), memory can also be impaired in both patient populations.

Objective: To identify distinctive features of verbal and nonverbal memory processing in individuals with PPA and those with SA.

Method: We gave individuals with PPA (n = 14), those with SA (n = 8), and healthy controls (HC; n = 13) a comprehensive neuropsychological test battery and the Turkish version of the Three Words Three Shapes Test (3W3S-Turkish).

Default mode and dorsal attention network involvement in visually guided motor sequence learning.

Motor sequence learning (MSL) paradigms are often used to investigate the neural processes underlying the acquisition of complex motor skills. Behavioral and neuroimaging studies have indicated an early stage in which spatial learning is prominent and a late stage of automatized performance after multiple training periods. Functional magnetic resonance imaging (fMRI) studies yielded both decreased and increased activations of the sensorimotor and association areas.

Clinical and molecular genetic findings of hereditary Parkinson's patients from Turkey.

Introduction: The majority of Parkinson's disease (PD) ensue late-onset with a complex spectrum of environmental and genetic risk factors. Awareness of genetic causes in patients with PD is essential for genetic counseling and future genotype-oriented therapeutic developments.

Methods: Large pathogenic changes in eight PD-related genes and small pathogenic sequence variants in 22 PD-related genes were investigated simultaneously in 82 PD patients from 79 families where clinical evaluations were performed.