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Results for “Cognitive Dysfunction”

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At least 19 recordsLinked to original sources
PubMed2026

Impact of a multimodal prehabilitation program on postoperative cognitive dysfunction: a single-center randomized controlled trial.

BACKGROUND: Postoperative cognitive dysfunction (POCD) is a frequent complication after cardiac surgery. Exercise-based prehabilitation may enhance functional reserve and reduce vulnerability to perioperative cerebral insults. We hypothesized that multimodal prehabilitation reduces POCD 3&#xa0;months after cardiac surgery. METHODS: This prespecified substudy of a single-center randomized controlled trial (NCT03466606) included patients aged &#x2265;50&#xa0;years undergoing elective coronary artery bypass grafting and/or valve surgery. Participants were randomized 1:1 to 4-6&#xa0;weeks of multimodal prehabilitation (exercise training, nutritional support, and psychological support) or standard preoperative care. Cognitive function was assessed at baseline and 3&#xa0;months postoperatively using an age- and education-adjusted neuropsychological battery. POCD was defined as performance &#x2265;1.5 standard deviations below normative values in at least 2 cognitive tests, excluding the Mini-Mental State Examination. Logistic regression analyses were performed to evaluate factors associated with POCD. RESULTS: Of 160 participants screened from the parent trial, 134 met eligibility criteria for the substudy and were randomized; 116 completed 3-month follow-up (prehabilitation n&#xa0;=&#xa0;53; control n&#xa0;=&#xa0;63). POCD occurred in 29 patients (25%), including 15/53 (28%) in the prehabilitation group and 14/63 (22%) in controls (odds ratio [OR] 1.37, 95% confidence interval [CI] 0.54-3.50, P&#xa0;=&#xa0;0.52). In multivariable analysis, preoperative cognitive impairment was independently associated with POCD (OR 13.28, 95% CI 4.06-43.41, P&#xa0;<&#xa0;0.001), whereas prehabilitation was not (OR 1.09, 95% CI 0.35-3.45, P&#xa0;=&#xa0;0.877). Higher physical activity levels at 3&#xa0;months were associated with lower odds of POCD (OR 0.97, 95% CI 0.95-1.00, P&#xa0;=&#xa0;0.047). CONCLUSIONS: In this randomized controlled trial, a 4-6-week multimodal prehabilitation program did not reduce postoperative cognitive dysfunction 3&#xa0;months after cardiac surgery. Although the intervention did not achieve measurable cognitive protection, the observed association between postoperative physical activity levels and postoperative cognitive dysfunction warrants further investigation.

Humans↗
PubMed1975

A developmental approach to delineate components of cognitive dysfunction in schizophrenia.

Two developmentally based tests were devised to study the nature of schizophrenic cognitive dysfunction within a psychopharmacolgical framework and to relate the data to developmental and psychophysiological models. The Colour-Form Preference Test was designed to evaluate cognitive style in terms of early maturational stages and provided a subscale for assessing arousal-related cognitive growth. The Egocentricity of Thought Test, adapted from Piaget's developmental study of right-left positional concepts, enabled investigation in terms of the later stages of cognitive growth. These and other clinical measures were taken of schizophrenic patients at various points of treatment and also administered to a non-psychotic comparison group. Test results supported their validity, reliability, longitudinal sensitivity and capacity for nosological and prognostic discriminations. The data also suggested a distinction between two components of schizophrenic cognitive dysfunction -- one drug-sensitive, which could be considered as arousal-related, and the other drug-resistant, which might best be described as developmental. A two-factor model encompassing the psychophysiological and developmental hypotheses is thus offered as a more comprehensive representation of the cognitive disorder.

Acute Disease↗
PubMed1977

Schizophrenic cognitive dysfunction: a deficit in rule transfer.

This study examined conceptual rule learning (RL) deficit in male schizophrenic Ss categorized into three groups as defined by Whitaker Index of Schizophrenic Thinking (WIST). Ss were administered a conjunctive, disjunctive, conditional or biconditional rule learning task, WIST, and Shipley-Hartford Memory Scale. It was shown that: (a) the WIST reliably differentiates among three levels of thought disorder as reflected by a deficit in inter-problem transfer of rule learning; (b) certain WIST and Shipley parameters reliably predict RL performance; and (c) phenothiazine dosage levels show no influence on the WIST and no correlation with RL. The findings indicate that cognitive dysfunction in schizophrenics is evidenced by limited inductive reasoning, insufficient channel capacity for filtering out irrelevant information, and inability to gain from antecedent RL experience. Principal locus of schizophrenic thought disorder is examined within a stimulus encoding-information processing paradigm.

Adult↗
PubMed1975

Delayed hypoxic encephalopathy without cognitive dysfunction.

Three days after an episode of hypoxia, a 20-year-old man developed profound motor deficit in the absence of behavioral or cognitive disturbance. Previous reviews of delayed hypoxic encephalopathy have stressed behavioral and cognitive disturbances as the initial symptoms. This patient's pyramidal tract dysfunction in the absence of higher cortical dysfunction serves to illustrate that delayed hypoxic encephalopathy is predominantly a white matter rather than a gray matter disorder.

Adult↗
PubMed2026

CNNM2 in schizophrenia: multilevel evidence of genetic susceptibility, magnesium homeostasis, neurodevelopment and cognitive dysfunction.

Schizophrenia (SCZ) is a common psychiatric disorder with a complex, genetically and environmentally influenced etiology, but the specific pathogenesis remains unclear. In recent years, the SCZ susceptibility gene CNNM2 (encoding cyclin M2) located at the 10q24.32-33 locus has received widespread attention. The well-validated SCZ risk interval 10q24.32-33 harbors two independent risk variants: rs11191580 in NT5C2 (significantly associated with CNNM2 mRNA and protein levels) and rs7914558 in CNNM2. Results from functional genomic analyses indicate that lower CNNM2 expression is significantly associated with SCZ. Imaging genetics studies have demonstrated that carriers of risk alleles of CNNM2 SNPs exhibit alterations in brain structure. Animal model studies have revealed that Cnnm2 downregulation in mice leads to impairments in sensorimotor gating and cognitive function. As an Mg2+ transporter, CNNM2 primarily maintains systemic Mg2+ homeostasis. According to clinical studies, a proportion of patients with SCZ exhibit reduced Mg2+ concentrations in plasma and cerebrospinal fluid. CNNM2 dysfunction may contribute to the pathology of SCZ by disrupting Mg2+ homeostasis, thereby affecting neurodevelopment and synaptic plasticity. A systematic consolidation of current evidence supporting the involvement of CNNM2 in SCZ pathogenesis provides a direction for further investigation of the pathological mechanisms underlying this disease, and for identification of novel targets for clinical intervention..

Schizophrenia↗
PubMed1979

Single case study. Pseudodementia and mania.

This case report extends the discussion of pseudodementia into the area of manic behavior. An elderly patient whose manic symptoms are considered to be an early sign of an organic brain syndrome should be given timely repeat evaluations before this diagnosis is allowed to guide treatment. Our case presentation emphasized the paucity of the data base we have to diagnose cognitive and emotional disturbances of the elderly. It is difficult to identify the essential features of cognitive dysfunction associated with primary neuronal degeneration especially in the early stages of the disease. A careful differential diagnostic evaluation is important to eliminate variables such as affective disorders and underlying physical conditions as causes of confusion and cognitive dysfunction in the elderly patient.

Bipolar Disorder↗
PubMed2026

Downregulation of Trpv4 and Klf2 in brain microvessels is associated with the progression of neurovascular dysfunction and cognitive impairment in a model of heart failure with preserved ejection fraction.

Vascular cognitive impairment (VCI) shares major risk factors with heart failure with preserved ejection fraction (HFpEF), including obesity, diabetes and hypertension. Yet VCI research often relies on single-stimulus models, whereas patients experience combined risk factors. We therefore assessed cerebrovascular and cognitive phenotypes in an HFpEF model and investigated underlying mechanisms. Male Lean and Obese ZSF1 rats underwent longitudinal assessments of blood pressure, glucose, cardiac function and behavioural performance. Cerebral blood flow and neurovascular coupling were assessed by laser speckle contrast imaging. White matter integrity, blood-brain barrier (BBB) permeability and vascular density were analyzed by (immuno)histochemistry. Cortical microvessels were isolated for transcriptomic profiling, and selected targets were validated using multiplex in-situ hybridization. Obese rats exhibited neurovascular uncoupling and impaired short- and long-term memory and spatial learning, accompanied by brain atrophy and reduced myelin. BBB permeability increased at 22-23&#x2009;weeks and vascular density at 34-35&#x2009;weeks in Obese versus Lean rats. Transcriptomic analysis of brain microvessels revealed altered processes related to angiogenesis, vasoreactivity, immune mechanisms and vascular remodelling, with consistent downregulation of Trpv4 and Klf2. Obese ZSF1 rats develop progressive neurovascular dysfunction associated with HFpEF onset and reduced Trpv4 and Klf2 expression in cerebral microvessels, two key vasoprotective genes.

Diastolic dysfunction↗
PubMed2026

Ultra-high-field 7T MRI reveals neural abnormalities of attention networks in relation to cognitive impairment in hypertension.

Hypertension is a significant risk factor for cognitive impairment (CI), yet the corresponding neural network abnormalities remain underexplored. In this study, we examined the associations among global and domain-specific cognitive dysfunction, neuroimaging measures, and blood pressure in a subgroup of hypertensive patients with CI (N&#xa0;=&#xa0;41) from a randomized controlled trial who underwent ultra-high-field 7&#xa0;T MRI. Structural atrophy related to CI was localized to regions overlapping the attention networks. Both whole-brain and within-network dysfunction of the attention networks were associated with worse global cognitive performance. Notably, hyperconnectivity within key attention network hubs, including the right anterior insula and posterior intraparietal sulcus, was associated with declined processing speed in hypertensive patients, mediating the association between pulse pressure and processing speed. These findings provide new insights into the neural pathophysiology of hypertension-related CI and suggest potential network-based targets for intervention.

Magnetic Resonance Imaging↗
PubMed2025

GHSR suppression in neurons protects against aging-associated metabolic and cognitive impairments.

Aging is accompanied by progressive declines in metabolic and cognitive functions. Growth hormone secretagogue receptor (GHSR), a receptor for the gut hormone ghrelin, is highly expressed in neurons and plays a crucial role in metabolic regulation. We previously reported that aged global GHSR-ablated mice are lean and insulin-sensitive, and that neuronal GHSR-deleted mice (Syn1-cre;Ghsrf/f) completely prevent diet-induced obesity. However,&#xa0;the role of neuronal&#xa0;GHSR in metabolic and cognitive aging has not been elucidated. The current study aims to determine the roles of neuronal GHSR in aging metabolism and cognitive dysfunction. Syn1-cre;Ghsrf/f mice were subjected to cold stress, glucose- and insulin-tolerance tests, behavioral tests, and tissue analysis. Aging is accompanied by glycemic dysregulation and insulin resistance; old Syn1-cre;Ghsrf/f mice showed improved glucose tolerance and insulin sensitivity. Aging is associated with thermogenic impairment and cognitive decline; old Syn1-cre;Ghsrf/f mice showed better cold resistance and retained better recognition memory. Noticeably,&#xa0;there were&#xa0;increased expression of thermogenic makers (PGC1&#x3b1; and UCP1) and elevated sympathetic innervation markers (tyrosine hydroxylase and synaptophysin) in brown adipose tissue of old Syn1-cre;Ghsrf/f mice. Lastly, old Syn1-cre;Ghsrf/f mice exhibited decreased pro-inflammatory cytokines and increased neural plasticity-related markers (brain-derived neurotrophic factor, synaptophysin, and tyrosine hydroxylase) in metabolic and cognitive-relevant brain regions such as hypothalamus, cortex, and hippocampus. In conclusion, neuronal inhibition of GHSR promotes a healthy aging phenotype showing improved energy metabolism and cognitive function, which is likely contributed to the improved thermogenesis and insulin sensitivity, reduced inflammation, and restored neuronal plasticity.

Animals↗
PubMed2026

Acute COVID-19 severity and impaired cognitive function up to 32&#xa0;months after diagnosis: an observational study.

BACKGROUND: Cognitive dysfunction ("brain fog") is a commonly reported post-COVID-19 symptom. Leveraging data from five general population cohorts across four European countries (Estonia, Iceland, Norway, and Sweden), we assessed long-term prevalence of impaired subjective cognitive function among individuals diagnosed with COVID-19 by acute illness severity. METHODS: The included cohorts consisted of adult participants recruited from March 2020 and followed with self-report measures of cognitive function and past COVID-19 infection (except one cohort consisting of clinically confirmed COVID-19 cases) through February 2023. In a cross-sectional analysis we contrasted the prevalence of impaired cognitive function among individuals with and without a COVID-19 diagnosis, overall and by illness severity up to 32&#xa0;months post-diagnosis. We adjusted for age, gender, education, relationship status, binge drinking, body mass index, previous psychiatric diagnosis, number of chronic medical conditions, and response period. In a longitudinal analysis, we assessed potential changes in cognitive function scores before and after COVID-19 diagnosis. RESULTS: The study population consisted of 153,841 participants (71% women), with 31,359 (20.4%) reporting a positive COVID-19 test. Overall, a COVID-19 diagnosis was not statistically significantly associated with increased prevalence ratio (PR) of impaired cognitive function (PR 1.30 [95% CI: 0.98-1.71]). Individuals bedridden due to COVID-19 for 1-6&#xa0;days (PR 1.38 [95% CI 0.96-1.99]) or&#x2009;&#x2265;&#x2009;7&#xa0;days (2.59 [1.55-4.33]) had higher prevalence of impaired cognitive function compared to those never diagnosed, while individuals never bedridden had a lower prevalence to those never diagnosed with COVID-19 (0.89 [0.80-1.00]). These findings were corroborated in the longitudinal analysis where a pre- to post diagnosis decline in cognitive function was observed among individuals bedridden due to COVID-19 (p&#x2009;<&#x2009;0.0001). CONCLUSIONS: The data indicates that a severe COVID-19 acute illness course is associated with impaired cognitive function up to 18-32&#xa0;months after COVID-19 diagnosis.

Adult↗
PubMed1975

Colour form representation test: a developmental method for the study of cognition in schizophrenia.

The Colour Form Representation Test (CFR) was devised as one of a series of developmentally rooted objective measures of schizophrenic cognitive dysfunction. Based on the observations of Piaget and others in relation to the conceptual use of colour, form and representational cues, it provided a four-level response hierarchy corresponding to the preverbal and early verbal stages of cognitive growth. The CFR was tested with 66 schizophrenics and 42 non-psychotic subjects and found to distinguish between these two groups and among schizophrenic subtypes. It showed significant correlations with measures of cognitive and attentional dysfunction and, longitudinally, was observed to be a reliable instrument that reflected the differential therapeutic outcome of various schizophrenic groups. The research potential of the CFR and its relevance to developmental and psychophysiological theories of schizophrenic cognitive disorder were discussed.

Adolescent↗
PubMed2026

Potential contribution of the microbiota-gut-brain axis to doxorubicin-associated cognitive impairment: Mechanisms, evidence, and therapeutic opportunities.

Chemotherapy-induced cognitive impairment (CICI), often termed chemobrain, is a clinically important complication of cancer treatment that can affect memory, attention, executive function, and processing speed during and after therapy. Doxorubicin is of particular mechanistic interest because brain parenchymal exposure is limited, yet preclinical studies consistently identify neuroinflammatory, oxidative, vascular, and synaptic abnormalities after treatment. This critical narrative review evaluates whether intestinal injury and disruption of the microbiota-gut-brain axis may contribute to these central effects. Preclinical evidence indicates that doxorubicin can alter microbial community structure, injure the intestinal barrier, modify SCFA-associated taxa or predicted functions, alter selected metabolite profiles, and promote systemic inflammatory and metabolic signaling. These peripheral changes could interact with brain endothelial cells, glia, mitochondria, hippocampal neurogenesis, and synaptic-plasticity pathways. However, the proposed doxorubicin-gut-brain pathway remains a predominantly preclinical and incompletely tested framework. No longitudinal human study has yet established, within the same patients, the temporal sequence linking doxorubicin exposure, microbiome or metabolome changes, systemic inflammation, and objective cognitive outcomes. Existing animal studies also vary in dose, regimen, tumor context, sampling time, microbiome methodology, and control of behavioral or microbiological confounders, while causal rescue experiments remain limited. Key priorities are therefore longitudinal human cohorts with pretreatment baselines and repeated multi-omics and cognitive assessments; animal studies that test temporal precedence and causal rescue or pathway blockade in the same model; mediation analyses that determine whether microbial or metabolic changes lie between treatment and cognitive dysfunction; and mechanism-informed clinical trials that demonstrate target engagement, cognitive benefit, oncology safety, and preservation of antitumor efficacy. Microbiome-directed interventions are promising but remain investigational for doxorubicin-associated CICI.

blood&#x2013;brain barrier↗
PubMedDate not supplied

Visual and auditory cognitive processing affected by epilepsy.

Neuropsychological studies on epileptic patients may be expected to reveal specific cognitive dysfunction even in patients with normal general intellectual ability. Difficulties in cognitive processing by visual-spatial and auditory-verbal modes are indicated by this investigation employing the Wisconsin Card Sorting Test and the Token Test, with epileptics of normal intelligence. Impairment in capacity for sustained, focused attention significantly affects performance of epileptic patients on these clinical measures, and others as well which require vigilance and attention and sensory-perceptual discrimination.

Adult↗
PubMedDate not supplied

Visual and auditory cognitive processing affected by epilepsy.

Neuropsychological studies of epileptic patients may be expected to reveal specific cognitive dysfunction even in patients with normal general intellectual ability. Difficulties in cognitive processing by visual-spatial and auditory-verbal modes are indicated by this investigation employing the Wisconsin Card Sorting Test and the Token Test, with epileptics of normal intelligence. Impairment in capacity for sustained, focused attention significantly affects performance of epileptic patients on these clinical measures, and others as well which require vigilance and attention and sensory-perceptual discrimination.

Adult↗
PubMed2026

AI-Supported, Integrative Prediction of Postoperative Delirium: Protocol for the CONFUSED Study.

BACKGROUND: Postoperative delirium (POD) is a frequent and serious complication in older surgical patients, characterized by acute cognitive dysfunction and fluctuating levels of consciousness. POD is associated with prolonged hospitalization, long-term cognitive decline, reduced quality of life, and increased mortality. Despite its clinical relevance, the underlying pathophysiological mechanisms remain poorly understood, and reliable biomarkers for early prediction and prevention are lacking. OBJECTIVE: The CONFUSED study aims to identify molecular and clinical predictors of POD by integrating clinical data with proteomic, transcriptomic, and epigenetic analyses. The primary objective is to develop predictive models for POD using multimodal data. Secondary objectives include the identification of delirium-associated genes, proteins, and epigenetic signatures, as well as the exploration of patient subgroups at increased risk for POD. METHODS: CONFUSED is a prospective observational cohort study conducted at a German university hospital. Adult patients undergoing major surgery under general anesthesia will be enrolled until 100 cases of POD have been observed, which is expected to require a total sample size of approximately 200 to 300 patients. Blood samples are collected at 4 predefined time points: before premedication, immediately after surgery, and on postoperative days 2 and 5. Samples undergo comprehensive proteomic profiling, transcriptomic analysis using RNA microarrays, DNA methylation analysis, and genotyping of selected polymorphisms. Clinical data, including demographics, comorbidities, perioperative variables, medications, and delirium assessments using the Confusion Assessment Method (CAM) and CAM for the intensive care unit, are systematically recorded. Statistical analyses include univariate and multivariate methods, as well as machine learning approaches such as random forests and support vector machines, to identify relevant biomarkers and develop predictive models. The study protocol follows STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) and TRIPOD (Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis) guidelines and was approved by the responsible ethics committees. RESULTS: The study was registered in the German Clinical Trials Register (DRKS00033854) on March 18, 2024. Recruitment started in January 2024 and is ongoing at the time of manuscript submission. As of now, 135 patients have been enrolled. Sample collection and laboratory analyses are ongoing. Data analysis began in January 2026, with first results anticipated in July 2026. Final data lock is anticipated after the completion of recruitment. CONCLUSIONS: By integrating multimodal molecular data with clinical parameters and applying advanced machine learning techniques, the CONFUSED study aims to improve the prediction and understanding of POD. The results are expected to support the development of personalized preventive strategies and contribute to improved perioperative care for patients at risk of POD.

Humans↗
PubMed1978

Adaptational factors in memory function in the aged.

Memory function in the aged is described as due to the interaction of a number of variables in addition to physiology, including affective state and environmental conditions. Depression can cause a series of behavioral patterns ranging from exaggeration of memory complaint, to simulation of organic dysfunction, to "pseudodementia" in which there is production of an actual organic mental syndrome. Stress and noxious environmental conditions also contribute to cognitive dysfunction. Custodial care is singled out as especially harmful, producing a form of "excess disability" termed "unorientation" in which apparently impaired memory results from an apathetic, withdrawn reaction to the environment. All these adaptational patterns are subject to prevention, modification, and in some cases, reversal.

Adaptation, Psychological↗