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Medicine Sep 2023This is the first meta-analysis conducted to compare the hippocampal volume measured by magnetic resonance imaging (MRI) in healthy normal subjects, mild cognitive... (Meta-Analysis)
Meta-Analysis
BACKGROUND
This is the first meta-analysis conducted to compare the hippocampal volume measured by magnetic resonance imaging (MRI) in healthy normal subjects, mild cognitive impairment (MCI) and Alzheimer disease (AD), and to analyze the relationship between hippocampal volume changes and MCI and AD.
METHODS
English literatures published from January 2004 to December 2006 were extracted from PubMed, Embase, Wanfang Medical, and China National Knowledge Infrastructure databases. Statistical analysis was carried out with Stata/SE 16.0 software.
RESULTS
The smaller the volume of the hippocampus measured by MRI, the more severe the cognitive impairment or AD. Different MRI post-measurement correction methods have different measurement results: Left hippocampal volume measured by MRI Raw volume method is negatively correlated with MCI and AD (OR [odds ratio] = 0.58, 95%CI [confidence interval]: 0.42, 0.75) right hippocampal volume measured was not associated with MCI OR AD (OR = 0.87, 95%CI: 0.56, 1.18); left hippocampal volume measured by MRI total intracranial volume (TIV) Correction was not associated with MCI and AD (OR = 0.90, 95%CI: 0.62, 1.19), measured right hippocampal volume was not associated with MCI OR AD (OR = 0.81, 95%CI: 0.49, 1.12); left hippocampal volume measured by MRI TIV Correction was not associated with MCI and AD (OR = 0.90, 95%CI: 0.62, 1.19), measured right hippocampus volume was negatively associated with MCI and AD (OR = 0.49, 95%CI: 0.35, 0.62).
CONCLUSION
The shrinkage of hippocampus volume is closely related to MCI and AD. MRI measurement of hippocampus volume is not only an auxiliary diagnostic tool for MCI and AD, but also a good prognosis assessment tool.
Topics: Humans; Alzheimer Disease; Hippocampus; Cognitive Dysfunction; Temporal Lobe; China
PubMed: 37682140
DOI: 10.1097/MD.0000000000034997 -
Psychoneuroendocrinology Nov 2023Childhood adversity increases the risk of developing psychosis, but the biological mechanisms involved are unknown. Disaggregating early adverse experiences into core... (Review)
Review
Childhood adversity increases the risk of developing psychosis, but the biological mechanisms involved are unknown. Disaggregating early adverse experiences into core dimensions of deprivation and threat may help to elucidate these mechanisms. We therefore systematically searched the literature investigating associations between deprivation and threat, and neural, immune and stress hormone systems in individuals on the psychosis spectrum. Our search yielded 74 articles, from which we extracted and synthesized relevant findings. While study designs were heterogeneous and findings inconsistent, some trends emerged. In psychosis, deprivation tended to correlate with lower global cortical volume, and some evidence supported threat-related variation in prefrontal cortex morphology. Greater threat exposure was also associated with higher C-reactive protein, and higher and lower cortisol measures. When examined, associations in controls were less evident. Overall, findings indicate that deprivation and threat may associate with partially distinct biological mechanisms in the psychosis spectrum, and that associations may be stronger than in controls. Dimensional approaches may help disentangle the biological correlates of childhood adversity in psychosis, but more studies are needed.
Topics: Humans; Psychotic Disorders; Prefrontal Cortex; Hydrocortisone; Adult Survivors of Child Abuse
PubMed: 37651860
DOI: 10.1016/j.psyneuen.2023.106371 -
Neuroscience and Biobehavioral Reviews Feb 2024Subjective cognitive decline (SCD) is a risk factor for future cognitive impairment and dementia. It is uncertain whether the neurodegeneration of the cholinergic system... (Review)
Review
BACKGROUND
Subjective cognitive decline (SCD) is a risk factor for future cognitive impairment and dementia. It is uncertain whether the neurodegeneration of the cholinergic system is already present in SCD individuals. We aimed to review the current evidence about the association between SCD and biomarkers of degeneration in the cholinergic system.
METHOD
Original articles were extracted from three databases: Pubmed, Web of Sciences, and Scopus, in January 2023. Two researchers screened the studies independently.
RESULTS
A total of 11 research articles were selected. SCD was mostly based on amnestic cognitive complaints. Cholinergic system biomarkers included neuroimaging markers of basal forebrain volume, functional connectivity, transcranial magnetic stimulation, or biofluid. The evidence showed associations between basal forebrain atrophy, poorer connectivity of the cholinergic system, and SCD CONCLUSIONS: Degenerative changes in the cholinergic system can be present in SCD. Subjective complaints may help when identifying individuals with brain changes that are associated with cognitive impairment. These findings may have important implications in targeting individuals that may benefit from cholinergic-target treatments at very early stages of neurodegenerative diseases.
Topics: Humans; Neuroimaging; Cognitive Dysfunction; Alzheimer Disease; Basal Forebrain; Biomarkers; Cholinergic Agents; Magnetic Resonance Imaging
PubMed: 38220033
DOI: 10.1016/j.neubiorev.2024.105534 -
Medicine Aug 2023Sleep disorders significantly affect the quality of life in Parkinson disease (PD) patients. Deep brain stimulation of the subthalamic nucleus has been reported to... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Sleep disorders significantly affect the quality of life in Parkinson disease (PD) patients. Deep brain stimulation of the subthalamic nucleus has been reported to improve motor symptoms and decrease medication usage. However, the impact of subthalamic nucleus deep brain stimulation (STN-DBS) on sleep quality in PD patients remains to be definitively determined. This systematic review and meta-analysis, conducted following the preferred reporting items for systematic reviews and meta-analyses guidelines, aimed to clarify the effect of STN-DBS on sleep quality in PD patients.
METHODS
A rigorous literature search identified 6 studies, including 1 randomized controlled trial and 5 self-controlled trials, totaling 154 patients who underwent deep brain stimulation, providing 308 pairs of data for analysis. Parkinson disease sleep scale was the primary measure of interest, while the Movement Disorder Society-sponsored revision of the unified Parkinson disease rating scale was documented in all trials. Study quality was assessed using the Newcastle-Ottawa scale.
RESULTS
STN-DBS significantly improved Parkinson disease sleep scale scores (mean difference = 20.41, 95% CI: [13.03, 27.79], I² = 60.8%, P < .001), indicating enhanced sleep quality. Furthermore, a significant reduction in movement disorder society unified Parkinson disease rating scale part III scores postoperatively (mean difference = -12.59, 95% CI: [-14.70, -10.49], I² = 89.9%, P < .001) suggested improved motor function. PD medication usage was also significantly reduced postoperatively (mean difference = -314.71, 95% CI: [-468.13, -161.28], I² = 52.9%, P < .001). A sensitivity analysis confirmed the robustness of the main findings. The sample size was adequate, allowing for conclusive inferences.
CONCLUSION
The present study, which comprises a comprehensive systematic review and meta-analysis, offers compelling evidence that STN-DBS can ameliorate sleep quality, augment motor function, and curtail medication consumption among individuals afflicted with PD.
Topics: Humans; Subthalamic Nucleus; Parkinson Disease; Deep Brain Stimulation; Quality of Life; Sleep; Treatment Outcome; Randomized Controlled Trials as Topic
PubMed: 37565888
DOI: 10.1097/MD.0000000000034509 -
NeuroImage Nov 2023Electric field (E-field) modeling is a potent tool to estimate the amount of transcranial magnetic and electrical stimulation (TMS and tES, respectively) that reaches...
BACKGROUND
Electric field (E-field) modeling is a potent tool to estimate the amount of transcranial magnetic and electrical stimulation (TMS and tES, respectively) that reaches the cortex and to address the variable behavioral effects observed in the field. However, outcome measures used to quantify E-fields vary considerably and a thorough comparison is missing.
OBJECTIVES
This two-part study aimed to examine the different outcome measures used to report on tES and TMS induced E-fields, including volume- and surface-level gray matter, region of interest (ROI), whole brain, geometrical, structural, and percentile-based approaches. The study aimed to guide future research in informed selection of appropriate outcome measures.
METHODS
Three electronic databases were searched for tES and/or TMS studies quantifying E-fields. The identified outcome measures were compared across volume- and surface-level E-field data in ten tES and TMS modalities targeting two common targets in 100 healthy individuals.
RESULTS
In the systematic review, we extracted 308 outcome measures from 202 studies that adopted either a gray matter volume-level (n = 197) or surface-level (n = 111) approach. Volume-level results focused on E-field magnitude, while surface-level data encompassed E-field magnitude (n = 64) and normal/tangential E-field components (n = 47). E-fields were extracted in ROIs, such as brain structures and shapes (spheres, hexahedra and cylinders), or the whole brain. Percentiles or mean values were mostly used to quantify E-fields. Our modeling study, which involved 1,000 E-field models and > 1,000,000 extracted E-field values, revealed that different outcome measures yielded distinct E-field values, analyzed different brain regions, and did not always exhibit strong correlations in the same within-subject E-field model.
CONCLUSIONS
Outcome measure selection significantly impacts the locations and intensities of extracted E-field data in both tES and TMS E-field models. The suitability of different outcome measures depends on the target region, TMS/tES modality, individual anatomy, the analyzed E-field component and the research question. To enhance the quality, rigor, and reproducibility in the E-field modeling domain, we suggest standard reporting practices across studies and provide four recommendations.
Topics: Humans; Reproducibility of Results; Brain; Cerebral Cortex; Electricity; Gray Matter; Transcranial Magnetic Stimulation; Transcranial Direct Current Stimulation
PubMed: 37716590
DOI: 10.1016/j.neuroimage.2023.120379 -
Journal of Psychiatry & Neuroscience :... 2024Transcranial magnetic stimulation (TMS) is a noninvasive neurostimulation modality that has been used to study human synaptic plasticity. Leveraging work in ex vivo...
BACKGROUND
Transcranial magnetic stimulation (TMS) is a noninvasive neurostimulation modality that has been used to study human synaptic plasticity. Leveraging work in ex vivo preparations, mechanistically informed pharmacological adjuncts to TMS have been used to improve our fundamental understanding of TMS-induced synaptic plasticity.
METHODS
We systematically reviewed the literature pairing pharmacological adjuncts with TMS plasticity-induction protocols in humans. We searched MEDLINE, PsycINFO, and Embase from 2013 to Mar. 10, 2023. Studies published before 2013 were extracted from a previous systematic review. We included studies using repetitive TMS, theta-burst stimulation, paired associative stimulation, and quadripulse stimulation paradigms in healthy and clinical populations.
RESULTS
Thirty-six studies met our inclusion criteria (28 in healthy and 8 in clinical populations). Most pharmacological agents have targeted the glutamatergic -methyl-d-aspartate (NMDA; 15 studies) or dopamine receptors (13 studies). The NMDA receptor is necessary for TMS-induced plasticity; however, sufficiency has not been shown across protocols. Dopaminergic modulation of TMS-induced plasticity appears to be dose-dependent. The GABAergic, cholinergic, noradrenergic, and serotonergic neurotransmitter systems have small evidence bases supporting modulation of TMS-induced plasticity, as do voltage-gated calcium and sodium channels. Studies in clinical populations suggest that pharmacological adjuncts to TMS may rescue motor cortex plasticity, with implications for therapeutic applications of TMS and a promising clinical trial in depression.
LIMITATIONS
This review is limited by the predominance in the literature of studies with small sample sizes and crossover designs.
CONCLUSION
Pharmacologically enhanced TMS largely parallels findings from ex vivo preparations. As this area expands and novel targets are tested, adequately powered samples in healthy and clinical populations will inform the mechanisms of TMS-induced plasticity in health and disease.
Topics: Humans; Transcranial Magnetic Stimulation; Neuronal Plasticity; Motor Cortex; Dopamine; Calcium; Evoked Potentials, Motor
PubMed: 38359933
DOI: 10.1503/jpn.230090 -
Neuroscience and Biobehavioral Reviews Feb 2024Reactive response inhibition cancels impending actions to enable adaptive behavior in ever-changing environments and has wide neuropsychiatric implications. A canonical... (Review)
Review
Reactive response inhibition cancels impending actions to enable adaptive behavior in ever-changing environments and has wide neuropsychiatric implications. A canonical paradigm to measure the covert inhibition latency is the stop-signal task (SST). To probe the cortico-subcortical network underlying motor inhibition, transcranial magnetic stimulation (TMS) has been applied over central nodes to modulate SST performance, especially to the right inferior frontal cortex and the presupplementary motor area. Since the vast parameter spaces of SST and TMS enabled diverse implementations, the insights delivered by emerging TMS-SST studies remain inconclusive. Therefore, a systematic review was conducted to account for variability and synthesize converging evidence. Results indicate certain protocol specificity through the consistent perturbations induced by online TMS, whereas offline protocols show paradoxical effects on different target regions besides numerous null effects. Ancillary neuroimaging findings have verified and dissociated the underpinning network dynamics. Sources of heterogeneity in designs and risk of bias are highlighted. Finally, we outline best-practice recommendations to bridge methodological gaps and subserve the validity as well as replicability of future work.
Topics: Humans; Transcranial Magnetic Stimulation; Motor Cortex; Inhibition, Psychological; Neuroimaging; Task Performance and Analysis
PubMed: 38194868
DOI: 10.1016/j.neubiorev.2023.105532 -
World Neurosurgery Apr 2024With no cure for Alzheimer disease (AD), current efforts involve therapeutics that prevent further cognitive impairment. Deep brain stimulation (DBS) has been studied... (Review)
Review
OBJECTIVE
With no cure for Alzheimer disease (AD), current efforts involve therapeutics that prevent further cognitive impairment. Deep brain stimulation (DBS) has been studied for its potential to mitigate AD symptoms. This systematic review investigates the efficacy of current and previous targets for their ability to slow cognitive decline in treating AD.
METHODS
A systematic review of the literature was performed through a search of the PubMed, Scopus, and Web of Science databases. Human studies between 1994 and 2023 were included. Sample size, cognitive outcomes, and complications were recorded for each study.
RESULTS
Fourteen human studies were included: 7 studies with 6 distinct cohorts (n = 56) targeted the fornix, 6 studies with 3 distinct cohorts (n = 17) targeted the nucleus basalis of Meynert (NBM), and 1 study (n = 3) investigated DBS of the ventral striatum (VS). The Alzheimer's Disease Assessment Scale-Cognitive Subscale, Mini-Mental State Examination, and Clinical Dementia Rating Scale Sum of Boxes were used as the primary outcomes. In 5 of 6 cohorts where DBS targeted the fornix, cognitive decline was slowed based on the Alzheimer's Disease Assessment Scale-Cognitive Subscale or Mini-Mental State Examination scores. In 2 of 3 NBM cohorts, a similar reduction was reported. When DBS targeted the VS, the patients' Clinical Dementia Rating Scale Sum of Boxes scores indicated a slowed decline.
CONCLUSIONS
This review summarizes current evidence and addresses variability in study designs regarding the therapeutic benefit of DBS of the fornix, NBM, and VS. Because of varying study parameters, varying outcome measures, varying study durations, and limited cohort sizes, definitive conclusions regarding the utility of DBS for AD cannot be made. Further investigation is needed to determine the safety and efficacy of DBS for AD.
Topics: Humans; Alzheimer Disease; Deep Brain Stimulation; Basal Nucleus of Meynert; Cognitive Dysfunction; Outcome Assessment, Health Care
PubMed: 38141755
DOI: 10.1016/j.wneu.2023.12.083 -
European Radiology Jul 2024Cytotoxic lesions of the corpus callosum (CLOCC) are a common magnetic resonance imaging (MRI) finding associated with various systemic diseases including COVID-19.... (Review)
Review
OBJECTIVES
Cytotoxic lesions of the corpus callosum (CLOCC) are a common magnetic resonance imaging (MRI) finding associated with various systemic diseases including COVID-19. Although an increasing number of such cases is reported in the literature, there is a lack of systematic evidence summarizing the etiology and neuroimaging findings of these lesions. Thus, the aim of this systematic review was to synthesize the applied nomenclature, neuroimaging and clinical features, and differential diagnoses as well as associated disease entities of CLOCC.
MATERIALS AND METHODS
A comprehensive literature search in three biomedical databases identified 441 references, out of which 324 were eligible for a narrative summary including a total of 1353 patients.
RESULTS
Our PRISMA-conform systematic review identifies a broad panel of disease entities which are associated with CLOCC, among them toxic/drug-treatment-associated, infectious (viral, bacterial), vascular, metabolic, traumatic, and neoplastic entities in both adult and pediatric individuals. On MRI, CLOCC show typical high T2 signal, low T1 signal, restricted diffusion, and lack of contrast enhancement. The majority of the lesions were reversible within the follow-up period (median follow-up 3 weeks). Interestingly, even though CLOCC were mostly associated with symptoms of the underlying disease, in exceptional cases, CLOCC were associated with callosal neurological symptoms. Of note, employed nomenclature for CLOCC was highly inconsistent.
CONCLUSIONS
Our study provides high-level evidence for clinical and imaging features of CLOCC as well as associated disease entities.
CLINICAL RELEVANCE STATEMENT
Our study provides high-level evidence on MRI features of CLOCC as well as a comprehensive list of disease entities potentially associated with CLOCC. Together, this will facilitate rigorous diagnostic workup of suspected CLOCC cases.
KEY POINTS
• Cytotoxic lesions of the corpus callosum (CLOCC) are a frequent MRI feature associated with various systemic diseases. • Cytotoxic lesions of the corpus callosum show a highly homogenous MRI presentation and temporal dynamics. • This comprehensive overview will benefit (neuro)radiologists during diagnostic workup.
Topics: Humans; Corpus Callosum; Magnetic Resonance Imaging; COVID-19; Brain Diseases; Neuroimaging; Diagnosis, Differential
PubMed: 38147170
DOI: 10.1007/s00330-023-10524-3 -
Journal of Neurology Nov 2023Deep brain stimulation (DBS) is a well-established treatment that significantly improves the motor symptoms of patients with Parkinson's disease (PD); however, patients... (Review)
Review
Deep brain stimulation (DBS) is a well-established treatment that significantly improves the motor symptoms of patients with Parkinson's disease (PD); however, patients may experience post-operative psychological distress and social maladjustments. This phenomenon has been shown to be related to patients' pre-operative cognitive representations, such as expectations. In this systematic review, we discuss the findings on the role of the expectations of patients with PD regarding the clinical outcomes of DBS to identify areas of intervention to improve pre-operative patient education and promote successful post-operative psychosocial adjustment. PubMed was searched for relevant articles published up to 16 January 2023. Of the 84 identified records, 10 articles focusing on the treatment expectations of patients with PD undergoing DBS were included in this review. The selected studies were conducted among cohorts of patients with different DBS targets, among which the most common was the bilateral subthalamic nucleus. Overall, the data showed that patients' expectations contribute to treatment efficacy. Experiments investigating the placebo effect itself have shown clinical improvement after the induction of positive therapeutic expectations; conversely, unrealistic treatment expectations can affect patient satisfaction after surgery, clinical outcomes, and subjective well-being. This review highlights the need for routine clinical practice to better investigate and manage patients' pre-operative expectations, as well as multidisciplinary education to improve patient satisfaction and psychosocial adjustment after DBS.
Topics: Humans; Parkinson Disease; Deep Brain Stimulation; Motivation; Subthalamic Nucleus; Treatment Outcome
PubMed: 37517038
DOI: 10.1007/s00415-023-11898-6