scholarly journals Effects of Meditation on Structural Changes of the Brain in Patients With Mild Cognitive Impairment or Alzheimer’s Disease Dementia

2021 ◽  
Vol 15 ◽  
Author(s):  
Madhukar Dwivedi ◽  
Neha Dubey ◽  
Aditya Jain Pansari ◽  
Raju Surampudi Bapi ◽  
Meghoranjani Das ◽  
...  

Previous cross-sectional studies reported positive effects of meditation on the brain areas related to attention and executive function in the healthy elderly population. Effects of long-term regular meditation in persons with mild cognitive impairment (MCI) and Alzheimer’s disease dementia (AD) have rarely been studied. In this study, we explored changes in cortical thickness and gray matter volume in meditation-naïve persons with MCI or mild AD after long-term meditation intervention. MCI or mild AD patients underwent detailed clinical and neuropsychological assessment and were assigned into meditation or non-meditation groups. High resolution T1-weighted magnetic resonance images (MRI) were acquired at baseline and after 6 months. Longitudinal symmetrized percentage changes (SPC) in cortical thickness and gray matter volume were estimated. Left caudal middle frontal, left rostral middle frontal, left superior parietal, right lateral orbitofrontal, and right superior frontal cortices showed changes in both cortical thickness and gray matter volume; the left paracentral cortex showed changes in cortical thickness; the left lateral occipital, left superior frontal, left banks of the superior temporal sulcus (bankssts), and left medial orbitofrontal cortices showed changes in gray matter volume. All these areas exhibited significantly higher SPC values in meditators as compared to non-meditators. Conversely, the left lateral occipital, and right posterior cingulate cortices showed significantly lower SPC values for cortical thickness in the meditators. In hippocampal subfields analysis, we observed significantly higher SPC in gray matter volume of the left CA1, molecular layer HP, and CA3 with a trend for increased gray matter volume in most other areas. No significant changes were found for the hippocampal subfields in the right hemisphere. Analysis of the subcortical structures revealed significantly increased volume in the right thalamus in the meditation group. The results of the study point out that long-term meditation practice in persons with MCI or mild AD leads to salutary changes in cortical thickness and gray matter volumes. Most of these changes were observed in the brain areas related to executive control and memory that are prominently at risk in neurodegenerative diseases.

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Lili Nie ◽  
Zeyong Zhao ◽  
Xiantao Wen ◽  
Wei Luo ◽  
Tao Ju ◽  
...  

Abstract Background Previous studies of brain structure in methamphetamine users have yielded inconsistent findings, possibly reflecting small sample size and inconsistencies in duration of methamphetamine abstinence as well as sampling and analyses methods. Here we report on a relatively large sample of abstinent methamphetamine users at various stages of long-term abstinence. Methods Chronic methamphetamine users (n = 99), abstinent from the drug ranging from 12 to 621 days, and healthy controls (n = 86) received T1-weighted structural magnetic resonance imaging brain scans. Subcortical and cortical gray-matter volumes and cortical thickness were measured and the effects of group, duration of abstinence, duration of methamphetamine use and onset age of methamphetamine use were investigated using the Freesurfer software package. Results Methamphetamine users did not differ from controls in gray-matter volumes, except for a cluster in the right lateral occipital cortex where gray-matter volume was smaller, and for regions mainly in the bilateral superior frontal gyrui where thickness was greater. Duration of abstinence correlated positively with gray-matter volumes in whole brain, bilateral accumbens nuclei and insulae clusters, and right hippocampus; and with thickness in a right insula cluster. Duration of methamphetamine use correlated negatively with gray-matter volume and cortical thickness of a cluster in the right lingual and pericalcarine cortex. Conclusions Chronic methamphetamine use induces hard-to-recover cortical thickening in bilateral superior frontal gyri and recoverable volumetric reduction in right hippocampus, bilateral accumbens nuclei and bilateral cortical regions around insulae. These alternations might contribute to methamphetamine-induced neurocognitive disfunctions and reflect a regional specific response of the brain to methamphetamine.


2021 ◽  
Vol 10 (23) ◽  
pp. 5480
Author(s):  
Laura Vidal ◽  
Miguel A Ortega ◽  
Miguel Angel Alvarez-Mon ◽  
Melchor Álvarez-Mon ◽  
Guillermo Lahera

Eating disorders are relatively frequent psychiatric disorders that can produce serious consequences at the brain level. In an effort to clarify the neurobiological mechanisms of their pathogenesis, some studies have suggested the existence of modifications of the cortical architecture in eating disorders, but it is unknown whether the alterations described are a cause or consequence of eating disorders. The main objective of this systematic review is to collect the evidence available about the volumetric alterations of the cerebral cortex in eating disorders in adults and their apparent relationship with the pathogenesis of the disease. Initially, 91 articles were found by a search that included the terms anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder, gray matter, cortical thickness (CT), and brain volume. To pare down the articles, the following inclusion criteria were applied: (1) cortical thickness and/or gray matter volume (GMV) in patients with anorexia, bulimia nervosa, or binge-eating disorder was the main measure of the study; and (2) the sample was adult patients aged 18–65. The exclusion criteria were as follows: (1) articles that did not analyze cortical thickness or gray matter volume; (2) studies with patients with comorbidities; and (3) studies in patients who did not meet the DSM-IV/DSM-V criteria. In the first phase of selection, we proceeded to read the titles and abstracts as a first screen, thereby excluding 62 studies, followed by a complete critical reading of the 29 remaining articles. In this last phase, nine studies were excluded because they did not specify the eating disorder subtype, they included adolescents, or they did not measure GMV or CT. Finally, after the above systematic selection process, 20 articles were included in this review. Despite the methodological heterogeneity of the studies, there was some agreement between them. They showed an overall reduction in GMV in eating disorders, as well as alterations in certain regions of the cerebral cortex. Some of the most often mentioned cortical areas were the frontal, cingulate, and right orbitofrontal cortices, the precuneus, the right insula, and some temporoparietal gyri in cases of AN, with greater cortical involvement in frontotemporal and medial orbitofrontal regions in BN and binge eating disorder. Likewise, certain cortical regions, such as the left inferior frontal gyrus, the precuneus, the right superior motor area, the cingulate cortex, the insula, and the medial orbitofrontal sulcus, often remained altered after recovery from AN, making them potential cortical areas involved in the etiopathogenesis of AN. A reduction in GMV in specific areas of the CNS can inform us about the neurobiological mechanisms that underlie eating disorders as well as give us a better understanding of their possible consequences at the brain level.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Elouise A. Koops ◽  
Emile de Kleine ◽  
Pim van Dijk

AbstractThe impact of age-related hearing loss extends beyond the auditory pathway and impacts brain areas related to cognitive impairment and even dementia. The presence of tinnitus, a sensation of sound that frequently co-occurs with hearing loss, is additionally linked to cognitive decline. Interestingly, structural neuroimaging studies have reported that hearing loss may precede or modulate the onset of cognitive impairment. In this study, we aimed to disentangle the effects of age, hearing loss, and tinnitus on gray matter structure. In total, 39 participants with hearing loss and tinnitus, 21 with hearing loss but without tinnitus, and 39 controls were included in this voxel- and surface-based morphometry MRI study. Whole brain volume and surface thickness measures were compared between the groups. Age-related gray matter volume decline was observed in all groups. Several brain areas showed smaller gray matter volume and cortical surface thickness in hearing loss without tinnitus, relative to controls. This reduction was observed both within and outside of the auditory pathway. Interestingly, these reductions were not observed in participants with tinnitus, who had similar hearing loss and were of similar age. Since we have tools to improve hearing loss, hearing screening may aid in the battle against cognitive decline.


2021 ◽  
Vol 15 ◽  
Author(s):  
Mengzhe You ◽  
Xia Zhou ◽  
Wenwen Yin ◽  
Ke Wan ◽  
Wei Zhang ◽  
...  

The methylenetetrahydrofolate reductase (MTHFR) gene has been associated with Alzheimer’s disease (AD) pathogenesis. Amnestic mild cognitive impairment (aMCI) represents a prodromal stage of dementia and involves a high risk of progression into AD. Although the effects of the apolipoprotein E (APOE) gene on structural alterations in aMCI have been widely investigated, the effects of MTHFR C677T and interaction effects of MTHFR × APOE genotypes on gray matter atrophy in aMCI remain largely unknown. In the present study, 60 aMCI patients and 30 healthy controls were enrolled, and voxel-based morphometry analysis was performed to inspect the effects of diagnosis, different genotypes, and their interactions on gray matter atrophy. The results showed that aMCI patients had significant gray matter atrophy involving the bilateral hippocampus, the right parahippocampal gyrus, and the left superior temporal gyrus compared with healthy controls. Besides, a substantial reduction in gray matter volume was observed in the right hippocampus region in APOE ε4 carriers from the aMCI group, compared with APOE ε4 non-carriers. A significant interaction was found between diagnosis and MTHFR C677T genotype on the right precuneus in healthy controls and aMCI patients not carrying APOE ε4 allele. Our findings may provide new evidence substantiating the genetic effects of MTHFR C677T on brain structural alternation in patients with aMCI.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yoko Shigemoto ◽  
Daichi Sone ◽  
Miho Ota ◽  
Norihide Maikusa ◽  
Masayo Ogawa ◽  
...  

2019 ◽  
pp. 135910531986997 ◽  
Author(s):  
Huazhan Yin ◽  
Li Zhang ◽  
Dan Li ◽  
Lu Xiao ◽  
Mei Cheng

This study investigated the neuroanatomical basis of the association between depression/anxiety and sleep quality among 370 college students. The results showed that there was a significant correlation between sleep quality and depression/anxiety. Moreover, mediation results showed that the gray matter volume of the right insula mediated the relationship between depression/anxiety and sleep quality, which suggested that depression/anxiety may affect sleep quality through the right insula volume. These findings confirmed a strong link between sleep quality and depression/anxiety, while highlighting the volumetric variation in the right insula associated with emotional processing, which may play a critical role in improving sleep quality.


2020 ◽  
Author(s):  
Joshua M. Carlson ◽  
Lin Fang

AbstractIn a sample of highly anxious individuals, the relationship between gray matter volume brain morphology and attentional bias to threat was assessed. Participants performed a dot-probe task of attentional bias to threat and gray matter volume was acquired from whole brain structural T1-weighted MRI scans. The results replicate previous findings in unselected samples that elevated attentional bias to threat is linked to greater gray matter volume in the anterior cingulate cortex, middle frontal gyrus, and striatum. In addition, we provide novel evidence that elevated attentional bias to threat is associated with greater gray matter volume in the right posterior parietal cortex, cerebellum, and other distributed regions. Lastly, exploratory analyses provide initial evidence that distinct sub-regions of the right posterior parietal cortex may contribute to attentional bias in a sex-specific manner. Our results illuminate how differences in gray matter volume morphology relate to attentional bias to threat in anxious individuals. This knowledge could inform neurocognitive models of anxiety-related attentional bias to threat and targets of neuroplasticity in anxiety interventions such as attention bias modification.


SLEEP ◽  
2019 ◽  
Vol 42 (12) ◽  
Author(s):  
Ambra Stefani ◽  
Thomas Mitterling ◽  
Anna Heidbreder ◽  
Ruth Steiger ◽  
Christian Kremser ◽  
...  

Abstract Study Objectives Integrated information on brain microstructural integrity and iron storage and its impact on the morphometric profile is not available in restless legs syndrome (RLS). We applied multimodal magnetic resonance imaging (MRI) including diffusion tensor imaging, the transverse relaxation rate (R2*), a marker for iron storage, as well as gray and white matter volume measures to characterize RLS-related MRI signal distribution patterns and to analyze their associations with clinical parameters. Methods Eighty-seven patients with RLS (mean age 51, range 20–72 years; disease duration, mean 13 years, range 1–46 years, of those untreated n = 30) and 87 healthy control subjects, individually matched for age and gender, were investigated with multimodal 3T MRI. Results Volume of the white matter compartment adjacent to the post- and precentral cortex and fractional anisotropy (FA) of the frontopontine tract were both significantly reduced in RLS compared to healthy controls, and these alterations were associated with disease duration (r = 0.25, p = 0.025 and r = 0.23, p = 0.037, respectively). Corresponding gray matter volume increases of the right primary motor cortex in RLS (p < 0.001) were negatively correlated with the right FA signal of the frontopontine tract (r = −0.22; p < 0.05). Iron content evaluated with R2* was reduced in the putamen as well as in temporal and occipital compartments of the RLS cohort compared to the control group (p < 0.01). Conclusions Multimodal MRI identified progressing white matter decline of key somatosensory circuits that may underlie the perception of sensory leg discomfort. Increases of gray matter volume of the premotor cortex are likely to be a consequence of functional neuronal reorganization.


2012 ◽  
Vol 8 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Mei-Kei Leung ◽  
Chetwyn C. H. Chan ◽  
Jing Yin ◽  
Chack-Fan Lee ◽  
Kwok-Fai So ◽  
...  

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