Gray Matter Volume In Putamen Research Articles

Are there any differences at gray matter sites between severe obstructive sleep apnea patients and healthy controls?

ObjectivesObstructive sleep apnea (OSA) is a disease that may cause many medical conditions. Neurocognitive disorders may be triggered by OSA. In recent studies, selectively decreased gray matter tissue was observed in patients with OSA. We aimed to determine if there was a substantial difference in patients with extreme OSA by comparing the microstructural changes in different gray matter sub-areas with healthy controls using diffusion-weighted imaging methods. MethodsWe studied 15 diagnosed severe OSA subjects before any treatment and 32 healthy control subjects. High resolution Magnetic Resonance Imaging (MRI) T1 and T2-weighted scans were visually examined to assess any major brain lesions. ResultsThere were no statistically significant differences of age and gender between the groups.The left and right globus pallidus, putamen and thalamus values did not differ significantly between OSA and control subjects. Right putamen values was negatively correlated with Apnea Hypopnea Index (AHI), supine AHI and non-REM AHI in OSA subjects, but no correlations appeared with left putamen values. The other gray matter parameters did not show any correlations with PSG parameters. AHI, Supine AHI, Non-Supine AHI, REM and NON-REM AHI values was not show any correlation with Right and Left Putamen volume sizes. ConclusionsWe made a morphological comparison of various gray matter areas of OSA patients and healthy volunteers in our study. We observed a significant decrease in right putamen gray matter volumes in patients with higher AHI values. Decreased cognitive functions are found in patients with OSA. In order to demonstrate this cognitive loss in patients with morphologically there is a need for further prospective studies with larger sample sizes.

A significant, functional and replicable risk KTN1 variant block for schizophrenia

Cortical and subcortical structural alteration has been extensively reported in schizophrenia, including the unusual expansion of gray matter volumes (GMVs) of basal ganglia (BG), especially putamen. Previous genome-wide association studies pinpointed kinectin 1 gene (KTN1) as the most significant gene regulating the GMV of putamen. In this study, the role of KTN1 variants in risk and pathogenesis of schizophrenia was explored. A dense set of SNPs (n = 849) covering entire KTN1 was analyzed in three independent European- or African-American samples (n = 6704) and one mixed European and Asian Psychiatric Genomics Consortium sample (n = 56,418 cases vs. 78,818 controls), to identify replicable SNP-schizophrenia associations. The regulatory effects of schizophrenia-associated variants on the KTN1 mRNA expression in 16 cortical or subcortical regions in two European cohorts (n = 138 and 210, respectively), the total intracranial volume (ICV) in 46 European cohorts (n = 18,713), the GMVs of seven subcortical structures in 50 European cohorts (n = 38,258), and the surface areas (SA) and thickness (TH) of whole cortex and 34 cortical regions in 50 European cohorts (n = 33,992) and eight non-European cohorts (n = 2944) were carefully explored. We found that across entire KTN1, only 26 SNPs within the same block (r2 > 0.85) were associated with schizophrenia across ≥ 2 independent samples (7.5 × 10–5 ≤ p ≤ 0.048). The schizophrenia-risk alleles, which increased significantly risk for schizophrenia in Europeans (q < 0.05), were all minor alleles (f < 0.5), consistently increased (1) the KTN1 mRNA expression in 12 brain regions significantly (5.9 × 10–12 ≤ p ≤ 0.050; q < 0.05), (2) the ICV significantly (6.1 × 10–4 ≤ p ≤ 0.008; q < 0.05), (3) the SA of whole (9.6 × 10–3 ≤ p ≤ 0.047) and two regional cortices potentially (2.5 × 10–3 ≤ p ≤ 0.042; q > 0.05), and (4) the TH of eight regional cortices potentially (0.006 ≤ p ≤ 0.050; q > 0.05), and consistently decreased (1) the BG GMVs significantly (1.8 × 10–19 ≤ p ≤ 0.050; q < 0.05), especially putamen GMV (1.8 × 10–19 ≤ p ≤ 1.0 × 10–4; q < 0.05, (2) the SA of four regional cortices potentially (0.010 ≤ p ≤ 0.048), and (3) the TH of four regional cortices potentially (0.015 ≤ p ≤ 0.049) in Europeans. We concluded that we identified a significant, functional, and robust risk variant block covering entire KTN1 that might play a critical role in the risk and pathogenesis of schizophrenia.

NR4A1 Methylation Associated Multimodal Neuroimaging Patterns Impaired in Temporal Lobe Epilepsy.

DNA hypermethylation has been widely observed in temporal lobe epilepsy (TLE), in which NR4A1 knockdown has been reported to be able to alleviate seizure severity in mouse model, while the underlying methylation-imaging pathway modulated by aberrant methylation levels of NR4A1 remains to be clarified in patients with TLE. Here, using multi-site canonical correlation analysis with reference, methylation levels of NR4A1 in blood were used as priori to guide fusion of three MRI features: functional connectivity (FC), fractional anisotropy (FA), and gray matter volume (GMV) for 56 TLE patients and 65 healthy controls. Post-hoc correlations were further evaluated between the identified NR4A1-associated brain components and disease onset. Results suggested that higher NR4A1 methylation levels in TLE were related with impaired temporal-cerebellar and occipital-cerebellar FC strength, lower FA in cingulum (hippocampus), and reduced GMV in putamen, temporal pole, and cerebellum. Moreover, findings were also replicated well in both patient subsets with either right TLE or left TLE only. Particularly, right TLE patients showed poorer cognitive abilities and more severe brain impairment than left TLE patients, especially more reduced GMV in thalamus. In summary, this work revealed a potential imaging-methylation pathway modulated by higher NR4A1 methylation in TLE via data mining, which may impact the above-mentioned multimodal brain circuits and was also associated with earlier disease onset and more cognitive deficits.

Psychopathy Moderates the Relationship between Orbitofrontal and Striatal Alterations and Violence: The Investigation of Individuals Accused of Homicide.

Brain structural abnormalities in the orbitofrontal cortex (OFC) and striatum (caudate and putamen) have been observed in violent individuals. However, a uni-modal neuroimaging perspective has been used and prior findings have been mixed. The present study takes the multimodal structural brain imaging approaches to investigate the differential gray matter volumes (GMV) and cortical thickness (CTh) in the OFC and striatum between violent (accused of homicide) and non-violent (not accused of any violent crimes) individuals with different levels of psychopathic traits (interpersonal and unemotional qualities, factor 1 psychopathy and the expressions of antisocial disposition and impulsivity, factor 2 psychopathy). Structural Magnetic Resonance Imaging data, psychopathy and demographic information were assessed in sixty seven non-violent or violent adults. The results showed that the relationship between violence and the GMV in the right lateral OFC varied across different levels of the factor 1 psychopathy. At the subcortical level, the psychopathy level (the factor 1 psychopathy) moderated the positive relationship of violence with both left and right putamen GMV as well as left caudate GMV. Although the CTh findings were not significant, overall findings suggested that psychopathic traits moderated the relationship between violence and the brain structural morphology in the OFC and striatum. In conclusion, psychopathy takes upon a significant role in moderating violent behavior which gives insight to design and implement prevention measures targeting violent acts, thereby possibly mitigating their occurrence within the society.

Structural Gray Matter Alterations in Chronic Migraine: Implications for a Progressive Disease?

To identify possible gray matter alterations in patients with chronic migraine using voxel-based morphometry (VBM). VBM studies demonstrate structural alterations of gray matter (GM) in episodic migraine (EM) patients. Some of these alterations correlate with disease duration and headache frequency. We assessed GM alterations in chronic migraine (CM) and EM to evaluate the concept of migraine as a progressive disorder of the brain. Individually age and sex-matched subjects with CM or EM (both without aura) and healthy controls (n = 21 per group) underwent magnetic resonance imaging-based VBM. We found an increase of GM volume (GMV) in amygdala and putamen, in CM compared to controls. GMV of EM compared to controls did not differ statistically significantly. Headache frequency in all migraineurs (EM and CM) correlated positively with GMV in putamen, frontal and temporal gyrus and negatively in left cuneus. CM is associated with structural changes in brain regions involved in pain processing but also in affective and cognitive aspects of pain. Some GM alterations are correlated with headache frequency assessed in EM and CM. The findings support the assumption that chronic pain alters brain plasticity. GMV increase may reflect a remodeling of the central nervous system due to repetitive headache attacks leading to chronic sensitization and a continuous ictal-like state of the brain in chronic migraineurs.

Morphological correlates to cognitive dysfunction in schizophrenia as studied with Bayesian regression

BackgroundRelationships between cognitive deficits and brain morphological changes observed in schizophrenia are alternately explained by less gray matter in the brain cerebral cortex, by alterations in neural circuitry involving the basal ganglia, and by alteration in cerebellar structures and related neural circuitry. This work explored a model encompassing all of these possibilities to identify the strongest morphological relationships to cognitive skill in schizophrenia.MethodsSeventy-one patients with schizophrenia and sixty-five healthy control subjects were characterized by neuropsychological tests covering six functional domains. Measures of sixteen brain morphological structures were taken using semi-automatic and fully manual tracing of MRI images, with the full set of measures completed on thirty of the patients and twenty controls. Group differences were calculated. A Bayesian decision-theoretic method identified those morphological features, which best explained neuropsychological test scores in the context of a multivariate response linear model with interactions.ResultsPatients performed significantly worse on all neuropsychological tests except some regarding executive function. The most prominent morphological observations were enlarged ventricles, reduced posterior superior vermis gray matter volumes, and increased putamen gray matter volumes in the patients.The Bayesian method associated putamen volumes with verbal learning, vigilance, and (to a lesser extent) executive function, while caudate volumes were associated with working memory. Vermis regions were associated with vigilance, executive function, and, less strongly, visuo-motor speed. Ventricular volume was strongly associated with visuo-motor speed, vocabulary, and executive function. Those neuropsychological tests, which were strongly associated to ventricular volume, showed only weak association to diagnosis, possibly because ventricular volume was regarded a proxy for diagnosis. Diagnosis was strongly associated with the other neuropsychological tests, implying that the morphological associations for these tasks reflected morphological effects and not merely group volumetric differences. Interaction effects were rarely associated, indicating that volumetric relationships to neuropsychological performance were similar for both patients and controls.ConclusionThe association of subcortical and cerebellar structures to verbal learning, vigilance, and working memory supports the importance of neural connectivity to these functions. The finding that a morphological indicator of diagnosis (ventricular volume) provided more explanatory power than diagnosis itself for visuo-motor speed, vocabulary, and executive function suggests that volumetric abnormalities in the disease are more important for cognition than non-morphological features.

Anatomical MRI study of basal ganglia in bipolar disorder patients

This study examined possible anatomical abnormalities in basal ganglia structures in bipolar disorder patients. Caudate and putamen gray matter volumes, and globus pallidus total volume were measured with magnetic resonance imaging (MRI) in 22 DSM-IV bipolar patients (age±S.D.=36±10 years; eight drug-free and 14 lithium monotherapy patients) and 22 matched healthy control subjects (age±S.D.=38±10 years). No significant differences were found between bipolar patients and healthy control subjects for any of the basal ganglia measures ( t-tests, P>0.05). Age was inversely correlated with left putamen volumes in patients ( R=−0.44, P=0.04), but not in healthy control subjects ( R=−0.33, P=0.14). Older patients (>36 years old) had a significantly larger left globus pallidus than younger ones (≤36 years old) (ANOVA, P=0.01). In a multiple regression analysis, after entering age as independent variable, the length of illness predicted smaller left putamen volumes, explaining 10.4% of the variance ( F=4.07, d.f.=2, P=0.03). No significant effects of episode type, number of prior episodes, or gender were found in any basal ganglia measurements (ANOVA, P>0.05). In conclusion, our findings indicate that the basal ganglia may be anatomically preserved in bipolar patients. This is in contrast to available findings for unipolar disorder. However, our findings also suggest that age and length of illness may have significant effects on basal ganglia structures in bipolar patients, which may be more pronounced among bipolar I patients, and of relevance for the pathophysiology of the disorder.

342. Anatomical MRI study of basal ganglia in bipolar disorder patients

Findings from MRI studies suggested basal ganglia abnormalities in unipolar depression. In bipolar disorder, the available results have been mostly inconclusive. This study examined further the possibility of anatomical basal ganglia abnormalities in bipolar subjects. 7 DSM-IV drug-free bipolar patients (mean ± S.D. age = 37.4 ± 6.3), 15 lithium-treated bipolar patients (mean ± S.D. age = 34.9 ± 9.4) and 16 healthy controls (mean ± S.D. age = 36.0 ± 9.3) were studied. A 1.5T GE Signa magnet with Signa 5.4.3 software (General Electrics, Inc. Milwaukee, WI) was used. 3D gradient echo imaging (SPGR) was used (TR = 25 ms, TE = 5 ms, nutation angle = 40°, FOV = 24 cm, slice thickness = 1.5 mm, NEX = 1, matrix size = 256 × 192). Image analysis was conducted blindly on the semi-automated software Scion Image (Scion Corporation, Inc., Frederick, MD). No significant differences were found among groups for caudate and putamen gray matter volumes (ANOVA, p > 0.05). However, significant inverse correlation with age was found for right caudate, and right and left putamen gray matter volumes in patients (r = −0.488, p = 0.021; r = −0.453, p = 0.034; r = −0.546, p = 0.009), but not in controls. A significant inverse correlation between length of illness and left putamen gray matter volumes was also found in patients (Spearman Coefficient = −0.427, p = 0.048). MRI anatomical abnormalities in basal ganglia may be more characteristic of unipolar than bipolar disorder. However, our results suggest that age and length of illness could be relevant factors leading to increased loss of gray matter volume in basal ganglia structures, and part of the brain mechanisms that may be implicated in the pathophysiology of bipolar disorder.