Introduction
Although mild traumatic brain injury (mTBI) comprises 80% of all TBI, the morphological examination of the orbitofrontal cortex (OFC) in relation to clinical symptoms such as aggression, ...anxiety and depression in a strictly mTBI sample has never before been performed.
Objectives
The primary objective of the study was to determine if mTBI patients would show morphological differences in the OFC and if the morphology of this region would relate to clinical symptoms.
Methods
Using structural images acquired in a 3T MRI machine, the cortical thickness and cortical volume (corrected for total brain volume) of the OFC was collected for healthy control (N = 27) subjects and chronic mTBI (N = 55) patients at least one year post injury. Also, during clinical interviews, measures quantifying the severity of clinical symptoms, including aggression, anxiety, and depression, were collected.
Results
MTBI subjects displayed increased aggression, anxiety, and depression, and anxiety and depression measures showed a relationship with the number of mTBI in which the subject lost consciousness. The cortical thickness of the right lateral OFC displayed evidence of thinning in the mTBI group; however, after correction for multiple comparisons, this difference was no longer significant. Clinical measures were not significantly related with OFC morphometry.
Conclusion
This study found increased aggression, anxiety, and depression, in the mTBI group as well as evidence of cortical thinning in the right lateral OFC. The association between clinical symptoms and the number of mTBI with loss of consciousness suggests the number and severity of mTBI may influence clinical symptoms long after injury. Future studies examining other brain regions involved in the production and regulation of affective processes and inclusion of subjects with well‐characterized mood disorders could further elucidate the relationship between mTBI, brain morphology, and clinical symptoms.
Mild Traumatic Brain Injury (mTBI) comprises upwards of 80% of TBI, but to date, the neurobiological underpinnings of aggression in this population have not been morphologically explored.Compared to a health control group (N = 27), a mTBI group (N = 55) exhibited a significant decrease in the cortical thickness of the right LOFC. Additionally, the mTBI group displayed increased aggression on the Buss Perry Aggression Questionnaire, which negatively correlated with lateral OFC (LOFC) cortical thickness.
We determined risk factors that discriminate between suicide attempt (SA) adolescents and suicidal ideation only (SI only) adolescents using data from the 2010 Korea Youth Risk Behavior Web‐based ...Survey (12–19 years; N = 73,238). In males, heavy alcohol use, drug use, and high perceived sadness/hopelessness showed significant effects on the presence of SA versus the presence of SI only. In females, along with these variables, low academic achievement, poor perceived health status, high perceived stress, and unhealthy coping strategy were also significantly related to the presence of SA versus SI only. Therefore, clinical interventions targeting adolescents' psychological distress are warranted to prevent suicide.
•Veterans with a suicide attempt had reduced left rACC WMV compared to ideators.•Reduced left rACC WMV was correlated with nonplanning impulsivity for Attempters.•Veteran ideators and attempters did ...not differ on measures of impulsivity.•Regional ACC WMV differences were associated with impulsivity and suicide attempts.
Suicide is one of the leading causes of death for military personnel and Veterans. Neuroimaging studies have revealed abnormalities in white matter tracts and brain connectivity in suicide behavior (SB); however, reports of alterations in white matter volume and its association with related behaviors are limited. The current study examined the relationship between cingulate white matter volume (WMV), impulsivity, and SB in Veterans.
Fifty-two Veterans, ages 18 to 65, underwent magnetic resonance imaging on a 3T Siemens Verio scanner. Morphometric analysis of brain images was performed to evaluate differences in WMV in cingulate regions of interest. Participants completed the Columbia Suicide Severity Rating Scale to assess lifetime suicide behavior and the Barratt Impulsivity Scale (BIS) and the Continuous Performance Test (CPT) to assess impulsivity.
Twenty-nine Veterans had a history of suicidal ideation (SI) and 23 had a history of suicide attempts (SA). Controlling for age, sex, handedness and total white matter volume, reduced WMV was observed in the left rostral anterior cingulate cortex (rACC) in Veterans with SA relative to Veterans with SI, p = .008. Additionally, non-planning on the BIS was negatively correlated with left rACC WMV for Veterans with a history of SA, p = .04. Other subregions of the ACC WMV were negatively correlated with planning and attention impulsivity (BIS) and omission and commission errors (CPT) for attempters.
Reduction in rACC WMV in Veterans with SA was negatively correlated with nonplanning measures. These findings are consistent with ACC involvement in inhibitory processes and build on evidence that SB is associated with neurobiological abnormalities and suggest that white matter changes may be related to actual attempts.
The effect of antipsychotic medication on neurocognitive function remains controversial, especially since most previous work has compared the effects of novel antipsychotic medications with those of ...high doses of conventional medications. This study compares the neurocognitive effects of olanzapine and low doses of haloperidol in patients with first-episode psychosis.
Patients with a first episode of schizophrenia, schizoaffective disorder, or schizophreniform disorder (N=167) were randomly assigned to double-blind treatment with olanzapine (mean modal dose= 9.63 mg/day) or haloperidol (mean modal dose=4.60 mg/day) for the 12-week acute phase of a 2-year study. The patients were assessed with a battery of neurocognitive tests at baseline and 12 weeks after beginning treatment.
An unweighted neurocognitive composite score, composed of measures of verbal fluency, motor functions, working memory, verbal memory, and vigilance, improved significantly with both haloperidol and olanzapine treatment (effect sizes of 0.20 and 0.36, respectively, no significant difference between groups). A weighted composite score developed from a principal-component analysis of the same measures improved to a significantly greater degree with olanzapine, compared with haloperidol. Anticholinergic use, extrapyramidal symptoms, and estimated IQ had little effect on the statistical differentiation of the medications, although duration of illness had a modest effect. The correlations of cognitive improvement with changes in clinical characteristics and with side effects of treatment were significant for patients who received haloperidol but not for patients who received olanzapine.
Olanzapine has a beneficial effect on neurocognitive function in patients with a first episode of psychosis. However, in a comparison of the effects of olanzapine and low doses of haloperidol, the difference in benefit is small.
Abstract Background Based on growing evidence of the crucial role of the cerebellum in emotional regulation, we sought to identify cerebellar structural deficits in a large sample of patients with ...bipolar disorder (BD). Methods Cerebellar gray matter density was examined in 49 BD patients (24 medication-naive and 25 medication-treated) and 50 carefully matched healthy individuals, using voxel-based morphometry with a high-resolution spatially unbiased atlas template of the human cerebellum. This recently developed methodology is specifically optimized for the assessment of cerebellar structures. We further explored whether antimanic treatment could attenuate cerebellar structural deficits. Results BD patients showed a greater reduction in gray matter density of the posterior cerebellar regions, including the bilateral vermi and the right crus relative to healthy individuals (corrected p <.05). A stepwise linear reduction in gray matter density was observed in bilateral vermal regions between healthy individuals, medication-treated, and medication-naive BD patients. Furthermore, positive correlations of longer duration of illness with bilateral vermal gray matter deficits were observed only in medication-naive BD patients, but not in patients with medication history. Limitations This study adopted a cross-sectional design. The automatic intensity-normalization method for the measurement of cerebellar gray matter density may have a limitation in providing detailed anatomical information at a cerebellar folia level. Conclusions The current findings suggest that BD-related deficits in the posterior cerebellar regions, which appear to progress over the course of illness, could potentially be ameliorated by proper treatment with mood stabilizers.
Converging evidence from neuroimaging and neuropsychological studies indicates that heavy marijuana use is associated with cingulate dysfunction. However, there has been limited human data ...documenting in vivo biochemical brain changes after chronic marijuana exposure. Previous proton magnetic resonance spectroscopy studies have demonstrated reduced basal ganglia glutamate and dorsolateral prefrontal cortex N-acetyl aspartate levels in adult chronic marijuana users. Similar studies have not been reported in adolescent populations. The present study used proton magnetic resonance spectroscopy to determine whether reductions in glutamate, N-acetyl aspartate and/or other proton metabolite concentrations would be found in the anterior cingulate cortex (ACC) of adolescent marijuana users compared with non-using controls. Adolescent marijuana users (N=17; average age 17.8years) and similarly aged healthy control subjects (N=17; average age 16.2years) were scanned using a Siemens 3T Trio MRI system. Proton magnetic resonance spectroscopy data were acquired from a 22.5mL voxel positioned bilaterally within the ACC. Spectra were fitted using commercial software and all metabolite integrals were normalized to the scaled unsuppressed water integral. Analysis of variance and analysis of covariance were performed to compare between-group metabolite levels. The marijuana-using cohort showed statistically significant reductions in anterior cingulate glutamate (−15%, p<0.01), N-acetyl aspartate (−13%, p=0.02), total creatine (−10%, p<0.01) and myo-inositol (−10%, p=0.03). Within-voxel tissue-type segmentation did not reveal any significant differences in gray/white matter or cerebrospinal fluid content between the two groups. The reduced glutamate and N-acetyl aspartate levels in the adolescent marijuana-using cohort are consistent with precedent human 1H MRS data, and likely reflect an alteration of anterior cingulate glutamatergic neurotransmission and neuronal integrity within these individuals. The reduced total creatine and myo-inositol levels observed in these subjects might infer altered ACC energetic status and glial metabolism, respectively. These results expand on previous functional MRI data reporting altered cingulate function in individuals with marijuana-abuse.
► MRS identifies neurochemical alterations in adolescent chronic marijuana smokers. ► ACC glutamate is significantly reduced in adolescent chronic marijuana smokers. ► ACC NAA is significantly reduced in adolescent chronic marijuana smokers.
Cytidine-5′-diphosphate choline (CDP-choline) has been suggested to exert neuroprotective and neuroreparative effects and may be beneficial for patients with stimulant dependence. This randomized, ...double-blind, placebo-controlled study in methamphetamine (MA) dependence investigated effects of CDP-choline on the brain structures and their associations with craving and MA use.
MA users (n = 44) were randomized to receive 2 g/day of CDP-choline (n = 22) or placebo (n = 22) for 8 weeks. Patients underwent brain magnetic resonance imaging (MRI) at baseline and 8-week follow-up. Healthy individuals (n = 27) were also examined using brain MRI at the same interval. Voxel-based morphometry analysis was conducted to examine changes in gray matter (GM) volumes and their associations with craving and MA use.
Craving for MA was significantly reduced after the 8 week-treatment with CDP-choline (p = 0.01), but not with the placebo treatment (p = 0.10). There was no significant difference in the total number of MA-negative urine samples between the two groups (p = 0.19). With CDP-choline treatment, GM volumes in the left middle frontal gyrus (p = 0.001), right hippocampus (p = 0.009), and left precuneus (p = 0.001) were significantly increased compared to the placebo and control groups. Increased GM volumes in the left middle frontal gyrus with CDP-choline treatment were associated with reduced craving for MA (Spearman's ρ = −0.56, p = 0.03). In addition, the right hippocampal volume increases were positively associated with the total number of MA-negative urine results in the CDP-choline group (Spearman's ρ = 0.67, p = 0.006).
Our findings suggest that CDP-choline may increase GM volumes of MA-dependent patients, which may be related to decreases in MA use and craving.
Many neuropsychological studies have documented deficits in working memory among recent heavy cannabis users. However, little is known about the effects of cannabis on brain activity.
We assessed ...brain function among recent heavy cannabis users while they performed a working memory task.
Functional magnetic resonance imaging was used to examine brain activity in 12 long-term heavy cannabis users, 6-36 h after last use, and in 10 control subjects while they performed a spatial working memory task. Regional brain activation was analyzed and compared using statistical parametric mapping techniques.
Compared with controls, cannabis users exhibited increased activation of brain regions typically used for spatial working memory tasks (such as prefrontal cortex and anterior cingulate). Users also recruited additional regions not typically used for spatial working memory (such as regions in the basal ganglia). These findings remained essentially unchanged when re-analyzed using subjects' ages as a covariate. Brain activation showed little or no significant correlation with subjects' years of education, verbal IQ, lifetime episodes of cannabis use, or urinary cannabinoid levels at the time of scanning.
Recent cannabis users displayed greater and more widespread brain activation than normal subjects when attempting to perform a spatial working memory task. This observation suggests that recent cannabis users may experience subtle neurophysiological deficits, and that they compensate for these deficits by "working harder"-calling upon additional brain regions to meet the demands of the task.
Objective:
It has been hypothesized that disturbances in affect may represent distinct etiologic factors for bipolar affective disorder. The neural mechanisms mediating affective processes and their ...relationship to brain development and the pathophysiology of bipolar affective disorder remain to be clarified. Recent advances in neuroimaging techniques have made possible the non‐invasive examination of specific brain regions during cortical challenge paradigms. This study reports findings based on fMRI data acquired during fearful and happy affect recognition paradigms in patients with bipolar affective disorder and in healthy adult subjects.
Methods: Prior to the scan, subjects were instructed to view the stimuli and to identify the type of facial expression presented. Echo planar scanning was performed on a 1.5 Tesla scanner which had been retrofitted with a whole body echo planar coil, using a head coil.
Results: The data indicate that in adult subjects with bipolar affective disorder, there is a reduction in dorsolateral prefrontal cortex activation and an increase in amygdalar activation in response to fearful facial affect. In a healthy comparison group, signal intensity changes were not found in these regions. In addition, although the patients with bipolar affective disorder completed the task demands, they demonstrated an impaired ability to correctly identify fearful facial affect but not the happy facial affect displayed.
Conclusion: These findings are consistent with the hypothesis that in some patients with bipolar affective disorder, there may be a reduction of frontal cortical function which may be associated with affective as well as attentional processing deficits.
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