Tobacco smoking and MRI/MRS brain abnormalities compared to nonsmokers

Medial prefrontal cortex neurotransmitter abnormalities in posttraumatic stress disorder with and without comorbidity to major depression

Posttraumatic stress disorder (PTSD) is a chronic psychiatric condition that follows exposure to a traumatic stressor. Though previous in vivo proton (1H) MRS) research conducted at 4 T or lower has identified alterations in glutamate metabolism associated with PTSD predisposition and/or progression, no prior investigations have been conducted at higher field strength. In addition, earlier studies have not extensively addressed the impact of psychiatric comorbidities such as major depressive disorder (MDD) on PTSD-associated 1H-MRS-visible brain metabolite abnormalities. Here we employ 7 T 1H MRS to examine concentrations of glutamate, glutamine, GABA, and glutathione in the medial prefrontal cortex (mPFC) of PTSD patients with MDD (PTSD+MDD+; N = 6) or without MDD (PTSD+MDD-; N = 5), as well as trauma-unmatched controls without PTSD but with MDD (PTSD-MDD+; N = 9) or without MDD (PTSD-MDD-; N = 18). Participants with PTSD demonstrated decreased ratios of GABA to glutamine relative to healthy PTSD-MDD- controls but no single-metabolite abnormalities. When comorbid MDD was considered, however, MDD but not PTSD diagnosis was significantly associated with increased mPFC glutamine concentration and decreased glutamate:glutamine ratio. In addition, all participants with PTSD and/or MDD collectively demonstrated decreased glutathione relative to healthy PTSD-MDD- controls. Despite limited findings in single metabolites, patterns of abnormality in prefrontal metabolite concentrations among individuals with PTSD and/or MDD enabled supervised classification to separate them from healthy controls with 80+% sensitivity and specificity, with glutathione, glutamine, and myoinositol consistently among the most informative metabolites for this classification. Our findings indicate that MDD can be an important factor in mPFC glutamate metabolism abnormalities observed using 1H MRS in cohorts with PTSD.

Proton Magnetic Resonance Spectroscopy in Post-Traumatic Stress Disorder-Updated Systematic Review and Meta-Analysis

A stressor-related disorder wherein traumatic experience precipitates protracted disruptions to mood and cognition, post-traumatic stress disorder (PTSD) is associated with wide-ranging abnormalities across the body. While various methods have investigated these deviations, only proton magnetic resonance spectroscopy (¹H MRS) enables noninvasive measurement of small-molecule metabolites in the living human. ¹H MRS has correspondingly been employed to test hypotheses about the composition and function of multiple brain regions putatively involved in PTSD. Here we systematically review methodological considerations and reported findings, both positive and negative, of the current ¹H-MRS literature in PTSD (N = 32 studies) to communicate the brain regional metabolite alterations heretofore observed, providing random-effects model meta-analyses for those most extensively studied. Our review suggests significant PTSD-associated decreases in N-acetyl aspartate in bilateral hippocampus and anterior cingulate cortex with less evident effect in other metabolites and regions. Model heterogeneities diverged widely by analysis (I² < 0.01% to 90.1%) and suggested regional dependence on quantification reference (creatine or otherwise). While observed variabilities in methods and reported findings suggest that ¹H-MRS explorations of PTSD could benefit from methodological standardization, informing this standardization by quantitative assessment of the existing literature is currently hampered by its small size and limited scope.

Smoking related attention alteration in chronic obstructive pulmonary disease-smoking comorbidity

Background

Chronic obstructive pulmonary disease (COPD) is a respiratory disease that causes a wide range of cognitive impairments. Although COPD-Smoking comorbidity is common, the relationship between smoking and cognitive function in COPD-Smoking comorbidity remains unclear. This study aimed to investigate the effect of smoking on cognitive function like attention in COPD-Smoking patients.

Methods

In this study, we used the Montreal Cognitive Assessment (MoCA) scale and resting-state functional magnetic resonance imaging (fMRI) to explore the effect of smoking on attention in patients with COPD.

Results

Behavioral analysis revealed that among patients with COPD the smokers had a shorter course of COPD and showed a worse attention performance than the non-smokers. Resting-state fMRI analysis revealed that among patients with COPD smokers showed lower regional homogeneity (ReHo) value of the fusiform gyrus than non-smokers. Importantly, the ReHo of the fusiform gyrus is positively associated with attention and mediates the effect of smoking on attention in COPD.

Conclusions

In summary, our study provides behavioral and neurobiological evidence supporting the positive effect of smoking on attention in COPD. This may be helpful for understanding and treating COPD and even other diseases comorbid with smoking.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01964-6.

Smoking history and adherence to cancer-related recommendations in a primary care setting

Public health prevention efforts have led to overall reductions in mortality from screening-preventable cancers. We explored cancer screening behaviors of smokers, former smokers, and nonsmokers among patients of large primary care practices to discover the relationship between smoking status and previous adherence to the United States Preventive Services Task Force breast, cervical, and colorectal cancer screening recommendations. Our descriptive study of electronic medical record data included 6,029 established primary care patients. Multi-predictor log-binomial regression models yielded prevalence ratios (PRs) and 95% confidence intervals (CIs) to determine associations between smoking status and the likelihood of nonadherence. All models were adjusted for race/ethnicity, age, insurance, primary care specialty, number of comorbidities, and sex. Smoking history was obtained from all participants in January 2020. Current smokers accounted for 4.8%, while 22.7% were former smokers, and 72.5% were never smokers. Current smokers (compared to never smokers) were 63% more likely to be mammogram nonadherent (PR: 1.63, 95% CI: 1.31 to 2.02), 26% more likely to be Pap smear nonadherent (PR: 1.26, 95% CI: 1.04 to 1.53), and 39% more likely to be colonoscopy nonadherent (PR: 1.39, 95% CI: 1.16 to 1.66). Current smokers and former Powered by Editorial Manager and ProduXion Manager from Aries Systems Corporation smokers had on average 2.9 comorbidities while never smokers had on average 2.1 comorbidities. Our findings showed that current smokers experienced significantly lower rates of cancer screening compared to never smokers. Further research is needed to investigate and identify best practices for increasing cancer screening uptake in this population.

Cerebrovascular and Neurological Dysfunction under the Threat of COVID-19: Is There a Comorbid Role for Smoking and Vaping?

The recently discovered novel coronavirus, SARS-CoV-2 (COVID-19 virus), has brought the whole world to standstill with critical challenges, affecting both health and economic sectors worldwide. Although initially, this pandemic was associated with causing severe pulmonary and respiratory disorders, recent case studies reported the association of cerebrovascular-neurological dysfunction in COVID-19 patients, which is also life-threatening. Several SARS-CoV-2 positive case studies have been reported where there are mild or no symptoms of this virus. However, a selection of patients are suffering from large artery ischemic strokes. Although the pathophysiology of the SARS-CoV-2 virus affecting the cerebrovascular system has not been elucidated yet, researchers have identified several pathogenic mechanisms, including a role for the ACE2 receptor. Therefore, it is extremely crucial to identify the risk factors related to the progression and adverse outcome of cerebrovascular-neurological dysfunction in COVID-19 patients. Since many articles have reported the effect of smoking (tobacco and cannabis) and vaping in cerebrovascular and neurological systems, and considering that smokers are more prone to viral and bacterial infection compared to non-smokers, it is high time to explore the probable correlation of smoking in COVID-19 patients. Herein, we have reviewed the possible role of smoking and vaping on cerebrovascular and neurological dysfunction in COVID-19 patients, along with potential pathogenic mechanisms associated with it.

Influenza vaccination reduces dementia in patients with chronic obstructive pulmonary disease: a nationwide cohort study

This study aimed to explore the protective potential of influenza vaccination against occurrence of dementia in patients with chronic obstructive pulmonary disease (COPD), who are expected to be more vulnerable to influenza infection. This nationwide retrospective cohort study enrolled patients with COPD (aged ≥60 years) from 1 January 2001 to 31 December 2012 by using the Taiwan National Health Insurance Research Database. By applying time-dependent Cox proportional hazard model, we used multivariate analysis to calculate the adjusted HR (aHR) with 95% CI of dementia in relation to influenza vaccination among patients with COPD. Besides, patients were partitioned into four groups according to the vaccination number (unvaccinated, 1, 2-3 and ≥4 total vaccinations) to investigate the dose-response effect of vaccinations on the dementia incidence. This cohort study included 19 848 patients with COPD, and 45% of them received influenza vaccination. The aHR of dementia was 0.68 (95% CI: 0.62 to 0.74, p<0.001) comparing vaccinated patients with unvaccinated ones. Furthermore, there was a trend of dementia risk reduction with the vaccination number. For patients who received 2-3 vaccinations, the aHR was 0.81 (95% CI: 0.73 to 0.90), and for those received 4 vaccinations, the aHR was 0.44 (95% CI: 0.40 to 0.50), with p for trend <0.001. In conclusion, annual influenza vaccination can reduce the risk of dementia in patient with COPD in a dose-dependent manner.

Neurochemical sex differences in adult ADHD patients: an MRS study

OBJECTIVE

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder. Relevant sex differences in symptomatology are discussed. This study compared brain neurometabolism in the anterior cingulate cortex (ACC) and left cerebellar hemisphere in age- and IQ-matched adult male (mADHD) and female (fADHD) ADHD patients.

METHODS

We studied 48 (ACC) and 42 (cerebellum) male/female pairs of stimulant-free patients with adult ADHD. Single voxel magnetic resonance spectroscopy (MRS) was used to investigate creatine (Cre), total choline (t-Cho), glutamate + glutamine (Glx), N-acetylaspartate, and myo-inositol. The mADHD and fADHD groups were compared using robust linear regression. The level of significance was corrected for multiple tests using the Benjamini-Hochberg approach.

RESULTS

For the ACC, the signals of Cre (p = 0.008) and t-Cho (p = 0.004) showed significant effects of the age covariate as well as an interaction of sex and age (Cre: p = 0.033; t-Cho: p = 0.040). For the Glx signal, an interaction of sex and age could also be observed (p = 0.033). For cerebellar neurometabolites, the signals of t-Cho (p = 0.049) and Glx (p = 0.049) showed significant effects of the factor sex.

CONCLUSION

This is the largest study yet to analyze sex differences in brain neurochemistry in adult patients with ADHD. Different age-dependent t-Cho signals in the ACC might be associated with delayed myelinization in mADHD. Further MRS studies in adult ADHD, accounting for possible sex effects, are warranted to validate the present findings.

Epigenetic signatures of smoking associate with cognitive function, brain structure, and mental and physical health outcomes in the Lothian Birth Cohort 1936

Recent advances in genome-wide DNA methylation (DNAm) profiling for smoking behaviour have given rise to a new, molecular biomarker of smoking exposure. It is unclear whether a smoking-associated DNAm (epigenetic) score has predictive value for ageing-related health outcomes which is independent of contributions from self-reported (phenotypic) smoking measures. Blood DNA methylation levels were measured in 895 adults aged 70 years in the Lothian Birth Cohort 1936 (LBC1936) study using the Illumina 450K assay. A DNA methylation score based on 230 CpGs was used as a proxy for smoking exposure. Associations between smoking variables and health outcomes at age 70 were modelled using general linear modelling (ANCOVA) and logistic regression. Additional analyses of smoking with brain MRI measures at age 73 (n = 532) were performed. Smoking-DNAm scores were positively associated with self-reported smoking status (P < 0.001, eta-squared ɳ2 = 0.63) and smoking pack years (r = 0.69, P < 0.001). Higher smoking DNAm scores were associated with variables related to poorer cognitive function, structural brain integrity, physical health, and psychosocial health. Compared with phenotypic smoking, the methylation marker provided stronger associations with all of the cognitive function scores, especially visuospatial ability (P < 0.001, partial eta-squared ɳp2 = 0.022) and processing speed (P < 0.001, ɳp2 = 0.030); inflammatory markers (all P < 0.001, ranges from ɳp2 = 0.021 to 0.030); dietary patterns (healthy diet (P < 0.001, ɳp2 = 0.052) and traditional diet (P < 0.001, ɳp2 = 0.032); stroke (P = 0.006, OR 1.48, 95% CI 1.12, 1.96); mortality (P < 0.001, OR 1.59, 95% CI 1.42, 1.79), and at age 73; with MRI volumetric measures (all P < 0.001, ranges from ɳp2 = 0.030 to 0.052). Additionally, education was the most important life-course predictor of lifetime smoking tested. Our results suggest that a smoking-associated methylation biomarker typically explains a greater proportion of the variance in some smoking-related morbidities in older adults, than phenotypic measures of smoking exposure, with some of the accounted-for variance being independent of phenotypic smoking status.

Cigarette smoking and gray matter brain volumes in middle age adults: the CARDIA Brain MRI sub-study

Cigarette smoking has been associated with dementia and dementia-related brain changes, notably gray matter (GM) volume atrophy. These associations are thought to reflect the co-morbidity of smoking and vascular, respiratory, and substance use/psychological conditions. However, the extent and localization of the smoking-GM relationship and the degree to which vascular, respiratory, and substance use/psychological factors influence this relationship remain unclear. In the Coronary Artery Risk Development in Young Adults CARDIA cohort (n = 698; 52% women; 40% black participants; age = 50.3 (SD = 3.5)), we examined the associations of smoking status with total GM volume and GM volume of brain regions linked to neurocognitive and addiction disorders. Linear regression models were used to adjust for vascular, respiratory, and substance use/psychological factors and to examine whether they modify the smoking-GM relationship. Compared to never-smokers, current smokers had smaller total GM volume (-8.86 cm³ (95%CI = -13.44, -4.29). Adjustment for substance use/psychological - but not vascular or respiratory - factors substantially attenuated this association (coefficients = -5.54 (95% CI = -10.32, -0.76); -8.33 (95% CI = -12.94, -3.72); -7.69 (95% CI = -6.95, -4.21), respectively). There was an interaction between smoking and alcohol use such that among alcohol non-users, smoking was not related to GM volumes and among alcohol users, those who currently smoked had -12 cm³ smaller total GM, specifically in the frontal and temporal lobes, amygdala, cingulate, and insula. Results suggest a large-magnitude association between smoking and smaller GM volume at middle age, accounting for vascular, respiratory, and substance use/psychological factors, and that the association was strongest in alcohol users. Regions suggested to be most vulnerable are those where cognition and addiction processes overlap.

Stroke risk among patients with chronic obstructive pulmonary disease: A systematic review and meta-analysis

Increased stroke risk among chronic obstructive pulmonary disease patients has not yet been established. In this study, we conducted a systematic review and meta-analysis to assess stroke risk among chronic obstructive pulmonary disease patients. PubMed, EMBASE, and the Cochrane Library were systematically searched from database inception until December 31, 2016 to identify longitudinal observational studies that investigated the association between chronic obstructive pulmonary disease and stroke. Stroke risk was quantified by overall and subgroup analyses, and a pooled hazard ratio was calculated. Study quality was evaluated using the Newcastle-Ottawa Scale. Publication bias was assessed using Begg's rank correlation test. Eight studies met the inclusion criteria. In a random-effects model, significantly increased stroke risk was observed among chronic obstructive pulmonary disease patients (hazard ratio, 1.30; 95% confidence interval, 1.18-1.43). In subgroup analyses stratified by stroke subtype, study quality, and adjustment by socioeconomic status, the association between increased stroke risk and chronic obstructive pulmonary disease patients was robust. Statistically significant publication bias was not detected. In summary, chronic obstructive pulmonary disease was found to be associated with increased stroke risk. Additional prospective studies are required to elucidate the mechanisms underlying the increase in stroke risk and identify effective preventive interventions.

The mid-childhood and adolescent antecedents of women's external locus of control orientation

Background: External locus of control orientation (ELOC) is a powerful predictor of adverse consequences in regard to health, educational attainment, inter-personal relationships and well-being. Although many cross-sectional studies have been carried out, relatively little is known about antecedent factors influencing the development of ELOC. Methods: Over 12,000 pregnant women who enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC) in south-west England, had completed a brief version of the Adult Nowicki-Strickland Internal-External LOC scale, together with detailed questions concerning their own parents and childhood.  A series of hypothesis-free structured backwards stepwise logistic regression analyses used an exposome approach with ELOC as the outcome. Results: Significant positive associations were found with smoking of the parents of the surveyed women, including prenatal exposure, and their own onset of regular smoking in mid-childhood (6-11 years). Increased odds of ELOC were also found with the absence of their fathers in early childhood, presence of older siblings, and with being born and brought up in the same area as they resided in at the time surveyed. Protective influences in the surveyed women included positive rating of their mother's care, having a relatively educated mother, attending boarding school, their own age (the older they were, the less likely were they to have an external orientation), having a mentally ill parent, a sibling hospitalized or a relative die. Conclusions: There are two conclusions: (i) that not all stressful events contribute to the development of ELOC and it would be essential for models of antecedents of ELOC to take note of this complexity, and (ii) there are consistent (albeit unexpected) findings that highlight associations with cigarette smoke exposure of the woman from fetal life through to when starting to smoke regularly herself in mid-childhood. It is important that these findings are tested in other populations.

The mid-childhood and adolescent antecedents of women's external locus of control orientation

Background: External locus of control orientation (ELOC) is a powerful predictor of adverse consequences in regard to health, educational attainment, inter-personal relationships and well-being. Although many cross-sectional studies have been carried out, relatively little is known about antecedent factors influencing the development of ELOC. Methods: Over 12,000 pregnant women who enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC) in south-west England, had completed a brief version of the Adult Nowicki-Strickland Internal-External LOC scale, together with detailed questions concerning their own parents and childhood.  A series of hypothesis-free structured backwards stepwise logistic regression analyses used an exposome approach with ELOC as the outcome. Results: Significant positive associations were found with smoking of the parents of the surveyed women, including prenatal exposure, and their own onset of regular smoking in mid-childhood (6-11 years). Increased odds of ELOC were also found with the absence of their fathers in early childhood, presence of older siblings, and with being born and brought up in the same area as they resided in at the time surveyed. Protective influences in the surveyed women included positive rating of their mother's care, having a relatively educated mother, attending boarding school, their own age (the older they were, the less likely were they to have an external orientation), having a mentally ill parent, a sibling hospitalized or a relative die. Conclusions: There are two conclusions: (i) that not all stressful events contribute to the development of ELOC and it would be essential for models of antecedents of ELOC to take note of this complexity, and (ii) there are consistent (albeit unexpected) findings that highlight associations with cigarette smoke exposure of the woman from fetal life through to when starting to smoke regularly herself in mid-childhood. It is important that these findings are tested in other populations.

Glutathione metabolism in the prefrontal brain of adults with high-functioning autism spectrum disorder: an MRS study

Background

Autism spectrum disorder (ASD) is a neurodevelopmental disease characterized by difficulties in social communication, unusually restricted, repetitive behavior and interests, and specific abnormalities in language and perception. The precise etiology of ASD is still unknown and probably heterogeneous. In a subgroup of patients, toxic environmental exposure might lead to an imbalance between oxidative stress and anti-oxidant systems. Previous serum and postmortem studies measuring levels of glutathione (GSH), the main cellular free radical scavenger in the brain, have supported the hypothesis that this compound might play a role in the pathophysiology of autism.

Methods

Using the method of single-voxel proton magnetic resonance spectroscopy (MRS), we analyzed the GSH signal in the dorsal anterior cingulate cortex (dACC) and the dorsolateral prefrontal cortex (DLPFC) of 24 ASD patients with normal or above average IQs and 18 matched control subjects. We hypothesized that we would find decreased GSH concentrations in both regions.

Results

We did not find overall group differences in neurometabolites including GSH, neither in the dorsal ACC (Wilks’ lambda test; p = 0.429) nor in the DLPFC (p = 0.288). In the dACC, we found a trend for decreased GSH signals in ASD patients (p = 0.076).

Conclusions

We were unable to confirm our working hypothesis regarding decreased GSH concentrations in the ASD group. Further studies combining MRS, serum, and cerebrospinal fluid measurements of GSH metabolism including other regions of interest or even whole brain spectroscopy are needed.

Increased ventricular cerebrospinal fluid lactate in depressed adolescents

BACKGROUND

Mitochondrial dysfunction has been increasingly examined as a potential pathogenic event in psychiatric disorders, although its role early in the course of major depressive disorder (MDD) is unclear. Therefore, the purpose of this study was to investigate mitochondrial dysfunction in medication-free adolescents with MDD through in vivo measurements of neurometabolites using high-spatial resolution multislice/multivoxel proton magnetic resonance spectroscopy.

METHODS

Twenty-three adolescents with MDD and 29 healthy controls, ages 12-20, were scanned at 3T and concentrations of ventricular cerebrospinal fluid lactate, as well as N-acetyl-aspartate (NAA), total creatine (tCr), and total choline (tCho) in the bilateral caudate, putamen, and thalamus were reported.

RESULTS

Adolescents with MDD exhibited increased ventricular lactate compared to healthy controls [F(1,41)=6.98, P=0.01]. However, there were no group differences in the other neurometabolites. Dimensional analyses in the depressed group showed no relation between any of the neurometabolites and symptomatology, including anhedonia and fatigue.

CONCLUSIONS

Increased ventricular lactate in depressed adolescents suggests mitochondrial dysfunction may be present early in the course of MDD; however it is still not known whether the presence of mitochondrial dysfunction is a trait vulnerability of individuals predisposed to psychopathology or a state feature of the disorder. Therefore, there is a need for larger multimodal studies to clarify these chemical findings in the context of network function.

Normal Neurochemistry in the Prefrontal and Cerebellar Brain of Adults with Attention-Deficit Hyperactivity Disorder

Attention-deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder. In an attempt to extend earlier neurochemical findings, we organized a magnetic resonance spectroscopy (MRS) study as part of a large, government-funded, prospective, randomized, multicenter clinical trial comparing the effectiveness of specific psychotherapy with counseling and stimulant treatment with placebo treatment (Comparison of Methylphenidate and Psychotherapy Study). We report the baseline neurochemical data for the anterior cingulate cortex (ACC) and the cerebellum in a case–control setting. For the trial, 1,480 adult patients were contacted for participation, 518 were assessed for eligibility, 433 were randomized, and 187 were potentially eligible for neuroimaging. The control group included 119 healthy volunteers. Single-voxel proton MRS was performed. In the patient group, 113 ACC and 104 cerebellar spectra fulfilled all quality criteria for inclusion in statistical calculations, as did 82 ACC and 78 cerebellar spectra in the control group. We did not find any significant neurometabolic differences between the ADHD and control group in the ACC (Wilks’ lambda test: p = 0.97) or in the cerebellum (p = 0.62). Thus, we were unable to replicate earlier findings in this methodologically sophisticated study. We discuss our findings in the context of a comprehensive review of other MRS studies on ADHD and a somewhat skeptical neuropsychiatric research perspective. As in other neuropsychiatric disorders, the unclear nosological status of ADHD might be an explanation for false-negative findings.

Lung disease as a determinant of cognitive decline and dementia

Almost 40 million people currently live with dementia but this is estimated to double over the next 20 years; despite this, research identifying modifiable risk factors is scarce. There is increasing evidence that cognitive impairment is more frequent in those with chronic lung disease than those without. Chronic obstructive pulmonary disease affects 210 million people, with cognitive impairment present in 60% of certain populations. Co-morbid cognitive dysfunction also appears to impact on important outcomes such as quality of life, hospitalisation and survival. This review summarises the evidence of an association between cognition, impaired lung function and obstructive lung disease. It goes on to examine the contribution of neuro-imaging to our understanding of the underlying pathophysiology. While the mechanisms of brain pathology and cognitive impairment are likely to be complex and multi-factorial, there is evidence to suggest a key role for occult cerebrovascular damage independent of traditional vascular risk factors, including smoking.

Focused transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal cortex modulates specific domains of self-regulation

Recent neuroscience theories suggest that different kinds of self-regulation may share a common psychobiological mechanism. However, empirical evidence for a domain general self-regulation mechanism is scarce. The aim of this study was to investigate whether focused anodal transcranial direct current stimulation (tDCS), facilitating the activity of the dorsolateral prefrontal cortex (dlPFC), acts on a domain general self-regulation mechanism and thus modulates both affective and appetitive self-regulation. Twenty smokers participated in this within-subject sham controlled study. Effects of anodal left, anodal right and sham tDCS over the dlPFC on affective picture appraisal and nicotine craving-cue appraisal were assessed. Anodal right tDCS over the dlPFC reduced negative affect in emotion appraisal, but neither modulated regulation of positive emotion appraisal nor of craving appraisal. Anodal left stimulation did not induce any significant effects. The results of our study show that domain specific self-regulation networks are at work in the prefrontal cortex. Focused tDCS modulation of this specific self-regulation network could probably be used during the first phase of nicotine abstinence, during which negative affect might easily result in relapse. These findings have implications for neuroscience models of self-regulation and are of relevance for the development of brain stimulation based treatment methods for neuropsychiatric disorders associated with self-regulation deficits.

Recruitment and Retention of Smokers Versus Nonsmokers in an rTMS Study

Repetitive transcranial magnetic stimulation (rTMS) is a new frontier in the examination of addictive behaviors and perhaps the development of new interventions. This study examined differences in recruitment, eligibility, and retention among smokers and nonsmokers in an rTMS study. We modeled participant eligibility and study completion among eligible participants accounting for demographic differences between smokers and nonsmokers. Nonsmokers were more likely than smokers to remain eligible for the study after the in-person screen (84.2% versus 57.4%; OR 4.0 CI: 1.0, 15.4, p=0.05) and to complete the study (87.5% versus 59.3%; OR=43.9 CI: 2.8, 687.2, p=0.007). The preliminary findings suggest that careful screening for drugs of abuse and brain abnormalities among smokers prior to administering rTMS is warranted. More research is needed concerning the prevalence of brain abnormalities in smokers. Smokers might need to be informed about a higher risk of incidental MRI findings.

Insula-specific H magnetic resonance spectroscopy reactions in heavy smokers under acute nicotine withdrawal and after oral nicotine substitution

The aim of this study was to clarify whether addiction-specific neurometabolic reaction patterns occur in the insular cortex during acute nicotine withdrawal in tobacco smokers in comparison to nonsmokers. Fourteen male smokers and 10 male nonsmokers were included. Neurometabolites of the right and the left insular cortices were quantified by magnetic resonance spectroscopy (MRS) on a 3-Tesla scanner. Three separate MRS measurements were performed in each subject: among the smokers, the first measurement was done during normal smoking behavior, the second measurement during acute withdrawal (after 24 h of smoking abstinence), and the third shortly after administration of an oral nicotine substitute. Simultaneously, craving, withdrawal symptoms, and CO levels in exhaled air were determined during the three phases. The participants in the control group underwent the same MR protocol. In the smokers, during withdrawal, the insular cortex showed a significant increase in glutamine (Gln; p = 0.023) as well as a slight increase not reaching significance for glutamine/glutamate (Glx; p = 0.085) and a nonsignificant drop in myoinositol (mI; p = 0.381). These values tended to normalize after oral nicotine substitution treatment, even though differences were not significant: Gln (p = 0.225), Glx (p = 0.107) and mI (p = 0.810). Overall, the nonsmokers (control group) did not show any metabolic changes over all three phases (p > 0.05). In smokers, acute nicotine withdrawal produces a neurometabolic reaction pattern that is partly reversed by the administration of an oral nicotine substitute. The results are consistent with the expression of an addiction-specific neurometabolic shift in the brain and confirm the fact that the insular cortex seems to play a possible role in nicotine dependence.

Lifetime cigarette smoking is associated with striatal volume measures

Nicotine, the primary addictive component of tobacco, affects the mammalian brain. Smokers' brains have smaller cortical grey matter volumes and/or lower densities compared with non-smokers'. Differences in subcortical structures like the striatum are however, less clear. A high concentration of nicotinic receptors makes the striatum a potential target for nicotine. In addition, striatal nuclei are essential components of the reward/reinforcement pathway involved in addiction. The aim of this study was to explore the relationship between striatal nuclei (caudate, putamen and nucleus accumbens area) volumes and lifetime smoking in a large community-based sample of 'young-old' individuals. Brain volumes were measured using a semi-automated method in 315 participants aged 64-70 years who were selected from a larger randomly sampled cohort and who consented to a magnetic resonance imaging scan. Multiple regression analysis was used to assess the relationship between striatal volumes and cigarette smoking measures while controlling for age, sex, intracranial and total brain volumes and general physical and mental health measures. Greater lifetime use of cigarettes (measured in pack-years) was associated with smaller left nucleus accumbens area volume (P = 0.018) and larger left putamen volume (P = 0.025). Greater putaminal volume was also associated with a lower age at smoking initiation (P = 0.004). In this generally healthy cohort, lifetime use of cigarettes is significantly associated with striatal volume measures. These changes could indicate predisposing factors for nicotine addiction, or an effect of chronic nicotine exposure or a combination of both.

Brain structure and function in chronic obstructive pulmonary disease: a multimodal cranial magnetic resonance imaging study

RATIONALE

Brain pathology is a poorly understood systemic manifestation of chronic obstructive pulmonary disease (COPD). Imaging techniques using magnetic resonance (MR) diffusion tensor imaging (DTI) and resting state functional MR imaging (rfMRI) provide measures of white matter microstructure and gray functional activation, respectively.

OBJECTIVES

We hypothesized that patients with COPD would have reduced white matter integrity and that functional communication between gray matter resting-state networks would be significantly different to control subjects. In addition, we tested whether observed differences related to disease severity, cerebrovascular comorbidity, and cognitive dysfunction.

METHODS

DTI and rfMRI were acquired in stable nonhypoxemic patients with COPD (n = 25) and compared with age-matched control subjects (n = 25). Demographic, disease severity, stroke risk, and neuropsychologic assessments were made.

MEASUREMENTS AND MAIN RESULTS

Patients with COPD (mean age, 68; FEV(1) 53 ± 21% predicted) had widespread reduction in white matter integrity (46% of white matter tracts; P < 0.01). Six of the seven resting-state networks showed increased functional gray matter activation in COPD (P < 0.01). Differences in DTI, but not rfMRI, remained significant after controlling for stroke risk and smoking (P < 0.05). White matter integrity and gray matter activation seemed to account for difference in cognitive performance between patients with COPD and control subjects.

CONCLUSIONS

In stable nonhypoxemic COPD there is reduced white matter integrity throughout the brain and widespread disturbance in functional activation of gray matter, which may contribute to cognitive dysfunction. White matter microstructural integrity but not gray matter functional activation is independent of smoking and cerebrovascular comorbidity. The mechanisms remain unclear, but may include cerebral small vessel disease caused by COPD.

The effect of curcumin in the ectonucleotidases and acetylcholinesterase activities in synaptosomes from the cerebral cortex of cigarette smoke-exposed rats

With the evidence that curcumin may be a potent neuroprotective agent and that cigarette smoke is associated with a decline in the cognitive performance as our bases, we investigated the activities of Ecto-Nucleoside Triphosphate Diphosphohydrolase (NTPDase), 5'-nucleotidase and acetylcholinesterase (AChE) in cerebral cortex synaptosomes from cigarette smoke-exposed rats treated with curcumin (Cur). The experimental procedures entailed two sets of experiments. In the first set, the groups were vehicle, Cur 12·5, 25 and 50 mg·kg(-1) ; those in the second set were vehicle, smoke, smoke and Cur 12·5, 25 and 50 mg·kg(-1) . Curcumin prevented the increased NTPDase, 5'-nucleotidase and AChE activities caused by smoke exposure. We suggest that treatment with Cur was protective because the decrease of ATP and acetylcholine (ACh) concentrations is responsible for cognitive impairment, and both ATP and ACh have key roles in neurotransmission.

Magnetic resonance spectroscopy of the anterior cingulate cortex in eating disorders

The anterior cingulate cortex plays a key role in eating disorders (ED), but it remains an open question whether there are deviations of the neurochemistry of this region in patients with ED. Seventeen adult female patients with ED (10 with bulimia nervosa, 7 with anorexia nervosa) were compared to 14 matched female healthy controls using single voxel magnetic resonance spectroscopy of the anterior cingulate cortex. Group comparisons did not reveal any differences between patients and controls, but a positive correlation between glutamate and myo-inositol signals with "drive for thinness" in patients with bulimia nervosa was found in exploratory correlation analyses.

Neuromodulation of decision-making in the addictive brain

Noninvasive brain stimulation of the dorsolateral prefrontal cortex with repetitive transcranial magnetic stimulation and transcranial direct current stimulation can modify decision-making behaviors in healthy subjects. The same type of noninvasive brain stimulation can suppress drug craving in substance user patients, who often display impaired decision-making behaviors. We discuss the implications of these studies for the cognitive neurosciences and their translational applications to the treatment of addictions. We propose a neurocognitive model that can account for our findings and suggests a promising therapeutic role of brain stimulation in the treatment of substance abuse and addictive behavior disorders.