Regional cerebral blood flow and neuropsychological functioning in early and late onset alcoholism

A New Way Forward: How Brain SPECT Imaging Can Improve Outcomes and Transform Mental Health Care Into Brain Health Care

In the past three decades, brain single-photon-emission-computed-tomography (SPECT) imaging has garnered a significant, evidence-based foundation for a wide array of indications relevant to the field of clinical psychiatry, including dementia, traumatic brain injuries, seizures, cerebrovascular disease, complex neuropsychiatric presentations, and treatment-resistant disorders. In clinical psychiatric practice, however, SPECT remains underutilized. Only a small percentage of psychiatric clinicians use brain imaging technology. In this article, the authors provide a rationale for shifting the paradigm to one that includes broader use of SPECT in the clinical psychiatric setting, primarily for patients with complex conditions. This paper will outline seven specific clinical applications. Adding neuroimaging tools like SPECT to day-to-day clinical practice can help move psychiatry forward by transforming mental health care, which can be stigmatizing and often shunned by the general public, to brain health care, which the authors argue will be more likely to be embraced by a larger group of people in need.

Attenuated cerebral blood flow in frontolimbic and insular cortices in Alcohol Use Disorder: Relation to working memory

Chronic, excessive alcohol consumption is associated with cerebrovascular hypoperfusion, which has the potential to interfere with cognitive processes. Magnetic resonance pulsed continuous arterial spin labeling (PCASL) provides a noninvasive approach for measuring regional cerebral blood flow (CBF) and was used to study 24 men and women with Alcohol Use Disorder (AUD) and 20 age- and sex-matched controls. Two analysis approaches tested group differences: a data-driven, regionally-free method to test for group differences on a voxel-by-voxel basis and a region of interest (ROI) approach, which focused quantification on atlas-determined brain structures. Whole-brain, voxel-wise quantification identified low AUD-related cerebral perfusion in large volumes of medial frontal and cingulate cortices. The ROI analysis also identified lower CBF in the AUD group relative to the control group in medial frontal, anterior/middle cingulate, insular, and hippocampal/amygdala ROIs. Further, years of AUD diagnosis negatively correlated with temporal cortical CBF, and scores on an alcohol withdrawal scale negatively correlated with posterior cingulate and occipital gray matter CBF. Regional volume deficits did not account for AUD CBF deficits. Functional relevance of attenuated regional CBF in the AUD group emerged with positive correlations between episodic working memory test scores and anterior/middle cingulum, insula, and thalamus CBF. The frontolimbic and insular cortical neuroconstellation with dampened perfusion suggests a mechanism of dysfunction associated with these brain regions in AUD.

Widespread Cognitive Deficits in Alcoholism Persistent Following Prolonged Abstinence: An Updated Meta-analysis of Studies That Used Standardised Neuropsychological Assessment Tools

Objective

This study presents an updated meta-analysis replicating the study of (Stavro, K., Pelletier, J., & Potvin, S. (2013). Widespread and sustained cognitive deficits in alcoholism: A meta-analysis. Addiction Biology, 18, 203–213. doi:10.1111/j.1369-1600.2011.00418.x) regarding the cognitive functioning of alcoholics as a function of time abstinent.

Methods

A total of 34 studies (including a total of 2,786 participants) that met pre-determined inclusion and exclusion criteria were included in the analyses. The alcoholics were categorised into recently detoxified alcoholics (0–31 days sober), alcoholics 32–365 days sober and alcoholics >365 days sober consistent with the previous study. The current study employed more stringent control on the tests included in the analysis to include only those tasks described in contemporary neuropsychological test compendia. Forty-seven percent of the papers surveyed were not include in the previous meta-analysis.

Results

The results indicated that there was a diffuse and pervasive pattern of cognitive deficit among recently detoxified alcoholics and that these deficits, particularly with regard to memory functioning, persisted even in longer term abstinent alcoholics. This was inconsistent with the prior meta-analysis which contended that significant cognitive recovery was possible after as little as 1 year.

Conclusion

The persisting cognitive deficits were noted across a wide range of cognitive functions, supporting the notion of a diffuse rather than a specific compromise of cognition in alcoholism following discontinuation, as measured using standardised neuropsychological tests. Limitations on the finding included the fact that it was a cross-sectional rather than a longitudinal analysis, was subject to heterogeneity of method, had low representation of females in the samples, and had fewer studies of long-term sober samples.

Earlier alcohol use onset prospectively predicts changes in functional connectivity

BACKGROUND

Half of all new alcohol initiates are between 12 and 17 years old. This is a period of intense neurodevelopment, including changes in functional connectivity patterns among higher-order function areas. It is crucial to understand how alcohol-related neurotoxicity may be influenced by drinking onset age.

DESIGN

This study prospectively examined the effects of age of first drink on frontoparietal context-dependent functional connectivity (cdFC) during a visual working memory task. Youth 13.5 years of age (SD = 1.2) underwent a neuropsychological and neuroimaging session before drinking initiation and at follow-up 6 years later. Hierarchical linear regressions examined if youth with earlier ages of onset for first and weekly alcohol use showed higher follow-up cdFC between the dorsolateral prefrontal cortex and posterior parietal cortex regions of interest and whole-brain exploratory regions, controlling for pre-drinking cdFC. Higher follow-up cdFC was hypothesized to be correlated with poorer performances in neuropsychological performance.

RESULTS

Exploratory whole-brain analyses showed that, as hypothesized, earlier ages of weekly drinking onset were associated with higher cdFC between the bilateral posterior cingulate and cortical and subcortical areas implicated in attentional processes, which was in turn associated with poorer performance on neuropsychological tasks of attention, ps < .05. No relationship between age of onset and cdFC between the two ROIs were found.

CONCLUSION

Earlier ages of weekly alcohol use initiation may adversely affect neurodevelopment by reducing developmentally appropriate integration of attentional circuits during a cognitive challenge. Delaying the onset of weekly alcohol use patterns well after early adolescence may reduce the risk for harm of alcohol use on the brain.

Earlier Alcohol Use Onset Predicts Poorer Neuropsychological Functioning in Young Adults

BACKGROUND

Neurodevelopment may be shaped by environmental factors such as alcohol intake. Over 20% of U.S. high school students begin drinking before age 14, and those who initiated drinking before age 14 are 4 times more likely to develop psychosocial, psychiatric, and substance use difficulties than those who began drinking after turning 20. Little is known, however, about how the age of alcohol use onset influences brain development.

METHODS

This study prospectively examined the effects of alcohol use onset age on neurocognitive functioning in healthy adolescent drinkers (N = 215). Youth were administered a neuropsychological battery before substance use initiation (M = 13.6 years, SD = 0.8) and on average 6.8 years later (M = 20.2 years, SD = 1.5). Hierarchical linear regressions examined if earlier ages of onset for first and regular (i.e., weekly) alcohol use adversely influenced neurocognition, above and beyond baseline neurocognition, substance use severity, and familial and social environment factors.

RESULTS

As hypothesized, an earlier age of first drinking onset (AFDO) predicted poorer performance in the domains of psychomotor speed and visual attention (ps<0.05, N = 215) and an earlier age of weekly drinking onset (AWDO) predicted poorer performances on tests of cognitive inhibition and working memory, controlling for baseline neuropsychological performance, drinking duration, and past-year marijuana use (ps<0.05, N = 127). No relationship between AFDO and AWDO was found with verbal learning and memory and visuospatial ability.

CONCLUSIONS

This is the first study to assess the association between age of adolescent drinking onset and neurocognitive performance using a comprehensive test battery. This study suggests that early onset of drinking increases risk for alcohol-related neurocognitive vulnerabilities and that initiation of any or weekly alcohol use at younger ages appears to be a risk factor for poorer subsequent neuropsychological functioning. Findings have important implications for public policies related to the legal drinking age and prevention programming. Further studies are needed to replicate these preliminary findings and better understand mediating processes and moderating conditions.

Frontal lobe executive dysfunction and cerebral perfusion study in alcohol dependence syndrome

BACKGROUND

Long-term alcohol use leading to frontal lobe impairment has been a cause of concern for many decades. However, there are very few studies from India of evaluation of frontal lobe executive dysfunction among alcoholics. Hence, this study was undertaken to evaluate the frontal executive dysfunction using Wisconsin Card Sorting Test (WCST) and perfusion deficits by Single-Photon Emission Computerized Tomography (SPECT) among alcohol-dependent patients.

AIM

The aim of this study is to evaluate the frontal executive dysfunction using WCST and frontal lobe perfusion deficits by SPECT among alcohol-dependent patients.

MATERIALS AND METHODS

This was a cross-sectional study involving 20 alcohol dependence syndrome patients in a tertiary care center. After ethical clearance and informed consent, all were evaluated using WCST and SPECT.

RESULTS

About 45% patients had impairment on WCST, and it was related to the duration of drinking. About 55% showed reduced frontal lobe perfusion on SPECT scan and they had a long duration of drinking compared to controls. Among the patients showing impairment on WCST subscores, more than 50% had reduced frontal lobe perfusion on SPECT.

CONCLUSION

This study not only confirmed the executive function impairment and frontal lobe perfusion deficits in alcohol-dependent patients but also showed a concomitant presence of both in patients with chronic alcohol abuse.

Alcohol use and depression during adolescence and young adulthood: a summary and interpretation of mixed findings

Alcohol Use Disorder (AUD) and alcohol misuse are common among adolescents and young adults and are associated with significant personal and societal problems. Similarly, Major Depressive Disorder (MDD) and depressive symptoms are prevalent in this population and when they co-occur with alcohol misuse lead to even more severe consequences. Numerous studies have investigated the association between depressive symptoms, AUD and various drinking behaviors presenting an unclear picture. In this review we summarize studies among adolescents and young adults that have examined these relationships. From this review it emerges that several factors affect results, including study design (cross-sectional vs longitudinal), participants' age (adolescents vs young adults), severity of problems considered (AUD vs heavy drinking; MDD vs depressive symptoms), and gender. Adolescents with AUD are at higher risk for MDD in particular at a younger age. During adolescence, several drinking behaviors, including weekly alcohol use and heavy drinking, increase the risk for depressive symptoms and MDD, while during young adulthood primarily AUD, but not other drinking behaviors, is associated with increased risk for MDD. Gender may have an effect on the association between depression and drinking behaviors but its role is still unclear. Some evidence suggests that the association between AUD and MDD is bidirectional such that mood problems contribute to the onset of alcohol problems and vice-versa. More longitudinal studies are needed to examine these associations in young adults and to clarify the effect of gender on these associations. To date, findings suggest the critical need to reduce any alcohol use at a young age and to treat both depressive symptoms and AUD to prevent the occurrence of comorbid disorders.

T2 relaxation time alterations underlying neurocognitive deficits in alcohol-use disorders (AUD) in an Indian population: A combined conventional ROI and voxel-based relaxometry analysis

Long-term heavy alcohol consumption has traditionally been associated with impaired cognitive abilities, such as deficits in abstract reasoning, problem solving, verbal fluency, memory, attention, and visuospatial processing. The present study aimed at exploring these neuropsychological deficits in alcohol-use disorders (AUD) in an Indian population using the Postgraduate Institute Battery of Brain Dysfunction (PGIBBD) and their possible correlation with alterations in T2 relaxation times (T2-RT), using whole-brain voxel-based relaxometry (VBR) and conventional region of interest (ROI) approach. Multi-echo T2 mapping sequence was performed on 25 subjects with AUD and 25 healthy controls matched for age, education, and socioeconomic status. Whole-brain T2-RT measurements were conducted using VBR and conventional ROI approach. The study was carried out on a 3T whole-body MR scanner. Post processing for VBR and ROI analysis was performed using SPM 8 software and vendor-provided software, respectively. A PGIBBD test battery was conducted on all subjects to assess their cognitive abilities, and the results were reported as raw scores. VBR and ROI results revealed that AUD subjects showed prolonged T2-RTs in cerebellum bilaterally, parahippocampal gyrus bilaterally, right anterior cingulate cortex, left superior temporal gyrus, left middle frontal gyrus, and left calcarine gyrus. A significant correlation was also observed between the neuropsychological test raw scores and alterations in T2-RT in AUD subjects. Our results are consistent with previous studies suggesting tissue disruption or gliosis or demyelination as a possible reason for prolonged T2-RTs. This damage to brain tissue, which is evident as prolonged T2-RT, could possibly be associated with impaired cognitive abilities noticeable in AUD subjects.

Brain perfusion in polysubstance users: relationship to substance and tobacco use, cognition, and self-regulation

BACKGROUND

Brain perfusion is altered in both alcohol dependence and stimulant dependence. Although most substance users also abuse/depend on alcohol concurrently (polysubstance users; PSU), rigorous perfusion research in PSU is limited. Also, the relationships of perfusion abnormalities with cognition, impulsivity, or decision making are not well known.

METHODS

Arterial spin labeling MRI and neuropsychological measures assessed perfusion levels and neurocognition in 20 alcohol-dependent individuals with comorbid-stimulant dependence (PSU), 26 individuals dependent on alcohol only (ALC), and 31 light/non-drinking controls (LD). The patient groups included smokers and non-smokers.

RESULTS

ALC had lower perfusion than LD in subcortical and cortical brain regions including the brain reward/executive oversight system (BREOS). Contrary to our hypothesis, regional perfusion was generally not lower in PSU than ALC. However, smoking PSU had lower perfusion than smoking ALC in several regions, including BREOS. Lower BREOS perfusion related to greater drinking severity in smoking substance users and to greater smoking severity in smoking ALC. Lower regional perfusion in ALC and PSU correlated with worse performance in different cognitive domains; smoking status affected perfusion-cognition relationships in ALC only. Lower BREOS perfusion in both substance using groups related to higher impulsivity.

CONCLUSION

Although regional perfusion was not decreased in PSU as a group, the combination of cigarette smoking and polysubstance use is strongly related to hypoperfusion in important cortical and subcortical regions. As lower perfusion relates to greater smoking severity, worse cognition and higher impulsivity, smoking cessation is warranted for treatment-seeking PSU and ALC.

Cognitive functioning in older adults with early, late, and very late onset alcohol dependence

BACKGROUND

Alcohol dependence in older adults is associated with cognitive impairment. Age of onset of alcohol dependence is an important criterion to distinguish subgroups of alcohol-dependent people. Little is known about the influence of the age of onset of alcohol dependence on cognitive functioning. The primary aim of this study was to examine if older alcohol-dependent people with early, late or very late onset of alcohol dependence differ in terms of cognitive dysfunction.

METHODS

A total of eighty-five older alcohol-dependent people who were admitted to an inpatient detoxification program, were categorized into three age of onset groups: early onset (< 25 years: N = 27, mean age 57.7 ± 7.4), late onset (25-44 years: N = 28, mean age 61.1 ± 6.7) and very late onset (≥ 45 years: N = 30, mean age 65.6 ± 6.5). A neuropsychological test battery (Kaufman-Short Neuropsychological Assessment Procedure (K-SNAP), Trail Making Test (TMT) and Stroop Color Word Test) was administered to assess cognitive functioning. Differences between groups were examined with analyses of variance (ANOVAs).

RESULTS

There were no significant differences in performance on any of the neuropsychological measures between the three age of onset groups. However, compared to a non-alcohol-dependent norm group, all three age of onset groups performed below average.

CONCLUSIONS

The results suggest that older adults who start drinking heavily (very) late in life have similar cognitive impairments compared to their peers who have been drinking for decades. This emphasizes the vulnerability of the aging brain to the toxic effects of alcohol.

Decreased white matter integrity in fronto-occipital fasciculus bundles: relation to visual information processing in alcohol-dependent subjects

Chronic alcohol abuse is characterized by impaired cognitive abilities with a more severe deficit in visual than in verbal functions. Neuropathologically, it is associated with widespread brain structural compromise marked by gray matter shrinkage, ventricular enlargement, and white matter degradation. The present study sought to increase current understanding of the impairment of visual processing abilities in alcohol-dependent subjects, and its correlation with white matter microstructural alterations, using diffusion tensor imaging (DTI). To that end, a DTI study was carried out on 35 alcohol-dependent subjects and 30 healthy male control subjects. Neuropsychological tests were assessed for visual processing skills and deficits were reported as raw dysfunction scores (rDyS). Reduced FA (fractional anisotropy) and increased MD (mean diffusivity) were observed bilaterally in inferior and superior fronto-occipital fasciculus (FOF) fiber bundles. A significant inverse correlation in rDyS and FA values was observed in these fiber tracts whereas a positive correlation of these scores was found with the MD values. Our results suggest that FOF fiber bundles linking the frontal lobe to occipital lobe might be related to visual processing skills. This is the first report of an alteration of the white matter microstructure of FOF fiber bundles that might have functional consequences for visual processing in alcohol-dependent subjects who exhibit no neurological complications.

Brain docosahexaenoic acid [DHA] incorporation and blood flow are increased in chronic alcoholics: a positron emission tomography study corrected for cerebral atrophy

OBJECTIVE

Chronic alcohol dependence has been associated with disturbed behavior, cerebral atrophy and a low plasma concentration of docosahexaenoic acid (DHA, 22∶6n-3), particularly if liver disease is present. In animal models, excessive alcohol consumption is reported to reduce brain DHA concentration, suggesting disturbed brain DHA metabolism. We hypothesized that brain DHA metabolism also is abnormal in chronic alcoholics.

METHODS

We compared 15 non-smoking chronic alcoholics, studied within 7 days of their last drink, with 22 non-smoking healthy controls. Using published neuroimaging methods with positron emission tomography (PET), we measured regional coefficients (K*) and rates (J(in)) of DHA incorporation from plasma into the brain of each group using [1-(11)C]DHA, and regional cerebral blood flow (rCBF) using [(15)O]water. Data were partial volume error corrected for brain atrophy. Plasma unesterified DHA concentration also was quantified.

RESULTS

Mean K* for DHA was significantly and widely elevated by 10-20%, and rCBF was elevated by 7%-34%, in alcoholics compared with controls. Unesterified plasma DHA did not differ significantly between groups nor did whole brain J(in), the product of K* and unesterified plasma DHA concentration.

DISCUSSION

Significantly higher values of K* for DHA in alcoholics indicate increased brain avidity for DHA, thus a brain DHA metabolic deficit vis-à-vis plasma DHA availability. Higher rCBF in alcoholics suggests increased energy consumption. These changes may reflect a hypermetabolic state related to early alcohol withdrawal, or a general brain metabolic change in chronic alcoholics.

A selective insular perfusion deficit contributes to compromised salience network connectivity in recovering alcoholic men

BACKGROUND

Alcoholism can disrupt neural synchrony between nodes of intrinsic functional networks that are maximally active when resting relative to engaging in a task, the default mode network (DMN) pattern. Untested, however, are whether the DMN in alcoholics can rebound normally from the relatively depressed task state to the active resting state and whether local perfusion deficits could disrupt network synchrony when switching from conditions of rest to task to rest, thereby indicating a physiological mechanism of neural network adaptation capability.

METHODS

Whole-brain, three-dimensional pulsed-continuous arterial spin labeling provided measurements of regional cerebral blood flow (CBF) in 12 alcoholics and 12 control subjects under three conditions: pretask rest, spatial working-memory task, and posttask rest.

RESULTS

With practice, alcoholics and control subjects achieved similar task accuracy and reaction times. Both groups exhibited a high-low-high pattern of perfusion levels in DMN regions during the rest-task-rest runs and the opposite pattern in posterior and cerebellar regions known to be associated with spatial working memory. Alcoholics showed selective differences from control subjects in the rest-task-rest CBF pattern in the anterior precuneus and CBF level in the insula, a hub of the salience network. Connectivity analysis identified activation synchrony from an insula seed to salience nodes (parietal, medial frontal, anterior cingulate cortices) in control subjects only.

CONCLUSIONS

We propose that attenuated insular CBF is a mechanism underlying compromised connectivity among salience network nodes. This local perfusion deficit in alcoholics has the potential to impair ability to switch from cognitive states of interoceptive cravings to cognitive control for curbing internal urges.

Prenatal alcohol exposure affects vasculature development in the neonatal brain

OBJECTIVE

In humans, antenatal alcohol exposure elicits various developmental disorders, in particular in the brain. Numerous studies focus on the deleterious effects of alcohol on neural cells. Although recent studies suggest that alcohol can affect angiogenesis in adults, the impact of prenatal alcohol exposure on brain microvasculature remains poorly understood.

METHODS

We used a mouse model to investigate effects of prenatal alcohol exposure on the cortical microvascular network in vivo and ex vivo and the action of alcohol, glutamate, and vascular endothelial growth factor A (VEGF) on activity, plasticity, and survival of microvessels. We used quantitative reverse transcriptase polymerase chain reaction, Western blot, immunohistochemistry, calcimetry, and videomicroscopy. We characterized the effect of prenatal alcohol exposure on the cortical microvascular network in human controls and fetal alcohol syndrome (FAS)/partial FAS (pFAS) patients at different developmental stages.

RESULTS

In mice, prenatal alcohol exposure induced a reduction of cortical vascular density, loss of the radial orientation of microvessels, and altered expression of VEGF receptors. Time-lapse experiments performed on brain slices revealed that ethanol inhibited glutamate-induced calcium mobilization in endothelial cells, affected plasticity, and promoted death of microvessels. These effects were prevented by VEGF. In humans, we evidenced a stage-dependent alteration of the vascular network in the cortices of fetuses with pFAS/FAS. Whereas no modification was observed from gestational week 20 (WG20) to WG22, the radial organization of cortical microvessels was clearly altered in pFAS/FAS patients from WG30 to WG38.

INTERPRETATION

Prenatal alcohol exposure affects cortical angiogenesis both in mice and in pFAS/FAS patients, suggesting that vascular defects contribute to alcohol-induced brain abnormalities.

Dare to delay? The impacts of adolescent alcohol and marijuana use onset on cognition, brain structure, and function

Throughout the world, drug and alcohol use has a clear adolescent onset (Degenhardt et al., 2008). Alcohol continues to be the most popular drug among teens and emerging adults, with almost a third of 12th graders and 40% of college students reporting recent binge drinking (Johnston et al., 2009, 2010), and marijuana (MJ) is the second most popular drug in teens (Johnston et al., 2010). The initiation of drug use is consistent with an overall increase in risk-taking behaviors during adolescence that coincides with significant neurodevelopmental changes in both gray and white matter (Giedd et al., 1996a; Paus et al., 1999; Sowell et al., 1999, 2002, 2004; Gogtay et al., 2004; Barnea-Goraly et al., 2005; Lenroot and Giedd, 2006). Animal studies have suggested that compared to adults, adolescents may be particularly vulnerable to the neurotoxic effects of drugs, especially alcohol and MJ (see Schneider and Koch, 2003; Barron et al., 2005; Monti et al., 2005; Cha et al., 2006; Rubino et al., 2009; Spear, 2010). In this review, we will provide a detailed overview of studies that examined the impact of early adolescent onset of alcohol and MJ use on neurocognition (e.g., Ehrenreich et al., 1999; Wilson et al., 2000; Tapert et al., 2002a; Hartley et al., 2004; Fried et al., 2005; Townshend and Duka, 2005; Medina et al., 2007a; McQueeny et al., 2009; Gruber et al., 2011, 2012; Hanson et al., 2011; Lisdahl and Price, 2012), with a special emphasis on recent prospective longitudinal studies (e.g., White et al., 2011; Hicks et al., 2012; Meier et al., 2012). Finally, we will explore potential clinical and public health implications of these findings.

Altered cerebral blood flow and neurocognitive correlates in adolescent cannabis users

RATIONALE

The effects of adolescent marijuana use on the developing brain remain unclear, despite its prevalence. Arterial spin labeling (ASL) is a noninvasive imaging technique that characterizes neurovascular status and cerebral blood flow (CBF), potentially revealing contributors to neuropathological alterations. No studies to date have looked at CBF in adolescent marijuana users.

OBJECTIVES

This study examined CBF in adolescent marijuana users and matched healthy controls at baseline and after 4 weeks of monitored abstinence.

METHODS

Heavy adolescent marijuana users (n = 23, >200 lifetime marijuana use days) and demographically matched controls (n = 23) with limited substance exposure underwent an ASL brain scan at an initial session and after 4 weeks of sequential urine toxicology to confirm abstinence.

RESULTS

Marijuana users showed reduced CBF in four cortical regions including the left superior and middle temporal gyri, left insula, left and right medial frontal gyrus, and left supramarginal gyrus at baseline; users showed increased CBF in the right precuneus at baseline, as compared to controls (corrected p values < 0.05). No between group differences were found at follow-up.

CONCLUSIONS

Marijuana use may influence CBF in otherwise healthy adolescents acutely; however, group differences were not observed after several weeks of abstinence. Neurovascular alterations may contribute to or underlie changes in brain activation, neuropsychological performance, and mood observed in young cannabis users with less than a month of abstinence.

Widespread and sustained cognitive deficits in alcoholism: a meta-analysis

The cognitive repercussions of alcohol dependence are well documented. However, the literature remains somewhat ambiguous with respect to which distinct cognitive functions are more susceptible to impairment in alcoholism and to how duration of abstinence affects cognitive recovery. Some theories claim alcohol negatively affects specific cognitive functions, while others assert that deficits are more diffuse in nature. This is the first meta-analysis to examine cognition in alcohol abuse/dependence and the duration of abstinence necessary to achieve cognitive recovery. A literature search yielded 62 studies that assessed cognitive dysfunction among alcoholics. Effect size estimates were calculated using the Comprehensive Meta-Analysis V2, for the following 12 cognitive domains: intelligence quotient, verbal fluency/language, speed of processing, working memory, attention, problem solving/executive functions, inhibition/impulsivity, verbal learning, verbal memory, visual learning, visual memory and visuospatial abilities. Within these 12 domains, three effect size estimates were calculated based on abstinence duration. The three groups were partitioned into short- (< 1 month), intermediate- (2 to 12 months) and long- (> 1 year) term abstinence. Findings revealed moderate impairment across 11 cognitive domains during short-term abstinence, with moderate impairment across 10 domains during intermediate term abstinence. Small effect size estimates were found for long-term abstinence. These results suggest significant impairment across multiple cognitive functions remains stable during the first year of abstinence from alcohol. Generally, dysfunction abates by 1 year of sobriety. These findings support the diffuse brain hypothesis and suggest that cognitive dysfunction may linger for up to an average of 1 year post-detoxification from alcohol.

Atrophy of the parahippocampal gyrus and regional cerebral blood flow in the limbic system in chronic alcoholic patients

This study investigated regional cerebral flood flow (CBF) in chronic alcoholic patients, focusing primarily on the limbic system, including the hippocampus and the callosomarginal region, because of their susceptibility to damage in such patients. The degree of hippocampal atrophy in such patients was also examined. Regional CBF and the degree of parahippocampal gyrus atrophy were studied in 22 chronic alcoholic male patients with no neurological or psychological symptom (mean age, 59.3+/-4.1 years). Their findings were compared with those of 22 age-matched, male, normal controls (mean age, 59.7+/-3.9 years). Single-photon emission computed tomography was performed using the (99m)Tc-ethylcysteinate dimer ( (99m)Tc-ECD) Patlak Plot method, and the three-dimensional stereotaxic region of interest (ROI) template (3DSRT) and the fine stereotaxic ROI template (fine SRT) developed by Takeuchi et al were used to evaluate regional CBF, focusing primarily on the limbic system. These methods make it possible to precisely and objectively measure the details of regional CBF. The voxel-based specific regional analysis system for Alzheimer's disease (VSRAD) was used to determine the degree of parahippocampal gyrus atrophy in chronic alcoholic patients. VSRAD is a method developed by Hirata et al for evaluating the degree of atrophy of the parahippocampal gyrus. The results were analyzed using Z scores (>2 indicating significant atrophy). Blood flows in the callosomarginal region, pericallosal region, thalamus, hippocampus, parahippocampal gyrus, amygdaloid body, anterior cingulate gyrus, and middle cingulate gyrus were lower in the chronic alcoholic group than in the control group. Parahippocampal gyrus atrophy was not observed in the control group (average Z score, 0.62+/-0.29). In contrast, an atrophic tendency was observed in the chronic alcoholic group (average Z score, 1.88+/-0.44). Clinically intact, chronic alcoholic patients with no neurological or psychological symptom had decreased CBF in the limbic system and a tendency to parahippocampal gyrus atrophy.

Regional cerebral blood flow in patients with alcohol-related dementia: a SPECT study

The purpose of this study was to investigate regional cerebral blood flow (rCBF) changes using 1110 MBq of Tc-99m ECD SPECT in alcohol-related dementia (ARD) patients. Twenty-five patients with ARD and 22 healthy control subjects were included in the study. Mini-Mental Status Examination was applied to the patients and controls. The ARD patients showed drastically reduced rCBF in the frontal cortices, basal ganglia, and thalami. The results indicate that ARD is associated with hypoperfusion in both cortical and subcortical regions. These findings support previous studies suggesting the association with both cortical and subcortical neuropathology in ARD patients.

A history of alcohol dependence increases the incidence and severity of postoperative cognitive dysfunction in cardiac surgical patients

Postoperative cognitive dysfunction (POCD) commonly occurs after cardiac surgery. We tested the hypothesis that a history of alcohol dependence is associated with an increased incidence and severity of POCD in male patients undergoing cardiac surgery using cardiopulmonary bypass. Recent verbal and nonverbal memory and executive functions were assessed before and one week after surgery in patients with or without a history of alcohol dependence. Cognitive function was significantly reduced after cardiac surgery in patients with versus without a history of alcohol dependence. The results suggest that a history of alcohol dependence increases the incidence and severity of POCD after cardiac surgery.

Decreased volume of the brain reward system in alcoholism

BACKGROUND

Reinforcement of behavioral responses involves a complex cerebral circuit engaging specific neuronal networks that are modulated by cortical oversight systems affiliated with emotion, memory, judgment, and decision making (collectively referred to in this study as the "extended reward and oversight system" or "reward network"). We examined whether reward-network brain volumes are reduced in alcoholics and how volumes of subcomponents within this system are correlated with memory and drinking history.

METHODS

Morphometric analysis was performed on magnetic resonance brain scans in 21 abstinent long-term chronic alcoholic men and 21 healthy control men, group-matched on age, verbal IQ, and education. We derived volumes of total brain and volumes of cortical and subcortical reward-related structures including the dorsolateral-prefrontal, orbitofrontal, cingulate cortices, and the insula, as well as the amygdala, hippocampus, nucleus accumbens septi (NAc), and ventral diencephalon.

RESULTS

Morphometric analyses of reward-related regions revealed decreased total reward-network volume in alcoholic subjects. Volume reduction was most pronounced in right dorsolateral-prefrontal cortex, right anterior insula, and right NAc, as well as left amygdala. In alcoholics, NAc and anterior insula volumes increased with length of abstinence, and total reward-network and amygdala volumes correlated positively with memory scores.

CONCLUSIONS

The observation of decreased reward-network volume suggests that alcoholism is associated with alterations in this neural reward system. These structural reward system deficits and their correlation with memory scores elucidate underlying structural-functional relationships between alcoholism and emotional and cognitive processes.

Genuine episodic memory deficits and executive dysfunctions in alcoholic subjects early in abstinence

BACKGROUND

Chronic alcoholism is known to impair episodic memory function, but the specific nature of this impairment is still unclear. Moreover, it has never been established whether episodic memory deficit in alcoholism is an intrinsic memory deficit or whether it has an executive origin. Thus, the objectives are to specify which episodic memory processes are impaired early in abstinence from alcohol and to determine whether they should be regarded as genuine memory deficits or rather as the indirect consequences of executive impairments.

METHODS

Forty recently detoxified alcoholic inpatients at alcohol entry treatment and 55 group-matched controls underwent a neuropsychological assessment of episodic memory and executive functions. The episodic memory evaluation consisted of 3 tasks complementing each other designed to measure the different episodic memory components (learning, storage, encoding and retrieval, contextual memory, and autonoetic consciousness) and 5 executive tasks testing capacities of organization, inhibition, flexibility, updating, and integration.

RESULTS

Compared with control subjects, alcoholic patients presented impaired learning abilities, encoding processes, retrieval processes, contextual memory and autonoetic consciousness. However, there was no difference between the 2 groups regarding the storage capacities assessed by the rate of forgetting. Concerning executive functions, alcoholic subjects displayed deficits in each executive task used. Nevertheless, stepwise regression analyses showed that only performances on fluency tasks were significantly predictive of some of the episodic memory disorders (learning abilities for 40%, encoding processes for 20%, temporal memory for 21%, and state of consciousness associated with memories for 26%) in the alcoholic group.

DISCUSSION

At alcohol treatment entry, alcoholic patients present genuine episodic memory deficits that cannot be regarded solely as the consequences of executive dysfunctions. These results are in accordance with neuroimaging findings showing hippocampal atrophy. Moreover, given the involvement of episodic memory and executive functions in alcohol treatment, these data could have clinical implications.

Gender Differences in Neurocognitive Functioning Among Alcohol-Dependent Russian Patients

BACKGROUND

There are a limited number of studies that have examined gender differences in the neurocognitive test performances of alcohol-dependent individuals. Those that have been conducted reported that compared with men, women's visuospatial skills, psychomotor speed, and working memory are more profoundly affected by chronic alcohol abuse despite a shorter duration of drinking and a lesser quantity of alcohol consumed.

METHODS

The performances of Russian male and female alcoholic and nonalcoholic control subjects were compared on a series of neurocognitive tasks that assess motor speed, visuoperceptual processing, visuospatial processing, decision making, and cognitive flexibility.

RESULTS

Group and gender differences emerged on specific components of each task administered. Female compared with male alcoholic subjects exhibited poorer performances on tests of visual working memory, spatial planning and problem solving, and cognitive flexibility.

CONCLUSION

The data support and extend prior research demonstrating a more deleterious impact of alcohol dependence on female alcoholic subjects' cognitive functioning compared with male alcoholic subjects. Several theories are offered to account for gender differences in neurocognitive performance.

Measurement of cerebral perfusion with arterial spin labeling: Part 2. Applications

Arterial spin labeling (ASL) uses magnetic resonance imaging methods to measure cerebral blood flow (CBF) non-invasively. ASL CBF validly localizes brain function and may be especially useful for studies where the time frame of behavioral change is more than a few minutes, such as in longitudinal and treatment studies. ASL measures of cerebral perfusion are highly accurate in detecting lesion laterality in temporal lobe epilepsy, stenotic-occlusive disease, and brain tumors. Among lesioned patients, ASL CBF has excellent concurrent validity when correlated with CBF measured by Positron Emission Tomography or with dynamic susceptibility-weighted magnetic resonance. ASL CBF can predict tumor grading in vivo and can predict six-month response to the surgical treatment of brain tumors. ASL's capability to selectively and non-invasively tag flow in major vessels may refine the monitoring of treatment of cerebrovascular disease and brain tumors. Conclusions about the utility of ASL are limited by the small sample sizes of the studies currently in the literature and by the uncertainty caused by the effect of brain disease on transit times of the magnetic tag. As the method evolves, ASL techniques will likely become more widely used in clinical research and practice.

Theory of mind, humour processing and executive functioning in alcoholism

AIMS

Alcoholism is associated with cognitive deficits, which have been interpreted in terms of a specific vulnerability of the frontal lobes to the toxic effects of alcohol. While executive functions in alcoholism have been investigated extensively, only little work has been carried out on social cognition. The aim of the present study was to investigate the association between executive functions, theory of mind and humour processing in alcoholism.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

A comprehensive neuropsychological test battery was administered to 29 alcoholic patients (Alc) and 29 healthy controls (HC). The test battery included measurements of affect, general intellectual abilities, executive functions, humour processing and theory of mind. The two groups were comparable with respect to affective variables, IQ, gender and age.

FINDINGS AND CONCLUSIONS

Group comparisons revealed cognitive as well as affective humour processing deficits of alcoholics in comparison with HC. The observed impairments were related to theory of mind and executive functions. The deficits may contribute to interpersonal problems and are thus of relevance to rehabilitation.

Executive function and memory in relation to olfactory deficits in alcohol-dependent patients

BACKGROUND

Prior research indicates that chronic alcoholism is accompanied by olfactory deficits. These have been suggested to reflect dysfunctions in olfactory brain regions. The present study investigated the role of neurocognitive functioning in tests (executive function and memory) sensitive to the functional integrity of brain areas that are crucial to olfactory processing in patients with alcohol dependence.

METHODS

Performance on olfactory functions (detection threshold, quality discrimination, identification), executive function (Wisconsin Card Sorting Test), and memory (German version of the California Verbal Learning Test) was assessed in 32 alcohol-dependent patients and 30 healthy comparison subjects, comparable in age, gender, and smoking status.

RESULTS

Compared with controls, alcohol-dependent patients were impaired in all 3 domains, olfactory functions, executive function, and memory. In patients, olfactory discrimination ability was positively correlated with executive function performance. Regression analyses conducted to clarify the relation between group (patients vs controls), executive function, memory, and olfactory functions indicated that group was the only significant predictor of olfactory detection threshold and identification, and both group and executive function were found to be the significant predictors of olfactory discrimination.

CONCLUSIONS

Olfactory deficits in alcohol dependence appear to be associated with prefrontal cognitive dysfunction. Results indicate that olfactory quality discrimination deficits are related to executive function impairment. These findings add to the available research on frontal lobe dysfunction in alcoholism, suggesting that alcohol-related olfactory discrimination deficits may be associated with impairment in the functional integrity of the prefrontal lobe.

Effects of chronic alcohol dependence and chronic cigarette smoking on cerebral perfusion: a preliminary magnetic resonance study

BACKGROUND

Although approximately 80% of individuals with alcohol use disorders are chronic smokers and despite reported associations between chronic cigarette smoking and lower cerebral perfusion in nonalcoholics, previous brain perfusion studies with alcoholics did not account for the potential effects of concurrent chronic cigarette smoking.

METHODS

One-week-abstinent alcohol-dependent individuals in treatment (ALC) [19 smokers (sALC) and 10 nonsmokers (nsALC)] and 19 healthy light drinking, nonsmoking control participants (nsLD) were scanned with a pulsed arterial spin labeling method to measure cerebral perfusion without an exogenous contrast agent. Studies were performed with 2 different postlabeling delay times (time from labeling pulse to the excitation pulse; PLD=1,500 ms and PLD=1,200 ms) to assess the potential effect of arterial blood transit time on the perfusion. Average gray matter (GM) and white matter (WM) perfusion for the frontal and parietal lobes were calculated for each hemisphere from voxels containing at least 90% GM and 100% WM.

RESULTS

At PLD=1,500 ms, multivariate analyses compared ALC (combined sALC and nsALC) with nsLD (p=0.04) and contrasted sALC, nsALC, and nsLD (p=0.006). ALC, as a group, showed 13% lower frontal GM perfusion (p=0.005) and 8% lower parietal GM perfusion than nsLD (p=0.03). With ALC separated into smokers and nonsmokers, sALC showed 19% lower frontal GM perfusion (p=0.001) and 12% lower parietal GM perfusion than nsLD (p=0.004). In sALC, a higher number of cigarettes smoked per day was associated with lower perfusion. Overall, regional perfusion did not differ significantly between nsALC and nsLD. Results obtained with PLD=1,200 ms generally confirmed the 1,500 ms findings.

CONCLUSIONS

This study provides preliminary evidence that chronic cigarette smoking adversely affects cerebral perfusion in frontal and parietal GM of 1-week-abstinent alcohol-dependent individuals. These results are in line with our spectroscopic and structural magnetic resonance studies that suggest chronic cigarette smoking compounds the detrimental effects of alcohol dependence on brain neurobiology.

A comparison of neurocognitive function in nonsmoking and chronically smoking short-term abstinent alcoholics

Approximately 70-90% of individuals in North America seeking treatment for alcoholism are chronic smokers. A growing body of evidence suggests chronic cigarette smoking alone adversely affects neurocognition in adults. However, few studies on the neurocognitive function of short-term abstinent alcoholics have specifically considered the potential effects of chronic cigarette smoking. In this study, 20 nonsmoking recovering alcoholics (nsRA) and 22 actively smoking recovering alcoholics (sRA) participants, matched on age and education, were contrasted on a comprehensive neurocognitive battery after 34+/-9 days of abstinence. nsRA were superior to sRA on measures of auditory-verbal learning and memory, processing speed, cognitive efficiency, and static postural stability. These group differences were not a function of group disparities in age, education, estimated premorbid verbal intelligence, lifetime alcohol consumption, or other measured comorbid psychiatric or medical factors. In sRA, longer smoking duration was negatively correlated with executive skills, visuospatial learning, general cognitive efficiency, and static postural stability. These results indicate that greater consideration of the potential neurobiological effects of current chronic smoking on neurocognitive functioning is warranted in studies of alcoholism and other conditions where smoking is a common comorbid factor.

Geriatric alcoholism

BACKGROUND

The authors reviewed the clinical features, epidemiology, diagnosis, medical treatment, orofacial findings and dental treatment of geriatric patients with alcoholism.

TYPES OF STUDIES REVIEWED

The authors conducted MEDLINE searches for the period 1995 through 2004 using the terms "alcoholism," "geriatric," "pathophysiology," "treatment" and "dentistry." They selected reports published in English in peer-reviewed journals for further review.

RESULTS

Physiological changes associated with aging permit the harmful effects of drinking alcohol to arise at lower levels of consumption than in younger people. Excessive use of alcohol exacerbates the medical and emotional problems associated with aging and predisposes the person to adverse drug reactions with medications controlling these illnesses.

CLINICAL IMPLICATIONS

The incidence of dental disease in this population is extensive because of diminished salivary flow and a disinterest in performing appropriate oral hygiene techniques. Concurrent abuse of tobacco products worsens dental disease and heightens the risk of developing oral cancer. Identification of patients who abuse alcohol, a cancer-screening examination, preventive dental education, and use of saliva substitutes and anticaries agents are indicated. Clinicians must take precautions when performing surgery and when prescribing or administering analgesics, antibiotics or sedative agents that are likely to have an adverse interaction with alcohol.

Cerebral blood flow velocity and erythrocyte deformability in heavy alcohol drinkers at the acute stage and two weeks after withdrawal

OBJECTIVE

The aim of the study was to measure changes in blood flow velocity (V(mean)) and erythrocyte deformability (ED) in heavy alcohol drinkers after withdrawal and the relationship between them.

METHODS

The subjects were 32 heavy alcohol drinkers, mean age 47 years (22 men and 10 women). V(mean) was determined by a transcranial 2 MHz pulsed Doppler probe. ED was estimated by the method of cation-osmotic haemolysis (COH). The results were compared with those for 20 healthy volunteers.

RESULTS

The study revealed a significant decrease in V(mean) and ED after admission. V(mean) in the left middle cerebral artery (MCA) was 45.1+/-10.2 cm/s as compared with 59.1+/-7.5 cm/s in controls; in the right MCA, it was 46.8+/-11.3 cm/s as compared with 59.0+/-7.6 cm/s in controls (p < 0.001 in each case). But while V(mean) was significantly increased after 14 days withdrawal (54.4+/-10.4 cm/s in the left MCA, p < 0.001, and 54.3+/-12.1 cm/s in the right MCA, p < 0.01), ED showed only small change. A significant difference between V(mean) in men and women was found.

CONCLUSION

The changes in V(mean) after withdrawal are more influenced by plasma composition than by changes in ED.

Outcome from mild traumatic brain injury

PURPOSE OF REVIEW

The focus of this review is outcome from mild traumatic brain injury. Recent literature relating to pathophysiology, neuropsychological outcome, and the persistent postconcussion syndrome will be integrated into the existing literature.

RECENT FINDINGS

The MTBI literature is enormous, complex, methodologically flawed, and controversial. There have been dozens of studies relating to pathophysiology, neuropsychological outcome, and the postconcussion syndrome during the past year. Two major reviews have been published. Some of the most interesting prospective research has been done with athletes.

SUMMARY

The cognitive and neurobehavioral sequelae are self-limiting and reasonably predictable. Mild traumatic brain injuries are characterized by immediate physiological changes conceptualized as a multilayered neurometabolic cascade in which affected cells typically recover, although under certain circumstances a small number might degenerate and die. The primary pathophysiologies include ionic shifts, abnormal energy metabolism, diminished cerebral blood flow, and impaired neurotransmission. During the first week after injury the brain undergoes a dynamic restorative process. Athletes typically return to pre-injury functioning (assessed using symptom ratings or brief neuropsychological measures) within 2-14 days. Trauma patients usually take longer to return to their pre-injury functioning. In these patients recovery can be incomplete and can be complicated by preexisting psychiatric or substance abuse problems, poor general health, concurrent orthopedic injuries, or comorbid problems (e.g. chronic pain, depression, substance abuse, life stress, unemployment, and protracted litigation).

Chronic effects of social drinking in a card-sorting task: an event related potential study

OBJECTIVE

The Wisconsin Card Sorting Task (WCST) is one of the most widely used neuropsychological tests of frontal lobe function, which is thought to be affected by regular alcohol use. The present study used a computer-adapted version of the WCST to assess the effects of chronic alcohol consumption on the brain.

METHODS

Participants (N=59) sorted cards according to an initially unknown sorting rule, which referred to shape, number, or color. The correctness of the chosen sorting rule was indicated by a feedback stimulus. This correct sorting rule had to be followed for a number of stimuli, and when it changed participants had to find out which rule had to be followed next. A distinction was made between early (correct sorting rule is unknown) and late trials (correct sorting rule is known and applied). To measure brain activity related during the task event related potentials (ERPs) were recorded to the target and feedback stimulus in light (N=14), moderate (N=16) and heavy (N=19) social drinkers and excessive alcohol users (N=10).

RESULTS

No differences in number of series completed or the reaction time in each trial, were found between the four groups. In contrast, a mid-frontal N1 component in reaction to the feedback stimuli did reveal differences between the four groups. In the light and moderate drinkers, on early feedback trials the N1 was larger relative to late feedback trials, but this effect was absent in the heavy social drinkers and excessive drinkers.

CONCLUSIONS

The reduced N1 effect with increasing alcohol intake could reflect abnormal allocation of attention or impaired conflict monitoring, possibly based on activity in the anterior cingulate cortex.

SIGNIFICANCE

Heavy social drinking and excessive drinking leads to changes in the mid-frontal N1 during feedback trials of the WCST.

Executive Functioning Early in Abstinence From Alcohol

BACKGROUND

Executive dysfunction is among the cognitive impairments that may persist after abstinence in alcohol-dependent persons. The type(s) and extent of executive dysfunction early in abstinence have not been well characterized, but they may have important implications for the evolution of behavioral treatment strategies.

METHODS

To determine which aspects of executive functioning were impaired in early abstinence, we administered memory and executive function tests to veterans who successively presented for treatment at an outpatient substance abuse clinic. We then compared the neuropsychological performance of these recovering alcoholics (n = 27) with that of age-matched primary care outpatients (n = 18). We also examined group differences in self-evaluation of cognitive decline and evaluated associations between drinking history and cognitive impairment in the index group.

RESULTS

We found that the normal and alcohol-dependent groups differed on abstract reasoning, memory discrimination, and effectiveness on timed tasks. Patients in the alcohol-dependent sample were also more likely to perceive themselves as cognitively impaired. It is interesting to note that the duration of alcohol use did not relate to neuropsychological test performance, but recent quantity consumed and days of sobriety were associated with nonverbal abstract reasoning ability.

CONCLUSIONS

Executive functions are impaired early in abstinence and should, therefore, be taken into account when early behavioral treatments are being developed.