Cognitive components of frontal lobe function in alcoholics classified according to Lesch's typology

Frontal assessment battery: A tool for screening minimal hepatic encephalopathy?

AIM

To apply the Frontal Assessment Battery to cirrhotic patients with or without overt hepatic encephalopathy (OHE) and controls.

METHODS

The frontal assessment battery (FAB) was applied to 87 patients with liver cirrhosis (16 with and 71 without OHE) and 40 control subjects without cirrhosis treated at the alcohol and liver outpatient clinics and the gastroenterology ward of the Cassiano Antônio de Moraes University Hospital (Hospital Universitário Cassiano Antônio de Moraes - HUCAM), Espírito Santo, Brazil.

RESULTS

The average FAB score was lower for the cirrhotic than for the non-cirrhotic patients (10.6 ± 3.67 vs 12.25 ± 2.72, P = 0.015). The FAB score was lower for the cirrhotic patients with OHE than for the patients without OHE (8.25 ± 4.55 vs 11.14 ± 3.25, P = 0.027). The total FAB score was lower for the cirrhotic patients without OHE than for the non-cirrhotic patients, although this difference was not significant (11.14 ± 3.25 vs 12.25 ± 2.72, P = 0.067). Nevertheless, the difference in the scores on the subtest that assessed the ability to inhibit a response previously conditioned to a stimulus was significant (1.72 ± 0.93 vs 2.2 ± 0.85, P = 0.011).

CONCLUSION

The present study indicates that the FAB is a promising tool for outpatient minimal HE screening and the assessment of HE severity.

Relations Between Cognitive Abilities, Drinking Characteristics, and Emotional Recognition in Alcohol Dependence: A Preliminary Exploration

BACKGROUND

Alcohol dependence is characterized by wide-ranging cognitive impairments, but also by emotional facial expressions (EFEs) recognition deficits. Although they play a crucial role both in the development and in the maintenance of the disease, cognitive and emotional disorders have up to now been mostly explored separately. As a result, not much is known regarding their interactions. This study thus aims at exploring the relations between cognition and emotion in alcohol dependence, and more specifically between cognitive performance, drinking characteristics, and EFE recognition.

METHODS

About 26 recently detoxified alcohol-dependent individuals and 26 matched controls were tested for cognitive abilities (by means of a standardized neuropsychological battery) and for EFE recognition.

RESULTS

Alcohol-dependent individuals simultaneously presented altered performances for executive abilities and EFE recognition (particularly for disgust recognition). Moreover, a regression analysis showed that EFE performance was centrally related to episodic memory and cognitive flexibility.

CONCLUSIONS

These results clarify the relations between EFE recognition, cognitive abilities, and drinking characteristics in alcohol dependence and clearly suggest that cognitive factors should be taken into account in future studies exploring emotional processes in alcohol dependence. Specific cognitive programs should be developed to rehabilitate cognitive and emotional abilities simultaneously.

Multidimensional alcoholism typologies: could they guide clinical practice? Results from a 3-month prospective study

OBJECTIVE

The current nosological classifications may describe a syndrome of "alcoholism" that is too heterogeneous to produce prognostic models for clinical management. Multidimensional alcoholism typologies (ATs) could represent a valuable paradigm in the search for targeted treatment. The main goal of this study was to evaluate the clinical implications of 3 empirically-validated ATs, focusing on various measures of clinical performance.

METHOD

This was a 3-month naturalistic study in which drinking status, and participation in the clinical protocol and group psychotherapy were recorded and used as indicators of treatment performance. The clinical profiles of the subtypes were also compared and graphically presented. Alcohol-dependent outpatients were classified according to the Cloninger, Lesch, and NETER typologies.

RESULTS

The results showed that the type II (Cloninger), type IV (Lesch), and sociopathic and addictopathic (NETER) subgroups showed a worse outcome in terms of abstinence rates and clinical healthcare resource use.

CONCLUSIONS

Our findings point to the need to differentiate multidimensional alcoholism subtypes before planning the clinical management of alcohol use disorders.

Pharmacological management of alcohol dependence: from mono-therapy to pharmacogenetics and beyond

Almost 10% of the world's population is affected by alcohol use disorders, and the treatment of alcohol dependence (AD) still remains a challenge. Patients with AD can differ in many traits. Three drugs (disulfiram, naltrexone, and acamprosate) have been approved by the FDA for the treatment of AD, and in some European countries sodium oxybate is also approved for this purpose. Combined pharmacological therapy has not provided such convincing results. Considering the fact that the "ideal" and effective drug for all types of alcoholic patients does not exists, the future challenge will be to identify a personalized approach. Recent data has shown that this objective can be achieved by investigating the genetic variability of the patient. Moreover, the use of replacement molecules can probably be considered an advantageous therapeutic opportunity (i.e. sodium oxybate). In addition, reduction of alcohol consumption is increasingly accepted as a viable treatment goal, and the use of nalmefene "as-needed" (a pharmacological approach similar to naltrexone, but, possibly, with lower hepatotoxicity) may help in the treatment of AD. Thus, it is important to stress that a pharmacological approach to treat AD should be preceded by the definition of patient characteristics; this may help in the choice of the most appropriate drug and it can be done more easily when more pharmacological options approved for the treatment of AD are also available.

Sodium oxybate in maintaining alcohol abstinence in alcoholic patients according to Lesch typologies: a pilot study

Sodium oxybate (SO) is a γ-amino-butyric acid (GABA)-ergic drug currently used for the treatment of alcohol dependence (AD) in some European countries. The aim of this study was to describe the effect of SO administration in alcoholics classified according to Lesch alcoholism typology (LAT). Forty-eight patients were enrolled and classified into four groups according to LAT. All patients were treated with oral SO (50 mg/kg of body weight t.i.d.) for 12 weeks. All patients significantly reduced their alcohol intake (p<0.001). Alcohol abstinence during the 12 weeks of treatment did not differ between the four groups at the end of treatment. Craving for SO did not significantly differ amongst groups; cases of SO abuse were very limited and were observed in almost 10% of patients. In conclusion, our study showed an overall efficacy of SO in the treatment of AD irrespective of LAT categories. However, our results confirm that alcoholics with psychiatric co-morbidity, particularly with a borderline personality disorder of Axis II, are at a greater risk of developing craving for and abuse of the drug: until craving for alcohol and craving for SO are characterized in depth, SO should be used with caution in these patients.

Gray matter volume in left rostral middle frontal and left cerebellar cortices predicts frontal executive performance in alcoholic subjects

BACKGROUND

Alcoholic subjects manifest important deficits in frontal executive function, yet maintain cognitive mental status within normal range.

METHODS

This study searched for volumetric measurements of segmented brain structures obtained from magnetic resonance imaging (MRI) that would predict executive functions and cognitive mental status in alcoholic subjects. The frontal assessment battery (FAB) and the Mini-Mental State Examination (MMSE) were applied to alcoholic subjects who underwent MRI. Cortical and subcortical segmentation and corrections were performed using FreeSurfer. Multiple linear regressions analyses having volumetric measures of segmented brain structures as predictors for FAB or MMSE scores as dependent measures were conducted. Sixty alcoholic subjects, 52 males, mean age of 47.2 ± SD 10.4 years, with heavy use of alcohol (mean 284.4 ± SD 275.9 g of alcohol/d) over a long time (mean 32.4 ± SD 11.1 years), showed FAB 11.1 ± SD 3.2 and MMSE of 25.2 ± SD 4.1.

RESULTS

Multiple regression analyses having left and right side of each segment as predictors showed that gray matter volumes of rostral middle frontal cortex and cerebellar cortex (p < 0.001), in which only the left side of these structures showed significant partial effects in the full model (p < 0.05), showed to predict FAB performance. They were even more predictive when considered together (p < 0.001), in which both left rostral middle frontal cortex (p < 0.05) and left cerebellar cortex (p < 0.01) predictors had significant partial effects in the full model. None of brain structures was predictive of MMSE performance.

CONCLUSIONS

We have concluded that volumetric measurements of left rostral middle frontal and cerebellar cortices seem to be able to predict the frontal executive performance but not the cognitive mental status in alcoholic subjects.

Fluctuating disinhibition: implications for the understanding and treatment of alcohol and other substance use disorders

Disinhibition is present in various maladaptive behaviors, including substance use disorders. Most previous research has assumed that disinhibition is a psychological construct that is relatively stable within individuals. However, recent evidence suggests that the ability to inhibit behavior fluctuates in response to environmental and psychological triggers. In this review we discuss some of the factors that cause (dis)inhibition to fluctuate, we examine whether these fluctuations contribute to subjective craving and substance consumption, and we ask if they might increase the risk of relapse in those who are attempting to abstain. The research that we discuss has furthered our understanding of the causal relationships between disinhibition and substance use disorders, and it also highlights opportunities to develop novel treatment interventions. We conclude that substance misusers and their therapists should be made aware of the triggers that can cause disinhibition to fluctuate, and we highlight the need for more research to investigate the effectiveness of inhibitory control training in clinical settings.

Response inhibition toward alcohol-related cues using an alcohol go/no-go task in problem and non-problem drinkers

BACKGROUND

Previous results suggested that alcohol abusers and alcohol dependent patients show cognitive biases in the treatment of alcohol-related cues, especially approach and inhibition deficit biases. Response inhibition was often tested using the go/no-go task in which the participants had to respond as quickly as possible to a class of stimuli (go stimuli) while refraining from responding to another class of stimuli (no-go stimuli). Previous studies assessing specific response inhibition deficits in the process of alcohol-related cues obtained conflicting results. The aims of the present study were to clarify response inhibition for alcohol cues in problem and non-problem drinkers, male and female and to test the effect of alcohol brand logos.

METHODS

Thirty-six non-problem drinker and thirty-five problem drinker undergraduate students completed a modified alcohol go/no-go task using alcohol and neutral object pictures, with or without brand logos, as stimuli. An additional control experiment was carried out to check whether participants' awareness that the study tested their response to alcohol might have biased the results.

RESULTS

All participants, whether problem or non-problem drinkers, showed significantly shorter mean reaction times when alcohol pictures are used as go stimuli and significantly higher percentages of commission errors (false alarms) when alcohol pictures are used as no-go stimuli. Identical effects were obtained in the control experiment when participants were unaware that the study focused on alcohol. Shorter reaction times to alcohol-related cues were observed in problem drinkers relative to non-problem drinkers but only in the experimental condition with no brand logos on alcohol pictures. The addition of alcohol brand logos further reduced reaction times in light drinkers, thereby masking group differences. There was a tendency for female problem drinkers to show higher rates of false alarms for alcohol no-go stimuli, although this effect was only very close to statistical significance.

CONCLUSIONS

All participants exhibited a cognitive bias in the treatment of alcohol cues that might be related to the positive emotional value of such alcohol-related cues. Stronger cognitive biases in the treatment of alcohol cues were observed in problem drinkers, although differences between problem and non-problem drinkers were relatively small-scale and required specific experimental parameters to be uncovered. In particular, the presence of alcohol brand logos on visual alcohol cues was an important experimental parameter that significantly affected behavioral responses to such stimuli.

Behavioral effects of transcranial direct current stimulation (tDCS) induced dorsolateral prefrontal cortex plasticity in alcohol dependence

Transcranial Direct Current Stimulation (tDCS) has been shown to reduce acute substance craving in drug addicts, and improve cognition in neuropsychiatric patients. Here we aimed to explore further tDCS induced behavioral and neurophysiological modulation including assessment of relapse rate over a prolonged time course in alcoholism. We examined the effects of repeated anodal tDCS (2mA, 35 cm(2), 20min) over the left dorsolateral prefrontal cortex (DLPFC) on relapse to the use of alcohol in alcoholics from outpatient services, who received additional routine clinical treatment. Furthermore, event related potentials (ERPs), cognitive and frontal executive processes, craving, depressive and anxiety symptoms were obtained before and after treatment. From thirteen alcoholic subjects, seven were randomized to sham-tDCS and six to real tDCS treatment (once a week for five consecutive weeks). Depressive symptoms and craving were reduced to a larger extent in the tDCS group compared to the sham group (p=0.005 and p=0.015, respectively). On the other hand, active tDCS was able to block the increase in neural activation triggered by alcohol related and neutral cues in prefrontal cortex (PFC) as indexed by ERP as seen in the sham-tDCS group. Finally, there was a trend for increased change in executive function in the tDCS group compared to the sham-tDCS group (p=0.082), and, similarly, a trend for more relapses in the tDCS group compared to sham tDCS (four alcoholic subjects (66.7%) vs. one (14.3%), p=0.053).These results confirm the previous findings of tDCS effects on craving in alcoholism and also extend these findings as we showed also tDCS-related mood improvement. However, potential increase in relapse is possible; thus the clinical value of an increase in craving and improvement in depression and executive function needs to be carefully assessed in further studies; including investigation of optimal parameters of stimulation.

Auditory event-related potentials (P3) and cognitive changes induced by frontal direct current stimulation in alcoholics according to Lesch alcoholism typology

Frontal lobe dysfunction is a hallmark of alcohol dependence. Recent studies have shown that a simple but powerful technique of cortical modulation--transcranial direct current stimulation (tDCS)--can induce significant cognitive changes. We therefore aimed to assess the clinical and electrophysiological (as indexed by P3) effects of tDCS of left dorsolateral prefrontal cortex (DLPFC) in different types of alcoholic patients according to Lesch's typology. We enrolled 49 alcoholic subjects, aged between 18 and 75 yr, during the subacute abstinence period to participate in this study. Subjects underwent event-related potential (ERP) registration of alcohol-related and neutral sounds before, during and after active tDCS (1 mA, 35 cm², during 10 min) or sham procedure in a counterbalanced and randomized order. Frontal assessment battery (FAB) and five items of the Obsessive Compulsive Drinking Scale were applied at the beginning and at the end of each experimental session. ERP analysis showed an increase in the mean amplitude of P3 associated with alcohol-related sounds after tDCS. This effect was not seen for neutral sounds. This change was more pronounced in Lesch IV alcoholics. Secondary exploratory analysis showed a significant improvement of FAB performance after active tDCS compared to sham tDCS in Lesch IV alcoholics only. We showed clinical and electrophysiological evidence of tDCS-induced frontal activity enhancement that was specific for Lesch IV alcoholics. Given that frontal dysfunction may contribute to the loss of control over drinking behaviour, local increase in frontal activity induced by tDCS might have a beneficial clinical impact in the future.

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.