Event-related potentials during visual target detection in treatment-naïve active alcoholics

The Association of P300 Components With Clinical Characteristics and Efficacy of Pharmacotherapy in Alcohol Use Disorder

PURPOSE

The purpose of this study is to explore the association of P300 components with clinical characteristics and efficacy of pharmacotherapy in alcohol use disorder (AUD).

METHODS

One hundred fifty-one AUD patients and 96 healthy controls were recruited and evaluated for the symptoms of depression, anxiety, sleep, and cognitive function by the Alcohol Use Disorders Identification Test (AUDIT), the 9-item Patient Health Questionnaire (PHQ-9), the 7-item Generalized Anxiety Disorder scale (GAD-7), the Pittsburgh Sleep Quality Index (PSQI), Digit Symbol Substitution test (DSST), and event-related potential P300, which is one of the averaged scalp electroencephalography responses time-locked to specific events. Among the AUD group, 101 patients finished an 8-week pharmacotherapy and were evaluated for the above data at post-intervention.

RESULTS

1. At baseline, AUD patients had higher scores of AUDIT, PHQ-9, GAD-7, PSQI, and P300 latency at Cz, Pz, and Fz and lower DSST score and smaller P300 amplitudes at Fz, Cz, and Pz compared with controls. P300 components correlated significantly with alcohol dose and score of AUDIT, PHQ-9, GAD-7, PSQI, and DSST. 2. After 8 weeks' treatment, there were significant changes for the P300 components; alcohol dose; and score of AUDIT, PHQ-9, GAD-7, PSQI, and DSST. Variables at baseline, including P300 amplitudes at Fz, Cz, and Pz; latency of Fz and Pz; alcohol dose; and scores of PHQ-9, GAD-7, PSQI, and DSST, were significantly associated with changes of reduction rate of AUDIT scores. However, P300 amplitudes at Fz, Cz, and Pz in AUD patients after 8-week treatment were still significantly shorter than healthy controls (HCs), and P300 latencies at Fz, Cz, and Pz were significantly longer than HCs. 3. When validated area under the receiver operating characteristic curve (AUC) was over 0.80, the baseline variables including amplitudes at Cz and Pz, alcohol dose, and scores of PSQI could predict the changes of reduction rate of AUDIT score.

CONCLUSION

P300 amplitudes and latencies at Fz, Cz, and Pz could be used as biological markers for evaluating the clinical characters and severity of AUD. P300 amplitudes at Cz and Pz, sleep condition, and cognitive function at baseline could predict the efficacy of pharmacotherapy for AUD patients.

ADHD: Reviewing the Causes and Evaluating Solutions

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder in which patients present inattention, hyperactivity, and impulsivity. The etiology of this condition is diverse, including environmental factors and the presence of variants of some genes. However, a great diversity exists among patients regarding the presence of these ADHD-associated factors. Moreover, there are variations in the reported neurophysiological correlates of ADHD. ADHD is often treated pharmacologically, producing an improvement in symptomatology, albeit there are patients who are refractory to the main pharmacological treatments or present side effects to these drugs, highlighting the importance of developing other therapeutic options. Different non-pharmacological treatments are in this review addressed, finding diverse results regarding efficacy. Altogether, ADHD is associated with different etiologies, all of them producing changes in brain development, leading to the characteristic symptomatology of this condition. Given the heterogeneous etiology of ADHD, discussion is presented about the convenience of personalizing ADHD treatment, whether pharmacological or non-pharmacological, to reach an optimum effect in the majority of patients. Approaches to personalizing both pharmacological therapy and neurofeedback are presented.

Persistence of Neuronal Alterations in Alcohol-Dependent Patients at Conclusion of the Gold Standard Withdrawal Treatment: Evidence From ERPs

Background: One of the main challenges for clinicians is to ensure that alcohol withdrawal treatment is the most effective possible after discharge. To address this issue, we designed a pilot study to investigate the efficacy of the rehabilitation treatment on the main stages of information processing, using an electroencephalographic method. This topic is of main importance as relapse rates after alcohol withdrawal treatment remain very high, indicating that established treatment methods are not fully effective in all patients in the long run. Method: We examined in alcohol-dependent patients (ADP) the effects of the benzodiazepine-based standard detoxification program on event-related potential components at incoming (D0) and completion (D15) of the treatment, using tasks of increasing difficulty (with and without workload) during an auditory oddball target paradigm. Untreated non-alcohol-dependent-volunteers were used as matching controls. Results: At D0, ADP displayed significantly lower amplitude for all ERP components in both tasks, as compared to controls. At D15, this difference disappeared for the amplitude of the N1 component during the workload-free task, as well as the amplitude of the P3b for both tasks. Meanwhile, the amplitude of the N2 remained lower in both tasks for ADP. At D0, latencies of N2 and P3b in both task conditions were longer in ADP, as compared to controls, whilst the latency of N1 was unchanged. At D15, the N2 latency remained longer for the workload condition only, whereas the P3b latency remained longer for the workload-free task only. Conclusion: The present pilot results provide evidence for a persistence of impaired parameters of ERP components, especially the N2 component. This suggests that neural networks related to attention processing remain dysfunctional. Longitudinal long-term follow-up of these patients is mandatory for further assessment of a link between ERP alterations and a later risk of relapse.

Cognitive Control Deficits in Alcohol Dependence Are a Trait- and State-Dependent Biomarker: An ERP Study

Alcohol dependence (AD) presents cognitive control deficits. Event-related potential (ERP) P300 reflects cognitive control-related processing. The aim of this study was to investigate whether cognitive control deficits are a trait biomarker or a state biomarker in AD. Participants included 30 AD patients and 30 healthy controls (HCs). All participants were measured with P300 evoked by a three-stimulus auditory oddball paradigm at a normal state (time 1, i.e., just after the last alcohol intake) and abstinence (time 2, i.e., just after a 4-week abstinence). The results showed that for P3a and P3b amplitude, the interaction effect for group × time point was significant, the simple effect for group at time 1 level and time 2 level was significant, and the simple effect for time point at AD group level was significant; however, the simple effect for time point at HC group level was not significant. Above results indicated that compared to HCs, AD patients present reductions of P3a/3b amplitude, and after 4-week alcohol abstinence, although P3a/3b amplitudes were improved, they were still lower than those of HCs. For P3a and P3b latencies, no significant differences were observed. These findings conclude that AD patients present cognitive control deficits that are reflected by P3a/3b and that cognitive control deficits in AD are trait- and state-dependent. The implication of these findings is helpful to understand the psychological and neural processes for AD, and these findings suggest that improving the cognitive control function may impact the treatment effect for AD.

Exploring individual and group differences in latent brain networks using cross-validated simultaneous component analysis

Component models such as PCA and ICA are often used to reduce neuroimaging data into a smaller number of components, which are thought to reflect latent brain networks. When data from multiple subjects are available, the components are typically estimated simultaneously (i.e., for all subjects combined) using either tensor ICA or group ICA. As we demonstrate in this paper, neither of these approaches is ideal if one hopes to find latent brain networks that cross-validate to new samples of data. Specifically, we note that the tensor ICA model is too rigid to capture real-world heterogeneity in the component time courses, whereas the group ICA approach is too flexible to uniquely identify latent brain networks. For multi-subject component analysis, we recommend comparing a hierarchy of simultaneous component analysis (SCA) models. Our proposed model hierarchy includes a flexible variant of the SCA framework (the Parafac2 model), which is able to both (i) model heterogeneity in the component time courses, and (ii) uniquely identify latent brain networks. Furthermore, we propose cross-validation methods to tune the relevant model parameters, which reduces the potential of over-fitting the observed data. Using simulated and real data examples, we demonstrate the benefits of the proposed approach for finding credible components that reveal interpretable individual and group differences in latent brain networks.

Impact of Spectral Severity of Alcoholism on Visual-Evoked Potentials: A Neuropsychiatric Perspective

Background:

The deleterious effects of alcohol on the brain are replete in literature. Only a few neurophysiologic measures can pick up the neuronal dysfunctions, one of them being visual-evoked potential (VEP). A very limited amount of data exists on the progression of neural abnormalities related to the spectral severity of alcoholism.

Aim of the Study:

To evaluate the impact of spectral severity of alcoholism through VEP and to understand the emergence of any specific pattern or morphometric abnormalities related to alcohol-induced neuropsychiatric presentations.

Methodology:

A total of 90 cases were recruited in addition to 180 age- and sex-matched controls using purposive and random sampling. The Structured Clinical Interview for DSM-IV Axis I Disorders, Clinician Version and Campbell Neuropsychiatric Inventory were used to evaluate alcohol disorders and its neuropsychiatric complications apart from the mandatory consultant-specific clinical evaluations of all the cases. Of 90 cases of alcohol dependence, 15 patients were currently abstinent for >6 months, 15 had alcohol intoxication, 15 had signs of alcohol withdrawal, 15 had physical complications, 15 had psychiatric comorbidity, and 15 had neurological complications such as epilepsy. VEP recordings were taken using an Evoked Potential Recorder (RMS EMG. EP MARK II) where the stimulus configuration consisted of transient pattern-reversal method in which a black and white checkerboard was generated full field.

Results:

Mean age of cases was 37.71 ± 11.49 years compared to 39.43 ± 10.67 years in controls (range 18–65 years). VEP abnormalities comprising of prolonged latencies (62.5%) with a statistically significant difference (P < 0.001) from the healthy controls was observed in cases of alcohol withdrawal syndrome. Predominant amplitude reduction with normal latency was obtained in 37.5% cases of withdrawal. Severe VEP abnormalities, i.e., both latency delay and amplitude reduction, were found in 75% patients with psychiatric comorbidity, 66.67% patients with neurological complications, i.e., epilepsy, and 33.34% patients with physical complications. An explicit finding of prominent interocular differences was a prominent feature present in 25% of patients with complications.

Differential impairments across attentional networks in binge drinking

RATIONALE

The cognitive deficits observed in young binge drinkers have been largely documented during the last decade. Yet, these earlier studies have mainly focused on high-level cognitive abilities (particularly memory and executive functions), and uncertainty thus still abounds regarding the integrity of less complex cognitive processes in binge drinking. This is particularly true for attentional abilities, which play a crucial role in behavior regulation and are impaired in other alcohol-related disorders.

OBJECTIVES AND METHODS

To specify the attentional deficits associated with binge drinking, two groups of university students (40 binge drinkers and 40 matched controls) performed the Attention Network Task, a theoretically grounded test assessing three independent attentional networks: alerting, orienting, and executive control.

RESULTS

Binge drinkers displayed preserved orienting performance but impaired alerting and executive control. Binge drinking is thus not related to a general attentional impairment but rather to specific impairments of the alerting and executive control networks.

CONCLUSIONS

These results underline that, beyond the already explored high-level deficits, binge drinking is also related to impairments for attentional abilities. In view of the role played by attentional impairments in alcohol dependence, the present data also suggest that rehabilitation programs should be developed to improve attentional abilities at the early stages of alcohol-related disorders.

Reward processing deficits and impulsivity in high-risk offspring of alcoholics: A study of event-related potentials during a monetary gambling task

BACKGROUND

Individuals at high risk to develop alcoholism often manifest neurocognitive deficits as well as increased impulsivity. The goal of the present study is to elucidate reward processing deficits, externalizing disorders, and impulsivity as elicited by electrophysiological, clinical and behavioral measures in subjects at high risk for alcoholism from families densely affected by alcoholism in the context of brain maturation across age groups and gender.

METHODS

Event-related potentials (ERPs) and current source density (CSD) during a monetary gambling task (MGT) were measured in 12-25 year old offspring (N=1864) of families in the Collaborative Study on the Genetics of Alcoholism (COGA) Prospective study; the high risk (HR, N=1569) subjects were from families densely affected with alcoholism and the low risk (LR, N=295) subjects were from community families. Externalizing disorders and impulsivity scores were also compared between LR and HR groups.

RESULTS

HR offspring from older (16-25 years) male and younger (12-15 years) female subgroups showed lower P3 amplitude than LR subjects. The amplitude decrement was most prominent in HR males during the loss condition. Overall, P3 amplitude increase at anterior sites and decrease at posterior areas were seen in older compared to younger subjects, suggesting frontalization during brain maturation. The HR subgroups also exhibited hypofrontality manifested as weaker CSD activity during both loss and gain conditions at frontal regions. Further, the HR subjects had higher impulsivity scores and increased prevalence of externalizing disorders. P3 amplitudes during the gain condition were negatively correlated with impulsivity scores.

CONCLUSIONS

Older male and younger female HR offspring, compared to their LR counterparts, manifested reward processing deficits as indexed by lower P3 amplitude and weaker CSD activity, along with higher prevalence of externalizing disorders and higher impulsivity scores.

SIGNIFICANCE

Reward related P3 is a valuable measure reflecting neurocognitive dysfunction in subjects at risk for alcoholism, as well as to characterize reward processing and brain maturation across gender and age group.

Risk for behavior problems in children of parents with substance use disorders

Using a high-risk community sample (N = 567), the current study examined risk for externalizing and internalizing problems in the children of parents with recovered and current substance use disorders (SUDs). This study also tested whether parenting mediated the relations between these variables. Results suggest that children of parents with current diagnoses were at elevated risk for externalizing and internalizing problems, but children of parents with recovered diagnoses were only at risk for externalizing problems. Perceived parental consistency of support mediated the relations between parent current SUD and child externalizing and internalizing problems. Disruption of the home environment may in part explain why children of parents with SUDs are at risk for externalizing and internalizing problems. However, even after parent SUD has remitted, children remain at risk for externalizing problems, suggesting multiple mechanisms by which parents confer risk for psychopathology.

Attentional alterations in alcohol dependence are underpinned by specific executive control deficits

BACKGROUND

Attentional biases and deficits play a central role in the development and maintenance of alcohol dependence, but the underlying attentional processes accounting for these deficits have been very little explored. Importantly, the differential alterations across the 3 attentional networks (alerting, orienting, and executive control) remain unclear in this pathology.

METHODS

Thirty recently detoxified alcohol-dependent individuals and 30 paired controls completed the Attention Network Test, which allow exploring the attentional alterations specifically related to the 3 attentional networks.

RESULTS

Alcohol-dependent individuals presented globally delayed reaction times compared to controls. More centrally, they showed a differential deficit across attention networks, with a preserved performance for alerting and orienting networks but impaired executive control (p < 0.001). This deficit was not related to psychopathological comorbidities but was positively correlated with the duration of alcohol-dependence habits, the number of previous detoxification treatments and the mean alcohol consumption before detoxification.

CONCLUSIONS

These results suggest that attentional alterations in alcohol dependence are centrally due to a specific alteration of executive control. Intervention programs focusing on executive components of attention should be promoted, and these results support the frontal lobe hypothesis.

Absence of P300 reduction in South African treatment-naïve adolescents with alcohol dependence

BACKGROUND

Event-related potential studies show reduced P300 amplitudes in alcohol use disorders (AUDs). Alcohol exposure, genetic vulnerability to alcoholism, and comorbid psychopathology may contribute to this reduction. Most previous research has studied treated adult AUD samples, which have more severe alcoholism, a greater family history of AUDs, and more comorbidity than untreated samples. Untreated AUD samples tend to have little or no P300 amplitude reduction. We compared P300 between treatment-naïve alcohol-dependent (TNAD) adolescents with no diagnosable substance abuse or psychiatric comorbidity and nonsubstance-abusing control (NSAC) adolescents.

METHODS

Individuals between the ages of 13 and 18 years were recruited into either TNAD (n = 45) or NSAC (n = 64) groups. Alcohol use variables, family history density of alcohol problems, and psychiatric symptom counts were assessed in a clinician-administered evaluation. EEGs were recorded during performance of a 3-condition visual target detection task.

RESULTS

P300 amplitudes were of comparable size in TNAD adolescents and NSAC adolescents. Boys demonstrated larger P3a and P3b amplitudes than girls. Within TNAD, P3b amplitude was reduced in those who drank more frequently, and P3a latency was more prolonged in subjects with higher internalizing symptom counts.

CONCLUSIONS

The P300 deficit was not present in TNAD adolescents without comorbidities. In comparison to results of reduced P300 in treated adolescent AUD samples, this finding likely reflects moderate alcohol exposure, lower genetic vulnerability to alcoholism, and lack of comorbidity in our sample. Further work is needed to determine the relative contributions of these factors to changes in the P300.

Theta event-related synchronization is a biomarker for a morbid effect of alcoholism on the brain that may partially resolve with extended abstinence

Analyzing the induced (non-stimulus-phase-locked) EEG activity elicited by targets in a three-condition visual oddball task, Fein and colleagues have shown increased theta band event-related synchronization (ERS) in two different samples of long-term abstinent alcoholics (LTAA) compared with age- and gender-comparable controls. The theta ERS effect in alcoholics was also shown to be independent of, and opposite in direction to, the reduced amplitude evoked (stimulus-phase-locked) activity typically found in alcoholics and those at genetic risk of developing alcoholism. This study extends these findings by applying time-frequency analysis to target stimulus event-related EEG to compare evoked and induced theta activity in 43 LTAA and 72 nonalcoholic controls with a group of 31 alcoholics who just recently initiated abstinence from alcohol (between 6- and 15-week abstinent; referred to as short-term abstinent alcoholics, STAA). Results demonstrated that (1) evoked theta power was reduced to the same degree in STAA and LTAA compared with nonalcoholic control participants, while (2) induced theta activity, measured by theta ERS, was increased in both STAA and LTAA relative to controls, but was also increased in STAA relative to LTAA. The STAA and LTAA groups did not differ on measures of alcohol use severity or family history of alcohol problems. These results, coupled with previous findings that show a relationship between stronger theta ERS and increased memory load and attention allocation, suggest that increased theta ERS may be a biomarker for a detrimental effect of chronic alcohol abuse on the brain - a detriment that may recover, at least partially, with extended abstinence.

Gait and balance in treatment-naïve active alcoholics with and without a lifetime drug codependence

BACKGROUND

Disturbed gait and balance are among the most consistent sequelae of chronic alcoholism. However, although a majority of alcoholics have never sought treatment, most investigations showing ataxia in alcohol-dependent individuals have relied on samples drawn from treated populations. In addition, few studies have addressed the associations of codependence on other drugs with alcoholic gait and balance disturbance.

METHODS

This study employed the Walk-a-Line Ataxia Battery (Fregly et al. Alcohol Clin Exp Res 1972;43:395-399) to assess gait and balance in treatment-naïve, actively drinking alcohol-dependent men and women (TNA; n = 69) who were dependent on alcohol only (ALC; n = 43), or who also had a lifetime drug dependence (ALC + DRG; n = 26; i.e., methamphetamine, cocaine, opiates, and/or marijuana), compared with nonsubstance abusing controls (NSAC; n = 74).We also examined associations between lifetime alcohol use and age with gait and balance measures.

RESULTS

Our main findings were (i) no evidence of disturbed gait and balance in ALC versus NSAC and (ii) significantly disturbed gait and balance in ALC + DRG, relative to both NSAC and ALC, along with steeper age-associated decline in gait and balance performance in ALC versus ALC + DRG.

CONCLUSIONS

Our results provide evidence consistent with previous studies that TNA (without a lifetime drug codependence) may represent a population that is different and less impaired (including in gait and balance) than treated alcoholics. Additionally, we provide evidence that ALC + DRG, with greater alcohol use and family drinking density than ALC, have an accelerated effect of age on gait and balance disturbance compared with both NSAC and ALC. The ALC + DRG group likely represents a subset of TNA with different characteristics than ALC.