Disruption of cerebellar-cortical functional connectivity predicts balance instability in alcohol use disorder

Contributions of Cerebral White Matter Hyperintensities to Postural Instability in Aging with and without Alcohol Use Disorder

BACKGROUND

Postural instability and brain white matter hyperintensities (WMH) are both noted markers of normal aging and alcohol use disorder (AUD). Here, we questioned what variables contribute to sway path/WMH relations in individuals with AUD and healthy control participants.

METHOD

The data comprised 404 balance platform sessions, yielding sway path length and MRI acquired cross-sectionally or longitudinally, in 102 control and 158 AUD participants, ages 25-80 years. Balance sessions were typically conducted on the same day as MRI FLAIR acquisitions, permitting WMH volume quantification. Factors considered in multiple regression analyses as potential contributors to relations between WMH volumes and postural instability were age, sex, socioeconomic status, education, pedal 2-point discrimination, systolic and diastolic blood pressure, body mass index, depressive symptoms, total alcohol consumed in the past year, and race.

RESULTS

Initial analysis identified diagnosis, age, sex, and race as significant contributors to observed sway path/WMH relations. Inclusion of these factors as predictors in multiple regression analysis substantially attenuated the sway/WMH relations in both AUD and healthy control groups. Women, irrespective of diagnosis or race, had shorter sway paths than men. Black participants, irrespective of diagnosis or sex, had shorter sway paths than non-Black participants despite having modestly larger WMH volumes than non-Black participants, possibly a reflection of the younger age of the Black sample.

DISCUSSION

Longer sway paths were related to larger WMH volumes in healthy men and women, with and without AUD. Critically, however, age nearly fully accounted for these relations.

The relationship between physical performance and alcohol consumption levels in Russian adults

Investigating the relationship between alcohol consumption and physical performance, we used data from the 2015-2018 Know Your Heart study on 4215 adults aged 35-69 from Arkhangelsk and Novosibirsk, Russia. We classified participants' drinking status into non-drinking, non-problem drinking, hazardous drinking, and harmful drinking based on their self-reported drinking behaviors. To evaluate physical performance, we developed a Composite Physical Performance Scale (CPPS), which combined the results of three functional tests: grip strength (GS), closed-eyes balance, and chair rises (CR). We applied multivariable linear regression to assess the relationship between alcohol consumption and CPPS score, and ordinal logistic regression to explore the associations between alcohol consumption and the three functional tests separately. The results showed that harmful drinking was associated with lower CPPS scores compared to non-problem drinking. Among harmful drinking men, the decrease in CPPS scores was explained by all three tests equally and exceptionally by GS among women. Non-drinking was also associated with decreased CPPS, linked to lower GS and CR scores in men, and only lower GS scores in women. The study revealed a reduced physical performance in the non-drinking and harmful drinking groups compared to non-problem drinking.

Disrupted executive cerebro-cerebellar functional connectivity in alcohol use disorder

BACKGROUND

Alcohol use disorder (AUD) affects 283 million people worldwide and its prevalence is increasing. Despite the role of the cerebellum in executive control and its sensitivity to alcohol, few studies have assessed its involvement in AUD-relevant functional networks. The goal of this study is to compare resting-state functional connectivity (FC) patterns in abstinent adults with a history of AUD and controls (CTL). We hypothesized that group differences in cerebro-cerebellar FC would be present, particularly within the frontoparietal/executive control network (FPN).

METHODS

Twenty-eight participants completed a resting-state functional magnetic resonance imaging (rsfMRI) study. CTL participants had no history of AUD, comorbid psychological conditions, or recent heavy drinking and/or drug use. AUD participants had a history of AUD, with sobriety for at least 30 days prior to data collection. Multivariate pattern analysis, an agnostic, whole-brain approach, was used to identify regions with significant differences in FC between groups. Seed-based analyses were then conducted to determine the directionality and extent of these FC differences. Associations between FC strength and executive function were assessed using correlations with Wisconsin Card Sorting Test (WCST) performance.

RESULTS

There were significant group differences in FC in nodes of the FPN, ventral attention network, and default mode network. Post hoc analyses predominantly identified FC differences within the cerebro-cerebellar FPN, with AUD showing significantly less FC within the FPN. In AUD, FC strength between FPN clusters identified in the multivariate pattern analysis (MVPA) analysis (Left Crus II, Right Frontal Cortex) was positively associated with performance on the WCST.

CONCLUSIONS

Our results show less engagement of the FPN in individuals with AUD than in CTL. FC strength within this network was positively associated with performance on the WCST. These findings suggest that long-term heavy drinking alters cerebro-cerebellar FC, particularly within networks that are involved in executive function.

Alcohol induces apoptosis and autophagy in microglia BV-2 cells

Alcohol (ethanol) has proven to be toxic to nearly all organs, with the brain being one of the principal targets. As one of the important components of the brain's blood-brain barrier (BBB) and central nervous system, the state of microglia may be associated with some symptoms of alcohol intoxication. In the present study, microglia BV-2 cells were exposed to various concentrations of alcohol for 3 or 12 h, imitating different stages of drunkenness after alcohol use, respectively. From the perspective of the autophagy-phagocytosis axis, our findings show that alcohol alters autophagy levels or promotes apoptosis in BV-2 cells. The current study adds to the understanding of the action mechanisms of alcohol neurotoxicity. We anticipate that this study will increase public awareness of alcohol's negative effects and contribute to the creation of novel alcoholism treatment approaches.

Emotional Incontinence: A Case Report of Pseudobulbar Affect in the Setting of Alcohol Use Disorder

Pseudobulbar affect (PBA) manifests as a disconnect between emotional feelings and emotional expressions. The impact of pseudobulbar affect on social, occupational, and interpersonal functioning is substantial. It results in poor quality of social interactions and poor overall quality of life. Instances of pseudobulbar affect with no underlying neuropsychiatric disorders are rarely reported in the literature. Although alcohol use has been associated with traumatic brain injuries (TBI), alcohol as a direct cause of pseudobulbar palsy has rarely been reported. Our case presents a unique situation with no known underlying primary neurologic disorder but evidence from clinical history, physical examination, and laboratory tests indicative of severe alcohol use disorder. This case represents the rare instances where the disease etiology is unusual and reminds the health care provider to consider the role of alcohol in the pathophysiology of pseudobulbar affect. More research is needed to understand the role of alcohol in the etiology of pseudobulbar affect in the absence of any known underlying neuropsychiatric disorder.