Neurological manifestations of excessive alcohol consumption

Alcohol and alcoholism associated neurological disorders: Current updates in a global perspective and recent recommendations

Alcohol use disorder (AUD) is a medical condition that impairs a person's ability to stop or manage their drinking in the face of negative social, occupational, or health consequences. AUD is defined by the National Institute on Alcohol Abuse and Alcoholism as a "severe problem". The central nervous system is the primary target of alcohol's adverse effects. It is crucial to identify various neurological disorders associated with AUD, including alcohol withdrawal syndrome, Wernicke-Korsakoff syndrome, Marchiafava-Bignami disease, dementia, and neuropathy. To gain a better understanding of the neurological environment of alcoholism and to shed light on the role of various neurotransmitters in the phenomenon of alcoholism. A comprehensive search of online databases, including PubMed, EMBASE, Web of Science, and Google Scholar, was conducted to identify relevant articles. Several neurotransmitters (dopamine, gamma-aminobutyric acid, serotonin, and glutamate) have been linked to alcoholism due to a brain imbalance. Alcoholism appears to be a complex genetic disorder, with variations in many genes influencing risk. Some of these genes have been identified, including two alcohol metabolism genes, alcohol dehydrogenase 1B gene and aldehyde dehydrogenase 2 gene, which have the most potent known effects on the risk of alcoholism. Neuronal degeneration and demyelination in people with AUD may be caused by neuronal damage, nutrient deficiencies, and blood brain barrier dysfunction; however, the underlying mechanism is unknown. This review will provide a detailed overview of the neurobiology of alcohol addiction, followed by recent studies published in the genetics of alcohol addiction, molecular mechanism and detailed information on the various acute and chronic neurological manifestations of alcoholism for the Future research.

Could Alcohol Abuse and Dependence on Junk Foods Inducing Obesity and/or Illicit Drug Use Represent Danger to Liver in Young People with Altered Psychological/Relational Spheres or Emotional Problems?

Recent data show that young people, mainly due to the pressure of some risk factors or due to disrupted interpersonal relationships, utilise greater reward value and display greater sensitivity to the reinforcing properties of “pleasurable stimuli”, specifically in those situations in which an enhanced dopamine release is present. Alcoholic beverages, foods rich in sugar and fat, and illicit drug use are pleasurable feelings associated with rewards. Research shows that there is a link between substance abuse and obesity in brain functioning. Still, alcohol excess is central in leading to obesity and obesity-related morbidities, such as hepatic steatosis, mainly when associated with illicit drug dependence and negative eating behaviours in young people. It is ascertained that long-term drinking causes mental damage, similarly to drug abuse, but also affects liver function. Indeed, beyond the pharmacokinetic interactions of alcohol with drugs, occurring in the liver due to the same metabolic enzymes, there are also pharmacodynamic interactions of both substances in the CNS. To complicate matters, an important noxious effect of junk foods consists of inducing obesity and obesity-related NAFLD. In this review, we focus on some key mechanisms underlying the impact of these addictions on the liver, as well as those on the CNS.

Toxic and Nutritional Optic Neuropathies—An Updated Mini-Review

Optic neuropathies constitute a group of conditions with various etiologies and might be caused by different factors; we can distinguish the genetic and acquired causes of optic neuropathies. Even though the symptoms are not highly specific, this condition is primarily characterized by unilateral or bilateral vision loss with worsening color detection. The loss may be acute or gradual depending on the causation. In this article, we included a specification of toxic optic neuropathy (TON) mainly triggered by alcohol abuse and also the usage of other substances, including drugs or methanol, as well as intoxication by metals, organic solvents, or carbon dioxide. Nutritional deficiencies, vitamin absorption disorder, and anemia, which usually appear during excessive alcohol intake, and their effect on the etiology of the optic neuropathy have been likewise discussed.

Rethinking Unhealthy Alcohol Use in the United States: A Structured Review

Greater than moderate alcohol use spans a continuum that includes high levels of total alcohol consumed per period (heavy drinking) as well as episodes of intense drinking (binges) and can give rise to alcohol use disorder (AUD) when associated with an inability to control alcohol use despite negative consequences. Although moderate drinking and AUD have standard, operable definitions in the United States (US), a significant “gray area” remains in which an individual may exceed recommended drinking guidelines but does not meet the criteria for AUD (hereafter referred to as unhealthy alcohol use). To address this need, we conducted a structured literature search to evaluate how this gray area is defined and assess its burden within the US. For purposes of this review, we will refer to this gray area as “unhealthy alcohol use.” Although numerous terms are used to describe various unsafe drinking practices, our review did not find any studies in which the specific prevalence and/or burden of unhealthy alcohol use was evaluated. That is, we found no studies that focus exclusively on individuals who exceed moderate drinking guidelines but do not meet AUD criteria. Furthermore, we did not discover an established framework for identifying individuals with unhealthy alcohol use. The lack of a consistent framework for identifying unhealthy alcohol users has significant implications for patient management and disease burden assessment. Therefore, we propose the following framework in which unhealthy alcohol use comprises 2 distinct subpopulations: those at risk of experiencing alcohol-related consequences and those who have subthreshold problems associated with use. The former, termed “risky drinkers,” are defined by exceeding recommended guidelines for moderate drinking (⩽1 or 2 drinks per day for women and men, respectively). People with subthreshold problems associated with use, defined as exhibiting exactly 1 AUD symptom, would be classified as “problematic drinkers” within this proposed framework. These definitions would help bring the core elements of unhealthy alcohol use into focus, which in turn would help identify and provide management strategies sooner to those affected and reduce the overall burden of unhealthy alcohol use.

Alcoholic Liver Disease Among Patients with Wernicke Encephalopathy: A Multicenter Observational Study

BACKGROUND

data regarding the association between Wernicke encephalopathy (WE) and alcoholic liver disease (ALD) are scarce in spite of alcohol consumption being the main risk factor for WE.

AIMS

to describe the frequency of ALD in a cohort of patients diagnosed with WE and alcohol use disorders (AUDs) and to compare the characteristics of WE patients with and without ALD.

METHODS

we conducted an observational study in 21 centers through a nationwide registry of the Spanish Society of Internal Medicine. WE Caine criteria were applied and demographic, clinical, and outcome variables were analyzed.

RESULTS

434 patients were included in the study, of which 372 were men (85.7%), and the mean age was 55 ± 11.8 years. ALD was present in 162 (37.3%) patients and we found a higher percentage of cases with tremor, flapping and hallucinations in the ALD group. A total of 22 patients (5.0%) died during admission (7.4% with ALD vs 3.7% without ALD; P = 0.087). Among the ALD patients, a relationship between mortality and the presence of anemia (Odds ratio [OR]=4.6 Confidence interval [CI]95% 1.1-18.8; P = 0.034), low level of consciousness (OR=4.9 CI95% 1.1-21.2; P = 0.031) and previous diagnosis of cancer (OR=10.3 CI95% 1.8-59.5; P = 0.009) was detected. Complete recovery was achieved by 27 patients with ALD (17.8%) and 71 (27.8%) without ALD (P = 0.030).

CONCLUSION

the association of WE and ALD in patients with AUDs is frequent and potentially linked to differences in clinical presentation and to poorer prognosis, as compared to alcoholic patients with WE without ALD.

Role of Alcohol Drinking in Alzheimer's Disease, Parkinson's Disease, and Amyotrophic Lateral Sclerosis

Neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD) and amyotrophic lateral sclerosis (ALS), increase as the population ages around the world. Environmental factors also play an important role in most cases. Alcohol consumption exists extensively and it acts as one of the environmental factors that promotes these neurodegenerative diseases. The brain is a major target for the actions of alcohol, and heavy alcohol consumption has long been associated with brain damage. Chronic alcohol intake leads to elevated glutamate-induced excitotoxicity, oxidative stress and permanent neuronal damage associated with malnutrition. The relationship and contributing mechanisms of alcohol with these three diseases are different. Epidemiological studies have reported a reduction in the prevalence of Alzheimer’s disease in individuals who drink low amounts of alcohol; low or moderate concentrations of ethanol protect against β-amyloid (Aβ) toxicity in hippocampal neurons; and excessive amounts of ethanol increase accumulation of Aβ and Tau phosphorylation. Alcohol has been suggested to be either protective of, or not associated with, PD. However, experimental animal studies indicate that chronic heavy alcohol consumption may have dopamine neurotoxic effects through the induction of Cytochrome P450 2E1 (CYP2E1) and an increase in the amount of α-Synuclein (αSYN) relevant to PD. The findings on the association between alcohol consumption and ALS are inconsistent; a recent population-based study suggests that alcohol drinking seems to not influence the risk of developing ALS. Additional research is needed to clarify the potential etiological involvement of alcohol intake in causing or resulting in major neurodegenerative diseases, which will eventually lead to potential therapeutics against these alcoholic neurodegenerative diseases.