Alcohol-Related Cognitive Disorders PDF

Summary

This chapter provides an overview of alcohol-related cognitive disorders, including their acute and chronic effects. It discusses the impact of alcohol on various cognitive functions and explores conditions like Wernicke's encephalopathy and Korsakoff's syndrome. This chapter aims to clarify the neurological consequences of chronic alcohol abuse.

Full Transcript

# Alcohol-Related Cognitive Disorders ## 18.1 Introduction - Western culture accepts alcohol consumption - Dutch Trimbos Institute shows 77.6% of Dutch adults consumed alcohol in the last year. - 6.9% of Dutch adults drink excessively - Excessive drinkers consume more than 21 glasses (men) or 14...

# Alcohol-Related Cognitive Disorders ## 18.1 Introduction - Western culture accepts alcohol consumption - Dutch Trimbos Institute shows 77.6% of Dutch adults consumed alcohol in the last year. - 6.9% of Dutch adults drink excessively - Excessive drinkers consume more than 21 glasses (men) or 14 glasses (women) per week - small glass of beer (20 cl) - small glass of wine - shot glass of spirits - Drinking alcohol increases the risk of: - cardiovascular disease - various forms of cancer - gastrointestinal system diseases - Alcohol consumption causes chronic inflammatory reactions throughout body - Accidents under the influence of alcohol lead to injuries and deaths - Dutch nutrition centre advises not to drink at all, or very moderately ## 18.2 Alcohol Use Disorder - Problem alcohol use is referred to as Alcohol Use Disorder - Light consumption (1-8 alcoholic drinks per week) can cause health damage and even be classified as alcohol dependence. - The terms "alcohol addiction" and "alcoholism" are no longer used due to stigmatisation of the term "addict" - The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) defines Alcohol Use Disorder as a problematic drinking pattern that leads to clinically significant impairment or distress. - The DSM-5 outlines 11 symptoms for Alcohol Use Disorder. - Mild Alcohol Use Disorder (2-3 symptoms) - Moderate Alcohol Use Disorder (3-4 symptoms) - Severe Alcohol Use Disorder (more than 6 symptoms) - Treatment for AUD usually takes place in inpatient or outpatient addiction services. - Shorter interventions to stop or reduce alcohol consumption by general practitioner can be effective for all - For individuals admitted to specialised mental health care, these interventions are insufficient due to the complexity of the (psychological and social) problems. - Specialist centers primarily treat alcohol users, but other substances are used to a lesser extent. - About the same number of people seek care for alcohol use and other substances. ## 18.3 Alcohol-Related Cognitive Disorder - ARCD is an umbrella term that describes the long-term, cognitive impairment(s) associated with alcohol use. - DSM-5 refers to them as mild or major alcohol-related neurocognitive disorder. - Literature uses "alcohol-related brain damage" or "ARBD" to refer to brain damage, which implies an explanation for the cognitive impairment, which is not always true. - ARBD is also used to refer to patients with cognitive impairment and alcohol problems, even without brain imaging. - The term Alcohol-Related Cognitive Disorder is preferable because it implies a suspected relationship with problematic alcohol use, but does not necessarily imply that alcohol is the cause. ## 18.4 Acute Effects of Alcohol Abuse - Alcohol mimics the neurotransmitter GABA, which inhibits activity in the nervous system. - This leads to brain functions working less efficiently - Small amounts of alcohol lead to: - feeling relaxed - talking more easily - difficulty with thinking and analysing - These are probably due to inhibition of activity in the frontal lobe. - Larger amounts of alcohol: - motor skill deterioration - slowness - memory gaps - possibly related to inhibitory activity in the cerebellum, hippocampus and parietal cortex. - Very large amounts of alcohol may suppress breathing and coma, due to the inhibitory effects of alcohol on the brainstem and pons. - 28% of adolescents admitted to the emergency room with acute alcohol intoxication experienced respiratory depression. ## 18.5 Chronic Effects of Alcohol Abuse ### 18.5.1 Brain Damage in Chronic Alcohol Abuse - The main effect of chronic alcohol abuse on the brain is volume loss of the frontal cortex, reflecting both grey and white matter loss and increased cerebrospinal fluid volumes in areas of tissue loss - Less apparent volume loss in: - parietal cortex - hippocampus - cerebellum - diencephalon (the thalamus with surrounding areas such as the mammillary bodies) - The extent of frontal volume loss is associated with the risk of alcohol relapse. - Abnormalities are referred to as Alcoholic Encephalopathy. ### 18.5.2 Cognitive Consequences of Chronic Alcohol Abuse - Excessive drinking is a risk factor for cognitive impairments. - Cognitive dysfunctions vary in severity and nature. - Cognitive Impairment is often found in: - executive function - social cognition - working memory - visuospatial functions - episodic memory - About 20% of people with Alcohol Use Disorder experience cognitive problems as a result of drinking - Most studies are done with patients who have recently abstained from alcohol; less is known about the long-term effects. - A clear association between the severity of Alcohol Use Disorder and cognitive outcome. - Studies on older individuals who consume alcohol show evidence of accelerated cognitive decline or dementia. - Older adults with MCI and increased alcohol consumption showed faster cognitive decline over time - The group with an increased risk of cognitive problems consumed around 7 to 14 alcoholic drinks per week. - Older alcohol mal-users seeking treatment in addiction care are growing. ## 18.6 Aetiology of the Neurological and Neuropsychological Consequences of Chronic Alcohol Abuse ### 18.6.1 Neurotoxicity - It is unclear whether alcohol itself is neurotoxic, but it is known to cause extensive somatic complications. - Brain atrophy in individuals with Alcohol Use Disorders is likely due to demyelination rather than cell death. - This atrophy (shrinkage) has been shown to be reversible, for individuals who have abstained for a long period of time and in animals. - Likely due to remyelination after discontinuation of use - Individuals who recover well after abstinence are "uncomplicated." - Individuals with chronic brain damage and cognitive problems are "complicated." ### 18.6.2 The Continuity Hypothesis: A Dose-Response Relationship? - Several factors are important in understanding the relationship between alcohol and brain function: - amount of alcohol consumed - frequency of drinking - age at which alcohol use started - duration of use - number of times the person has stopped drinking alcohol - There is a continuum, from light drinkers with moderate consumption, to heavy drinkers with long periods of excessive drinking and multiple relapses. - The "continuity hypothesis" postulates a direct relationship between the severity and extent of alcohol consumption and the severity of the cognitive consequences and brain changes. - However, there is little convincing supporting evidence. - The relationship may only exist within the group with a relatively uncomplicated cognitive course. - More recent research did not show a relationship between the severity of alcohol use in adolescents and changes in grey and white matter. ### 18.6.3 Complicated Alcohol Use: Comorbid Disorders with Neurological Consequences - Comorbid conditions that can have neurological consequences in individuals with chronic alcohol use: - head injury - cardiovascular disease - liver damage - malnutrition - **Head Injury** - Falling under the influence of alcohol is common due to muscle weakness, neuropathy and acute intoxication. - 30% to 50% of patients with traumatic brain injury have been under the influence of alcohol at the time of injury. - People with severe AUD tend to live in isolation, and therefore may not receive medical attention. - Excessive alcohol increases the risk of cardiovascular disease and type 2 diabetes mellitus. - **Liver Damage** - Alcohol is broken down in the liver. - Excessive alcohol consumption can lead to liver cirrhosis (scarring), hepatitis (inflammation of the liver) and ultimately liver failure. - In the later stages of liver disease, cognition may vary across days. - Cognitive impairments might be present on some days and absent on others. - Liver failure can lead to fluctuating alertness, attention deficits, sleep problems, psychotic symptoms, and personality changes. - Liver function disorders are referred to as hepatic encephalopathy. - Their fluctuating course is related to the functioning of the liver and the amount of waste products (ammonia) in the body, but also to specific damage to the basal ganglia. - **Malnutrition** - Excessive alcohol consumption reduces hunger. - Individuals with severe AUD often eat little and have an unhealthy diet. - Alcohol contains few nutrients, but many calories. - Vitamin B1 deficiency can lead to Wernicke's encephalopathy. - Malnutrition can impair cognitive functioning regardless of acute neurologic problems. - **Foetal Alcohol Syndrome** - Problematic alcohol use in pregnant women can cause fetal alcohol syndrome, which can lead to developmental disorders. - FAS is characterized by: - folded skin in the corner of the eye - low nasal bridge - short nose - small head circumference - small eye openings - small face - thin upper lip - smooth philtrum (no ridge between nose and lips) - Children with FAS also have lower-than-average intelligence, social-cognitive deficits, and problems in social interaction, and are oversensitive to sensory information (tactile, visual, and auditory). - FAS is a subgroup of a much larger group of children with Fetal Alcohol Spectrum Syndrome (FASD). - Children with FASD may not have all three characteristics mentioned above, but they may have one or two of these characteristics. - It is important to obtain background information about prenatal drinking when diagnosing FASD. ## 18.7 Recovery After Stopping Alcohol Consumption - Complete cessation of alcohol use is called detoxification or "detox". - It should be done under the supervision of professionals working in addiction care. - Brain volume typically increases after alcohol cessation, leading to improved cognitive functioning. - The biggest recovery occurs in the first four to eight weeks of abstinence. - Improvements are seen up to one year after alcohol cessation. - It is important to wait least six weeks after abstinence before performing a neuropsychological assessment. - There is recovery across different cognitive domains, although some domains, such as inhibition, recover more slowly or to a lesser extent. - It is difficult to determine causality. - Impairments could be a consequence of alcohol abuse or could cause the addiction. - Emotion recognition may recover after three months of abstinence, but little research has been performed on social cognition and those individuals. - It is difficult to predict which patients will recover cognitively due to many factors. - older patients tend to have worse cognitive outcomes. - cognitive dysfunction at admission predicts the extent and course of recovery. - better cognitive performance predicts better recovery. - Smokers who drink may recover less well than non-smokers. ## 18.8 Wernicke's Encephalopathy - People with severe AUD often neglect themselves and live socially isolated lives. - This increases the risk of a thiamine deficiency (vitamin B1) as a result of malnutrition. - Wernicke's encephalopathy is a specific consequence of malnutrition, first described by Carl Wernicke in 1848. - It was initially described as damage and aphasia. ## 18.9 Korsakoff's Syndrome - Korsakoff's syndrome may develop after a delayed or inadequately treated Wernicke's encephalopathy. - It is a neuropsychiatric disorder, characterized by a disproportionate impairment in episodic memory relative to other cognitive domains, in the absence of illness insight. - Confabulations are also often present. - The DSM-5 refers to it as Major Alcohol-Induced Neurocognitive Disorder, Amnestic-Confabulatory type. - The prevalence of Korsakoff's syndrome was 4.8 per 10,000 in The Hague, Netherlands in 1987, and 3 per 10,000 in South Holland, Netherlands in 1992. - No recent data exist on the prevalence of Korsakoff's syndrome in the Netherlands. - Most patients with Korsakoff's syndrome have or have had alcohol use disorder, but thiamine deficiency, not alcohol itself, causes damage. - Korsakoff's syndrome can also occur in those with hyperemesis gravidarum (severe pregnancy vomiting), after bariatric surgery, and in cancer. ## 18.10 Alcohol Dementia - Older literature sometimes referred to alcohol dementia or lateral alcohol-related dementia. - It was assumed to be progressive in nature with irreversible cognitive impairments, but strong evidence supporting it as a distinct syndrome is lacking. - Often used to classify severely affected patients in whom alcohol-related brain damage may be one of many contributing factors to the dementia syndrome. - Sometimes patients with Korsakoff's syndrome are even included. - Patients who do not meet the Korsakoff syndrome criteria may meet the dementia criteria. - It is difficult to determine the aetiology of dementia syndrome, as it may be the result of somatic or psychiatric comorbidity, social factors, or addiction history. - Alcohol dementia is not due to pathophysiolog or progressive neurodegeneration solely as a result of alcohol abuse. ## 18.11 In Conclusion - Although alcohol consumption is socially accepted, excessive drinking may lead to social, physical and cognitive problems. - Quitting drinking often leads to improvement in cognitive functioning, but maintaining abstinence is difficult. - Individuals with alcohol use disorder are at risk of developing neurological complications, such as Wernicke's encephalopathy and Korsakoff's syndrome. - Comorbidity of alcohol abuse, such as head trauma, cardiovascular disease, liver damage and cancer reduces the number of healthy life-years and complicates care. - Diagnosing possible cognitive deficits is important after abstinence because it requires support and monitoring in daily life, which may stress the need for specialist care.

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