Alcohol Alert - Alcohol's Damaging Effects on Brain

Difficulty in walking, blurred vision , slurred speech , slowed reaction times , impaired memory: Clearly, alcohol affects the brain. Some of these impairments are detectable after only one or two drinks and quickly resolve when drinking stops. On the other hand, a person who drinks heavily over a long period of time may have brain deficits that persist well after he or she achieves sobriety. Exactly how alcohol affects the brain and the likelihood of reversing the impact of heavy drinking on the brain remain hot topics in alcohol research today.

A number of factors influence how and to what extent alcohol affects the brain, including :
• how much and how often a person drinks;
• the age at which he or she first began drinking, and
how long he or she has been drinking;
• the person’s age, level of education, gender, genetic
background, and family history of alcoholism;
• whether he or she is at risk as a result of prenatal
alcohol exposure; and
• his or her general health status.

Blackouts and Memory Lapses:

Alcohol can produce detectable impairments in memory after only a few drinks and, as the amount of alcohol increases, so does the degree of impairment. Large quantities of alcohol, especially when consumed quickly and on an empty stomach, can produce a blackout, or an
interval of time for which the intoxicated person cannot recall key details of events, or even entire events. Blackouts are much more common among social drinkers than previously assumed and should be viewed as a potential consequence of acute intoxication regardless of age or whether the drinker is clinically dependent on alcohol

Are Women More Vulnerable to Alcohol’s Effects on the Brain?

Women are more vulnerable than men to many of the medical consequences of alcohol use. For example, alcoholic women develop cirrhosis , alcohol-induced damage of the heart muscle (i.e., cardiomyopathy) , and nerve damage (i.e., peripheral neuropathy) after fewer years of heavy drinking than do alcoholic men. Studies comparing men and women’s sensitivity to alcohol-induced brain damage,indicate that women’s brains,like their other organs, are more vulnerable to alcohol induced damage than men’s.

Binge Drinking and Blackouts:

Drinkers who experience blackouts typically drink too much and too quickly, which causes their blood alcohol levels to rise very rapidly. College students may be at particular risk for experiencing a blackout, as an alarming number of college students engage in binge drinking. Binge drinking, for a typical adult,is defined as consuming five or more drinks in about 2 hours for men, or four or more drinks for women.

Regardless of the amount of alcohol consumption, females—a group infrequently studied in the literature on blackouts—are at greater risk than males for experiencing black-outs. A woman’s tendency to black out more easily probably results from differences in how men and women metabolize alcohol. Females also may be more susceptible than males to milder forms of alcohol induced memory impairments, even when men and women consume comparable amounts of alcohol

Damage may be a result of the direct effects of alcohol on the brain or may result indirectly, from a poor general health status or from severe liver disease. For example, thiamine deficiency is a common occurrence in people with alcoholism and results from poor overall nutrition. Thiamine, also known as vitamin B1, is an essential nutrient required by all tissues, including the brain. Thiamine is found in foods such as meat and poultry; whole grain cereals; nuts; and dried beans, peas, and soybeans.

Wernicke–Korsakoff Syndrome:
Up to 80 percent of alcoholics, however, have a deficiency in thiamine, and some of these people will go on to develop serious brain disorders such as Wernicke–Korsakoff syndrom (WKS)
The symptoms of Wernicke’s encephalopathy include: mental confusion, paralysis of the nerves that move the eyes (i.e., oculomotor disturbances), and difficulty with muscle coordination. For example, patients with Wernicke’s encephalopathy may be too confused to find their way out of a room or may not even be able to walk. Approximately 80 to 90 percent of alcoholics with
Wernicke’s encephalopathy also develop Korsakoff ’s psychosis, a chronic and debilitating syndrome characterized by persistent learning and memory problems.

Patients with Korsakoff ’s psychosis are forgetful and quickly frustrated and have difficulty with walking and coordination. Although these patients have problems remembering old information (i.e., retrograde amnesia), it is their difficulty in “laying down” new information (i.e.,anterograde amnesia) that is the most striking. For example, these patients can discuss in detail an event in their lives, but an hour later

Liver Disease:

Most people realize that heavy, long-term drinking can damage the liver, the organ chiefly responsible for breaking down alcohol into harmless byproducts and clearing it from the body. But people may not be aware that prolonged liver dysfunction, such as liver cirrhosis resulting from excessive alcohol consumption, can harm the brain, leading to a serious and potentially fatal brain disorder known as hepatic encephalopathy. Hepatic encephalopathy can cause changes in sleep patterns, mood, and personality; psychiatric conditions such as anxiety and depression; severe cognitive effects such as shortened attention span; and problems with coordination such as a flapping or shaking of the hands (called asterixis). In the most serious cases, patients may slip into a coma (i.e., hepatic coma), which can be fatal.

Alcohol and the Developing Brain:

Drinking during pregnancy can lead to a range of physical, learning, and behavioral effects in the developing brain, the most serious of which is a collection of symptoms known as fetal alcohol syndrome (FAS). Children with FAS may have distinct facial features. FAS infants also are markedly smaller than average. Their brains may have less volume (i.e.,microencephaly). And they may have fewer numbers of brain cells (i.e., neurons) or fewer neurons that are able to function correctly, leading to long-term problems in learning and behavior.

Summary:

Alcoholics are not all alike. They experience different degrees of impairment, and the disease has different origins for different people. Consequently, researchers have not found conclusive evidence that any one variable is solely responsible for the brain deficits found in alcoholics. Characterizing what makes some alcoholics vulnerable to brain damage whereas others are not
remains the subject of active research. The good news is that most alcoholics with cognitive
impairment show at least some improvement in brain structure and functioning within a year of abstinence, though some people take much longer. Clinicians must consider a variety of treatment methods to help people stop drinking and to recover from alcohol-related brain impairments, and tailor these treatments to the individual patient. Advanced technology will have an important role in developing these therapies. Clinicians can use brain imaging techniques to monitor the course and success of treatment, because imaging can reveal structural, functional, and biochemical changes in living patients over time. Promising new medications also are in the early stages of development, as researchers strive to design therapies that can help prevent alcohol’s harmful effects and promote the growth of new brain cells to take the place of those that have been damaged by alcohol might not remember ever having the conversation.

Ref:U.S. Department of Health & Human Services
National Institutes of Health & National Institute on Alcohol Abuse and Alcoholism