A person who suffers from long term alcohol usage or sometimes even short term usage may suffer from difficulty 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.

We do know that heavy drinking may have extensive and far–reaching effects on the brain, ranging from simple “slips” in memory to permanent and debilitating conditions that require lifetime custodial care. And even moderate drinking leads to short–term impairment, as shown by extensive research on the impact of drinking on driving.

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 VOLUNERABLE?

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, and nerve damage, after fewer years of heavy drinking than do alcoholic men. 

BRAIN DAMAGE FROM OTHER CAUSES RELATED TO ALCOHOL

People who have been drinking large amounts of alcohol for long periods of time run the risk of developing serious and persistent changes in the brain. 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.

HAVE ANY OF YOUR HEARD OF "WETBRAIN"  I PERSONALLY HAVE A FRIEND THAT SUFFERS FROM THIS.  WHAT A WONDERFUL FRIEND IN HIGH SCHOOL AND NOW BARELY HAS THE POTENTIAL OF BAGGING GROCIERIES AT A GROCERY STORE. 

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. Many foods in the United States commonly are fortified with thiamine, including breads and cereals. As a result, most people consume sufficient amounts of thiamine in their diets. The typical intake for most Americans is 2 mg/day; the Recommended Daily Allowance is 1.2 mg/day for men and 1.1 mg/day for women.

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 syndrome (WKS). WKS is a disease that consists of two separate syndromes, a short–lived and severe condition called Wernicke’s encephalopathy and a long–lasting and debilitating condition known as Korsakoff’s psychosis.

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. Many Wernicke’s encephalopathy patients, however, do not exhibit all three of these signs and symptoms, and clinicians working with alcoholics must be aware that this disorder may be present even if the patient shows only one or two of them. In fact, studies performed after death indicate that many cases of thiamine deficiency–related encephalopathy may not be diagnosed in life because not all the “classic” signs and symptoms were present or recognized.

Human Brain

Schematic drawing of the human brain, showing regions vulnerable to alcoholism-related abnormalities.

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 might not remember ever having the conversation.