Imaging Shows Patterns of Brain Damage in Alcoholics

Technology helps study how alcohol can damage the brain

Doctors Examine MRIs
MRIs Can Reveal Alcoholic Brain Damage. © Getty Images

Innovations in imaging technology have helped alcohol researchers study how alcohol damages internal organs, such as the brain and the liver. Using computed tomography (CT), magnetic resonance imaging (MRI), and diffusion tensor imaging (DTI), researchers are finding direct effects of chronic drinking.

Imaging studies have revealed a consistent association between heavy drinking and physical brain damage, even in the absence of other usual symptoms of severe alcoholism—chronic liver disease or alcohol-induced dementia.

Brain Shrinkage and Alcoholic Behavior

The shrinkage observed seems to be more extensive in the cortex of the frontal lobe, which is believed to be the seat of higher intellectual functions. This shrinkage generally increases with age, at least in men.

Repeated imaging of a group of alcoholics who continued drinking over a five-year period revealed progressive brain shrinkage that significantly exceeded normal age-related shrinkage. The rate of frontal cortex shrinkage correlates closely with the amount of alcohol consumed.

But this shrinkage has also been observed in deeper brain regions, including brain structures associated with memory, as well as in the cerebellum, which helps regulate coordination and balance.

The brain tries to compensate for these losses by activating brain regions to perform the tasks normally done by the shrunken regions. Functional MRI shows more use of some areas in the alcoholic test subjects compared with control subjects.

This enables alcoholics to maintain performance even as their brains are being injured by the alcohol.

Reversing the Effects of Alcohol

A key goal of imaging in alcoholism research is to detect changes in specific brain regions that can be correlated with alcohol-related behaviors. Imaging of the cerebellum has linked both shrinkages and decreased blood flow to impaired balance and gait.

This may lead to falls, especially among older alcoholics.

Researchers do not agree on the effect this brain shrinkage has on memory loss and problem-solving skills. Some studies show no effect, while others have reported some loss in those skills associated with alcohol-induced brain shrinkage.

However, these effects are usually reversed with alcohol abstinence. Even quitting drinking for three to four weeks has shown to reverse the effects on memory loss and problem-solving skills. MRI shows some recovery of tissue volume after a period of abstinence. But when an alcoholic returns to drinking they show further reductions in brain tissue volume.

"More recent advances in imaging techniques are allowing investigators to study alcohol dependence itself. Scientists are beginning to measure alcohol’s effects on mood, emotional states, craving, and cognition while simultaneously assessing metabolic, physiologic, and neurochemical function in the brain," said former NIAAA Director Enoch Gordis, M.D. "These innovations in imaging technology will help not only the alcohol field but also all fields of medicine where biology and behavior are so closely linked."

Sources:

Rosenbloom MJ, Pfefferbaum A. Magnetic resonance imaging of the living brain: evidence for brain degeneration among alcoholics and recovery with abstinenceAlcohol Res Health. 2008;31(4):362-76.

Zahr NM. Structural and microstructural imaging of the brain in alcohol use disorders. Handbook of Clinical Neurology Alcohol and the Nervous System. 2014:275-290. doi:10.1016/b978-0-444-62619-6.00017-3.

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