Damage to the Brain's Corpus Callosum—How It Impacts Brain Health

The corpus callosum is part of the brain composed of a thick bundle of nerve fibers. This structure connects the left and right hemispheres and allows the two sides of the brain to communicate and work together to control body functions. 

As part of the central nervous system, the corpus callosum plays a critical role in a variety of functions, including processing sensory and motor information, coordinating physical movements, and high-level cognitive functions such as language processing and memory consolidation.

This article discusses the functions of the corpus callosum and the conditions that may affect it. It also covers how to keep this part of your brain healthy.

What Is the Main Function of the Corpus Callosum?

The human brain is divided into a right hemisphere and a left hemisphere. Each side of the brain controls functions on the opposite side of the body. To control the body's movement, the two halves of the brain must communicate and work together to produce fluid, coordinated movements. The corpus callosum facilitates and integrates this communication.

The corpus callosum acts as a bridge between the two sides of the brain. Just as a bridge provides the path for communication and transportation between two separated land masses, the corpus callosum enables communication and coordination between the brain's two hemispheres. Because information is shared between the left and right sides, essential functions such as sensory perception, language, and cognitive processes can occur. 

Without this connection, the hemispheres could not send information back and forth. Having this pathway, however, allows for the rapid transmission of information.

Communication between the two hemispheres is also essential for many other functions, including:

• Visual-spatial integration
• Sensory perception
• Motor control
• Language processing
• Problem-solving
• Maintaining balance

How the Corpus Callosum Impacts Cognitive Functioning

The corpus callosum does not directly affect or control specific areas of the body. Instead, it transfers and integrates information between the brain's hemispheres. This part of the brain is essential to mental functioning, particularly language production and processing.

In most people, the left hemisphere is the dominant area controlling language. However, the right side of the brain still plays an essential role in certain aspects of language processing, including the ability to interpret emotional tone.

Some other cognitive functions that the corpus callosum influences include:

• Learning 
• Memory
• Thinking
• Three-dimensional visual ability
• Visual reaction time
• Executive function

Where Is the Corpus Callosum Located?

The corpus callosum is found below the cerebral cortex. The band of nerve fibers that make up the cerebral cortex stretches along the midline of the brain in order to connect the left and right hemispheres. 

Examples of How the Corpus Callosum Functions in Daily Life

Because the corpus callosum communicates information between the two hemispheres, people use it constantly as they perform various motor and cognitive tasks.

Reading

Reading is an example of how the brain divides and splits labor between the two sides of the brain and then brings this information together to perform a task.

The right side of the brain is responsible for processing the visual details of the words on the page. It also handles the emotional content of the material, giving nuance and emotional weight to the things we read. The left side of the brain is where much of the actual language processing occurs, allowing us to draw meaning from the words on the page. 

By connecting the two sides of the brain, the corpus callosum facilitates the transfer of visual and emotional information from the right side and relays the meaning of the text from the left side. It conveys and integrates the disparate aspects of reading into a cohesive and harmonious experience that seems, to us, perfectly seamless.

Riding a Bike

Riding a bike is another example of an activity that involves the corpus callosum. Both sides of the brain control physical actions on one side of the body, and the corpus callosum communicates information between the two sides to smoothly coordinate these complex movements.

How Damage to the Corpus Callosum Impacts the Brain

Damage, disease, developmental disorders, and surgery can all impair how the corpus callosum works. If the corpus callosum is damaged or severed, it can harm or prevent the two sides of the brain from communicating, resulting in a loss of functioning. 

Agenesis of the Corpus Callosum

Agenesis of the corpus callosum is a developmental condition in which children are born with a malformed or absent corpus callosum. The exact causes are unknown, but it is believed that the condition may be linked to genetic causes or infections during pregnancy.

Factors that may play a role in the disruption of  the development of the corpus callosum include:

• Brain cysts that prevent normal growth of the corpus callosum
• Genetic abnormalities
• Heavy alcohol use during pregnancy
• Viruses and infections during pregnancy

Some research suggests that the condition results from disruptions in specific types of glial cells that play a part in the formation of the corpus callosum during a critical period of gestational development.

Many people with agenesis of the corpus callosum can function with minimal impairment. Others experience more significant challenges, which may include being blind, deaf, unable to communicate, or unable to walk. 

Other Conditions

Other conditions that may result from damage to the corpus callosum include:

• Pseudobulbar palsy: Affects the muscles of the face and tongue, leading to difficulty swallowing, speaking, and chewing
• Speech and movement ataxia: Lack of coordination of voluntary movements
• Alien hand syndrome: Involuntary hand movements without awareness or cognitive control

Corpus Callosotomy Can Damage the Corpus Callosum

The corpus callosum is sometimes severed during a procedure known as a corpus callosotomy. Some people with epilepsy may have this procedure to treat seizures when anticonvulsant medications have failed to help.

Can You Repair the Corpus Callosum?

The corpus callosum cannot be repaired or replaced if it is damaged or does not develop properly. However, rehabilitative interventions may help people overcome the impact of damage and improve functioning. This is thanks to neuroplasticity, or the brain's ability to rewire itself to restore functioning after an area of the brain has been damaged. 

Interventions that may help include:

• Speech therapy
• Cognitive therapy
• Physical therapy
• Occupational therapy

For example, speech therapists can help people with exercises focused on improving communication.

One case report found that a speech and language intervention effectively increased vocabulary, word combinations, and imitation abilities in a child with agenesis of the corpus callosum.

How to Keep Your Corpus Callosum Healthy

While there are currently no treatments to restore or repair a damaged or undeveloped corpus callosum, there are some strategies you can use to keep your brain healthy.

Practice Using Your Non-Dominant Hand

Try utilizing your non-dominant hand more frequently when writing, drawing, and eating.

Meditate

Practicing meditation has numerous health benefits, and there is some evidence that it may improve the health of your corpus callosum. Some research suggests that long-term meditators were more likely to have a thicker corpus callosa than non-meditators. According to researchers, this might be because nerve fibers are more myelinated, or more coherently orientated.

Build Your Bilateral Coordination

During childhood, engaging in activities that involve crossing the midline (or seamlessly coordinating movement between one side of the body and the other) plays an important role in development. Kids typically begin displaying this ability by six months of age and have mastered it by the age of eight or nine.

Activities that can help strengthen the corpus callosum in children include crawling, reaching for toys, and kicking a ball.

Practicing such skills later in life may also help strengthen your motor skills and improve communication between the brain hemispheres. Yoga is an excellent activity that requires bilateral movement coordination and can strengthen these midline crossing skills.

Keep Your Brain Healthy

Other things that you can do to protect your brain and keep your corpus callosum healthy include:

• Stay mentally active: Focus on stimulating activities that challenge your brain. Those most beneficial to the corpus callosum are those that require both hemispheres of the brain, which might include solving puzzles, juggling, learning a musical instrument, and solving math problems.
• Control your stress: Look for ways to lower your stress and incorporate relaxation techniques such as deep breathing, meditation, and progressive muscle relaxation.
• Improve your sleep: Sleep plays a vital role in brain health. Research has found that sleep quality is the most significant predictor of mental health and well-being. Strategies that can help improve your sleep quality include limiting caffeine and alcohol intake in the afternoon and evening, creating a restful sleep environment, and avoiding blue-light-emitting devices for 30 minutes before bedtime.
• Get regular exercise: One systematic review of both animal and human studies found that aerobic exercise and associated improvements in cardiovascular fitness are associated with improved function and integrity of the corpus callosum.