How a Corpus Callosotomy Helps Treat Epilepsy

What Is the Corpus Callosum?


The corpus callosum is the part of the brain that connects the right and left hemispheres. The hemispheres are the halves of the brain, and the cerebral cortex is composed of two hemispheres, the right hemisphere and left hemisphere.

The corpus callosum physically and functionally connects the hemispheres, which means that it facilitates communication between the right side of the brain and the left side of the brain.

This interaction allows the mind to integrate thoughts, ideas, and awareness for optimal brain function. The rapid neural associations enabled by the corpus callosum are largely responsible for providing us with the ability to seamlessly synchronize activities between the right and left sides of the body.

Surprisingly, the corpus callosum, while very important, is not essential for survival. Some individuals lack a perfectly intact corpus callosum, either as the result of a birth defect or due to a surgical procedure called a corpus callosotomy. Those who do not have a perfectly formed corpus callosum as the result of a birth defect may have learning problems or neurological problems that can range from mild to severe.

What Is a Corpus Callosotomy?

A corpus callosotomy is a type of brain surgery that involves actually severing the corpus callosum to physically and functionally disconnect the hemispheres of the brain, preventing communication between the right and left hemispheres.

This diminished neural communication between the two sides of the brain can prevent certain types of seizures from becoming intense and may decrease the frequency of certain types of seizures.

This procedure is one of several surgical treatment options for people who have refractory epilepsy, also called intractable epilepsy, which is epilepsy that does not improve with anti seizure medication.

Typically, a highly trained neurosurgeon performs a corpus callosotomy. If you have been told that you might need to have a corpus callosotomy, then you will likely undergo a series of tests prior to your procedure, such as an electroencephalogram (EEG) and a brain MRI.

There are several methods for performing a corpus callosotomy, including minimally invasive techniques. Your surgical team will evaluate your situation to determine the best approach for you.

Side Effects

There are several side effects of corpus callosotomy. These consequences are typically the result of the diminished interaction between the left and right hemispheres of the brain. A corpus callosotomy is a procedure that is not reversible.

Side effects include trouble with naming and recognizing objects that are seen in one side of vision or out of one eye. For example, a person who has had a corpus callosotomy might see something on the left or right side and could be unable to recognize it or name it, even if it is a familiar object.

The most well known consequence of a corpus callosotomy is called alien hand syndrome. This is a syndrome characterized by the inability to recognize and purposely control a body part, such as the hand.

Some people with alien hand syndrome are aware that they have the syndrome and still cannot identify their own hand. If you have alien hand syndrome, your hand or arm may move on its own, making gestures and actions that do not have an understandable purpose.

A Word From Verywell

If you have had epilepsy that does not improve with medication, your doctor may suggest a corpus callosotomy. Not everyone who has difficult to control epilepsy is a candidate for a corpus callosotomy. Because this is a fairly uncommon procedure with known side effects, you should expect a detailed and careful medical and surgical evaluation before you and your medical team reach a conclusion about whether or not it is the right procedure for you.

If you or your child has a corpus callosotomy, you will likely need to maintain close follow-up with a team of doctors, including neurologists and neurosurgeons, for the rest of your life. Many people who have had neurosurgical procedures such as a corpus callosotomy are able to lead productive lives with significantly better function than they had prior to the procedure.

When you have a rare condition such as alien hand syndrome, it may also help you to find a support group of people who have been through a similar situation, so that you will know exactly what to expect and how it will impact your life.


Singh H, Essayed WI, Deb S, Hoffman C, Schwartz TH, Minimally Invasive Robotic Laser Corpus Callosotomy: A Proof of Concept,, Cureus. 2017 Feb 10;9(2):e1021