Memory Loss and Brain Tumor Surgery

Jon I. McIver, M.D., an experienced neurosurgeon with The Minimally Invasive Brain and Spine Center at Mercy, responded to questions from ClinicSpots regarding memory loss and brain tumor surgery. Here are his insights:

How is memory loss related to brain tumor surgery?

Memory loss is a risk of brain tumor surgery, but the causes can be multifactorial, and not directly related to removing the brain tumor. One challenge is determining if a person truly has memory loss alone, or if there is difficulty creating and or retrieving information due to delirium.

A patient's age and predisposition to confusion and memory impairment is always something that should be considered. It is usually the case that the older a patient is, the less cognitive reserve they will have, and the more vulnerable to post-operative confusion they will be.

This is not always the case however. It depends upon the person. In addition to the process of surgery itself, the exposure to general anesthesia and being in an unfamiliar environment with new daily schedules can be disorienting.

If a person has dementia, and pre-existing memory impairment, their memory can definitely worsen following the stressors of surgery.

Other perioperative complications such as bladder infection can also disrupt a person's memory and thinking. In this case, memory impairment and delirium should resolve.

The medications used to treat a person following brain tumor surgery (such as pain medication and anti-seizure medication) can also affect memory.

There are cases when the team can predict the likelihood of memory loss after surgery, especially if the tumor is within or disrupting the memory circuitry. Testing of the strength of memory for each side of the brain can be done to understand how important memory structures are that might be disrupted or irritated with surgery. This assessment is called WADA testing and is paired with Neuropsychological evaluation.

Psychological stressors and diagnoses can also complicate the detection, quantification and qualification of memory problems.

Is memory loss after brain tumor surgery permanent?

Permanent memory impairment following surgery is a rare complication.

The duration of post-operative memory impairment depends upon the cause. If memory circuitry is interrupted or disrupted by tumor or surgery to remove the tumor, or if there is swelling due to surgery, memory impairment can be permanent or take a very long time to improve.

If a person has delirium as the cause of memory impairment, or infection, then improvement is anticipated.

What other neurological symptoms can occur after brain tumor surgery?

The possible symptoms are dependent upon the brain circuitry that might be affected by the brain tumor surgery. This includes all of the senses as well as movement and cognition.

What treatments or therapies are available for memory loss after brain tumor surgery?

If a person experiences memory loss following brain tumor surgery, the mainstay of treatment is usually Speech and Occupational Therapy. Outpatient Neuropsychology assessment is also a good resource.

What is the success rate for memory improvement after brain tumor surgery?

There are many variables that contribute to the risk of and recovery from memory impairment after brain tumor surgery. Much depends upon the patient's cognitive performance prior to surgery, where the brain tumor is located, what medication a person is taking, and whether the patient experiences complications such as infection in the post-operative period.

Can memory loss after brain tumor surgery be prevented or reversed?

The risk of memory loss after brain surgery can be decreased by understanding risk factors for delirium, understanding if the patient has cognitive vulnerabilities, determining if the tumor is within or close to brain circuity important for memory, and involving therapy teams and family members as early as appropriate. If possible, a good preparation for decreasing memory loss is understanding if the tumor is within or close to memory circuitry and having a discussion with the patient and family on what the risks of surgery are, and what the recovery process entails.

Dr. Jon McIver is board certified by the American Board of Neurological Surgery. A Fellowship-trained neurosurgeon with expertise in a variety of conditions such as brain tumors and brain trauma, degenerative spine disorders and spine fractures, Dr. McIver uses computer technologies and advanced image-guided surgery systems, including the Stealth Navigation and O-arm® Mobile Surgical Imaging System.