chemo brain
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Heather Von St. James has learned to write things down.

“It’s more than being forgetful. It’s almost as if parts of my memory are missing,” the 49-year-old Minnesota resident told Healthline.

Von St. James is referring to the long-term effects of the chemotherapy she had 12 years ago.

She’s talking about “chemo brain,” or cancer-related cognitive impairment (CRCI).

Three specialists from the National Cancer Institute (NCI) say it’s time to get to the root of the problem.

Todd S. Horowitz, PhD, is a cognitive psychologist and program director at the NCI’s Division of Cancer Control and Population Sciences.

In an article published in Trends in Neurosciences, Horowitz and his colleagues wrote that chemo brain is a “widespread problem for the increasing population of cancer survivors.”

Why so many questions linger

Chemotherapy may not be the only contributing factor.

It may also be that other treatments such as surgery, hormone therapy, and radiation play a role.

It may even have something to do with the cancer itself.

“Our understanding of the nature, causes, and prevalence of CRCI is hampered by a reliance on clinical neuropsychological methods originally designed to detect focal lesions,” wrote the researchers.

Neuropsychological testing involves interviews and standardized tests designed to evaluate problems in several cognitive areas.

Patients with CRCI typically score in the low-normal range.

But that doesn’t say anything about how they function outside of a structured test.

And it doesn’t provide specifics on the processes involved in task performance.

Among other problems, the researchers say the subjective and objective measurements of cognitive impairment are not well-correlated.

They suggest it should be a priority to develop new measures of cognitive difficulties specific to people with CRCI.

They call for more cooperation and collaboration between neuroscientists and clinical researchers who study and treat CRCI.

Why it matters

There are more than 15 million cancer survivors in the United States. That number is expected to rise to more than 20 million by 2026.

One of the mysteries of chemo brain is just how many cancer survivors have it. Estimates vary from 17 to 75 percent.

Cancer survivors describe problems with concentration, short-term memory, multitasking, and finding words.

These issues, particularly those involving memory, become a quality-of-life issue. It can interfere with survivors’ ability to get back to their precancer careers and activities.

Dr. Cary Presant is a staff physician in the department of medical oncology at City of Hope and a practicing hematologist and medical oncologist in Southern California.

Presant told Healthline that some of his patients have told him they have chemo brain.

“They already know this is something that can happen. I hear this in about 30 to 40 percent of my patients. That’s not a small fraction at all, and they really feel distressed. It starts us on a quest to figure out what’s going on so we can help patients have a better quality of life,” he said.

Presant conducts a variety of tests to make sure there’s no evidence of metastasis or problems such as bleeding in the brain or stroke. Among the other things, he tests for B12, calcium, and magnesium levels.

“If there’s no other problem, we say this is probably a side effect of chemo or hormone treatment and we need to see what we can do,” said Presant.

Some cancer survivors get over chemo brain when treatment ends.

Others, like Von St. James, are still dealing with it more than a decade later.

She doesn’t recall her doctors mentioning chemo brain at the time of her treatment for mesothelioma. In fact, she didn’t even notice the symptoms until her treatment was complete.

“The initial impact wasn’t terrible because I was still just trying to figure everything out. But as time went on, I realized that something certainly wasn’t right and that my brain wasn’t working like it had prior to chemo. I didn’t know why at the time, nor did I really understand the reason behind the gaps in my memory,” said Von St. James.

Currently, there are no clear answers to why some people get chemo brain, how long it will last, or the best ways to address it.

Coping with chemo brain

Von St. James says part of her coping strategy includes making lists and using calendars and reminders.

“I’m still trying to navigate this new normal and I think that is the trick. You have to figure out the right fit for you,” she said.

Presant, author of the book Surviving American Medicine, said that exercise is an effective way of dealing with mental fog.

He also said patients should ask about medications that can increase attention span and focus.

“Some people have benefited from antidepressants in small doses. We usually refer for follow-up with a psychologist or neurologist to make sure we haven’t overlooked anything,” he said.

As part of a study at City of Hope, doctors are looking at brain function before, during, and after chemotherapy and hormonal therapy.

“We also have a control population of those who are not getting that so we can see what happens with time to normal individuals not given these therapies. We know that roughly 5 to 10 percent of normal people without cancer will pop up with some of these symptoms. It can be a reaction to stress, nutrition, hydration, etc.,” said Presant.

Communication is key

It took Von St. James years to bring it up with her family doctor.

“I honestly didn’t know I had chemo brain until talking with another patient,” she said.

That’s why she advises cancer patients to talk to each other.

The process begins with good communication, said Presant.

“I recommend to patients that they come in with a list of symptoms and questions. Write them down and bring another person with you,” he said.

Presant says the recent published paper did a good job of focusing on the kinds of research that should be done.

But in the meantime, his focus is largely on how to help patients now.

“One thing about this is how frightening it can be. We know if you give patients choices, they will trade length of life for better quality of life and maintaining the ability to think,” said Presant.

“That means doctors have to be aware that while trying to extend patients’ lives we have an equal — or even greater — obligation to take care of symptoms like this that interfere with quality of life. And to focus on creating the proper care team to face this frightening situation,” he explained.

“That means psychologists, neurologists, oncologists, nurse practitioners, primary care physicians — this is the team. It also includes the patient and the patient’s family —everybody has got to play their role,” said Presant.