I. Abstract
Chemo brain is a form of cognitive impairment that is found in 25-80% of patients who have received chemotherapy. Studies show that the syndrome is related to an increase in inflammatory cytokines and the problem can last for 10 years or more. No traditional therapies are identified to treat chemo brain. Natural approaches, which are often ignored by medical experts, have known effects in the prevention and treatment of dementia. These include gingko biloba which improves circulation and early dementia by producing anti-inflammatory cytokines and dietary changes. Diets high in fruits and vegetables are known to decrease the risk of dementia while omega-3 fatty acids are known to be anti-inflammatory. These are the keys to prevention and treatment of chemo brain.
II. Introduction
Loss of memory or dementia is one of the greatest fears of aging people. This affliction is by no means limited to the elderly. Cancer survivors can also develop loss of memory. Loss of memory in cancer patients has different names; dementia, cognitive dysfunction, but the most recently coined terms chemo brain and chemo fog suggest chemotherapy may play a major role in its cause. What is chemo brain and how can it be treated? The problem has been recognized for a decade but these important questions have only recently been the focus of experts in the field. Although research into this condition is ongoing and unfortunately many questions remain unanswered and we will discuss that it is not only found in patients who have received chemotherapy.
III. Definition
Chemotherapy causes many acute symptoms such as low blood counts, nausea, hair loss or diarrhea. These often resolve soon after the chemotherapy is stopped. There are however other symptoms that are more chronic. These include fatigue and loss of memory or chemo brain. Common complaints described in studies include not only poor memory but an inability to concentrate at work or juggle multiple tasks. This is very distressing to a patient who has already had to endure a diagnosis of cancer and the physical effects of surgery, chemotherapy or radiation therapy. Although depression, anxiety, and anemia can contribute to these problems, the symptoms of chemo brain remain after these other problems have been corrected.
Chemo brain is more than a subjective complaint. Measurable abnormalities can be found on formal neuropsychological tests and measures. These tests can evaluate a variety of parameters including attention and concentration, verbal memory, visual memory, visual-spatial and speed of information processing. Published studies have demonstrated a broad range of cognitive deficits thus identifying this as an authentic medical problem.
IV. Incidence
Review articles on chemo brain have demonstrated that this is a common problem. There have been approximately eleven groups that have published reviews on this subject mostly in patients with breast cancer but others are also included. Symptoms of chemo brain can be found in 25% to 80% after their therapy. Interestingly, chemo brain has been found in 35% of patients before chemotherapy is ever given suggesting that there may be a predisposition to the illness in addition to effects produced from the cancer itself and possibly surgery. This appears to be a problem that is more complex but far reaching. Many of the 10 million cancer survivors have received surgery, radiation and chemotherapy and 35% to 80% may exhibit some cognitive dysfunction.
V. Etiology
The cause of chemo brain is thought to be the result of vascular, metabolic, or inflammatory changes in the brain. Sophisticated radiology scans have found interesting and provocative changes in the brain. Magnetic resonance imaging (MRI) has demonstrated widespread decrease in gray matter of the brain suggesting atrophy of the brain related to a toxic effect of chemotherapy. More recently, researchers have measured metabolic activity in the brain with positron emission topography (PET) scanning. Studies utilizing PET scans have demonstrated decreased metabolism in the frontal cortex, prefrontal gyrus, Broca's area and their corresponding contralateral areas in the brain. Interestingly, these areas are responsible for memory and concentration. When patients were given simple memory tests to perform, abnormalities in these areas were again demonstrated whereas there were no abnormalities found in people without cancer.
The cause of the metabolic abnormalities in the brain may very well be the same problem that has been implicated in Alzheimer's Dementia, namely inflammatory cytokines (IC's). Inflammatory cytokines are substances secreted by the immune system to help fight infections. When IC's are chronically elevated they lead to a variety of chronic diseases such as heart disease, cancer, strokes, chronic fatigue, rheumatoid arthritis and dementia. Multiple studies in both animal and human models have demonstrated the correlation of chemo brain with inflammatory cytokines. Although inflammatory cytokines do not consistently increase with the administration of chemotherapy, the presence is chemo brain is found when the inflammatory cytokines are elevated. Curiously, fatigue is also a common chronic complaint in cancer patients and inflammatory cytokines are also elevated in these patients.
VI. Therapy
The treatment of chemo brain should target the root causes. Of course, problems such as anemia, depression, infection, anxiety must all be addressed and treated. Methylphenidate or Ritalin has been recommended by some experts but it only treats the symptoms of the disease.
Since inflammatory cytokines seem to be a major contributing factor to the etiology of the disease, therapies aimed at decreasing these should be offered. Steroids such as prednisone or dexamethasone are commonly used to treat inflammatory diseases such as rheumatoid arthritis. There is no proof they are useful in chemo brain and some researchers have suggested they might cause chemo brain. Additionally, they have too many side effects to be useful for long term use. Non-steroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen have been found to be helpful in delaying the onset of dementia in patients with Parkinson's disease and Alzheimer's disease. This may be a possible therapy for chemo brain but is not likely to be a curative modality.
There are two therapies that are overlooked by modern medicine that can effectively treat dementia and chronic inflammatory cytokines these are gingko biloba and diet.
Gingko biloba has been used in traditional Chinese medicine for thousands of years. It has many beneficial effects including improving blood circulation which is helpful in patients with claudication. It has also been found to improve function in early dementia due to either vascular disease or Alzheimer's disease. Gingko improves circulation by increasing anti-inflammatory cytokines. Therefore it seems reasonable to suppose that gingko would be beneficial to patients with chemo brain since their form of dementia is caused by inflammatory cytokines.
Perhaps the most forgotten therapy to prevent and treat diseases is diet. Too often patients look for a pill to treat their illness when a change in diet can be very beneficial. The typical American diet is high in animal fats, trans-fats, corn oil, refined sugars, and carbohydrates and it lacks fruits and vegetables. This type of diet leads to an increased risk of heart disease, stroke, and cancer. We know that inflammatory cytokines play a major role in the etiology of these diseases. Multiple studies have shown that a diet rich in fruits, vegetables, and omega-3 fatty acids can prevent theses diseases by their anti-inflammatory and anti-oxidant actions. In many ways, we are causing the very chronic diseases that plague us.
The treatment or prevention of chemo brain is a simple process that focuses on the root cause of the dementia namely inflammation. We already know that certain diets and gingko can treat and prevent certain diseases caused by inflammatory cytokines. The most prudent approach to treating or preventing chemo brain is a diet rich in omega-3 fatty acids, fruits, vegetables, and gingko biloba.
Robert Avery MD, is a practicing oncologist in the St. Louis area. He has a keen interest not only in cancer care and therapy but also nutrition and how is helps prevent cancer. He is owner of Citrine Sun, an online company dedicated to helping cancer patients through every stage of their illness through education and natural supplements. An interesting newsletter and information about helpful supplements are available at his website, http://www.citrinesun.com Contact Dr. Avery through his email, AskDrAvery@citrinesun.com
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