According to researchers, chemotherapy brings about long lasting modifications in the brain metabolism and blood flow and could be responsible for the mental fog and confusion in several cancer survivors.
The study conducted by researchers at the University of California, Los Angeles, revealed inferior metabolism in the important region of the frontal cortex in women who had undergone chemotherapy 5-10 years ago.
A spike in blood flow to the frontal cortex and cerebellum was also observed in these women while executing memory tests. This shows a swift leap in activity level.
"The same area of the frontal lobe that showed lower resting metabolism displayed a substantial leap in activity when the patients were performing the memory exercise," said Daniel Silverman, the UCLA associate professor who led the study.
"In effect, these women's brains were working harder than the control subjects' to recall the same information," he said in a statement.
According to the statement, experts calculate approximately that not less than 25% of the chemotherapy patients are affected by chemo brain. The latest study by the University of Minnesota reported an 82%.
"People with 'chemo brain' often can't focus, remember things or multitask the way they did before chemotherapy," Silverman said. "Our study demonstrates for the first time that patients suffering from these cognitive symptoms have specific alterations in brain metabolism."
This study, published on Thursday in the online edition of Breast Cancer Research and Treatment, was conducted on 21 women who had undergone surgery to remove breast tumors. Of them, 16 had received chemotherapy and the rest had not.
Positron Emission Tomography (PET) scans were used to compare the brain function of these women with those of 13 women without breast cancer or chemotherapy.
A special camera that follows the progress of an injected radioactive tracer produces an image of the parts of the body in PET.
The scans were used to follow the brain metabolism at resting state and the blood flow to their brains during short-term memory tests.
Silverman said, "The findings suggest PET scans can be used to monitor the effects of chemotherapy on brain metabolism. Since the scans already are used to monitor patients for tumor response to therapy, the additional tests would be easy to add. "
The statement revealed that breast cancer is the most widespread cancer among women.
Around 2,11,000 new cases are reported every year.