Small study finds physical evidence for 'chemo brain'
Chemotherapy can trigger measurable physical changes in brain function linked with memory loss and lapses in concentration, a small study from the US suggests.
Doctors and patients use the term 'chemo brain' to describe the mild cognitive impairment sometimes experienced by patients undergoing chemotherapy for cancer treatment.
US researchers used a combination of two imaging techniques: positron emission tomography (PET), and computed tomography (CT), which displays the body's anatomy and structure - to find evidence of 'chemo brain'.
The findings were presented at the annual meeting of the Radiological Society of North America (RSNA).
"The chemo brain phenomenon is described as 'mental fog' and 'loss of coping skills' by patients who receive chemotherapy," said Dr Rachel A Lagos, from the West Virginia University School of Medicine, who led the study.
"Because this is such a common patient complaint, healthcare providers have generically referred to its occurrence as 'chemo brain' for more than two decades."
Martin Ledwick, head information nurse at Cancer Research UK, said that the phenomena of 'chemo brain' is sometimes reported by patients. But researchers have had difficulty working out whether it's a psychological response to the trauma of having cancer, or a direct physiological result of treatment.
Previous studies using magnetic resonance imaging (MRI) found small changes in brain activity after chemotherapy, but weren't definitive.
By using PET/CT in the latest study, researchers were able to assess changes to the brain's metabolism after chemotherapy, providing more evidence that the phenomenon was linked to treatment.
Dr Lagos and colleagues analysed PET/CT brain imaging results from 128 patients who had undergone chemotherapy for breast cancer.
The team used special software to help discern differences in brain metabolism before and after chemotherapy.
The results showed that there are specific areas of the brain known to be responsible for planning and prioritising that use less energy following chemotherapy.
"When we looked at the results, we were surprised at how obvious the changes were," Dr. Lagos said.
Martin Ledwick from Cancer Research UK said: "It's good to see research into the effects that chemotherapy might have on cognitive function. The more we understand about this condition the better placed we will be to help and support people with it."
Copyright Press Association 2012