SEATTLE, May 4 (UPI) -- "Chemo brain" a decline in mental and fine motor skills due to cancer and its treatment disappears for most patients after five years, U.S. researchers say.
Researchers at Fred Hutchinson Cancer Research Center in Seattle say powerful chemotherapy drugs that leukemia and lymphoma patients receive prior to hematopoietic transplantation -- bone marrow, peripheral blood stem cells or umbilical cord blood -- as well as medicines can impact motor and memory skills.
Study leader Karen Syrjala and colleagues identified 92 patients who had received bone marrow or stem cell transplant for chronic myeloid leukemia, acute leukemia, lymphoma or myelodysplastic syndrome -- an umbrella term for several "pre-cancerous" diseases in which the bone marrow does not function normally.
For comparison purposes, the patients were asked to nominate a case-matched control, such as a sibling or friend of the same gender and similar age. All were given memory and motor skills tests.
The study, published in the Journal of Clinical Oncology, found most patients made substantial improvement five years after their transplant, but mostly mild, neurocognitive dysfunctions remained at five years for twice as many long-term survivors -- 41.5 percent versus controls at 19.7 percent.
"However, contrary to expectations, neither motor dexterity nor verbal learning and retention improved between one and five years," the study says. "Deficits were most notable in motor speed and dexterity."