Surgery affects memory, concentration

STOCKHOLM, Sweden, Jan. 5 (UPI) -- Patients undergoing surgery and anesthesia can develop a decline in memory and learning long after the procedure, researchers in Sweden say.

Lars I. Eriksson, professor of anesthesiology and intensive care at Karolinska Institutet in Stockholm and Karolinska University Hospital, said post-operative cognitive decline is particularly common in the first week after surgery, but in 10 percent of adult patients it can persist for as long as three months.

Although the reason for the impairment of memory and learning capacity remains unclear, it is known that patient-related factors such as age, morbidity and pre-existent cognitive impairments are a significant risk factor, Eriksson said.

"In recent years, animal studies have shown that surgery itself can cause distinct changes in the parts of the brain involved in cognitive functions, as the inflammatory response to surgery leads to neuroinflammation-related disruption to cognitive abilities," Eriksson said in a statement.

The study, published in the Annals of Neurology, found a side-effect of surgery is damage to the blood-brain barrier -- a separation of circulating blood and the brain extracellular fluid in the central nervous system.