Epilepsy Surgery May Lead to Decline in word-finding as well as Memory
People who undergo epilepsy surgery should be counselled about a potential decline in their word-finding ability, according to a study published in the scientific journal, Neurology.
Before a person undergoes left temporal lobe surgery for drug-resistant epilepsy, their doctor will discuss with them the risk of subsequent memory problems. However, not much attention has been given to the effects of surgery on word-finding (also known as naming).
During the study, researchers at the University of Pittsburgh wanted to explore how changes in word-finding ability after surgery vary depending on the region of the brain that is operated on. To do this they looked back at records from 875 adults who underwent surgery (421 on the right side of the brain and 454 on the left side of the brain) for drug-resistant epilepsy.
Of the 875 subjects, 763 had temporal lobe surgery, 87 people had frontal lobe surgery and 25 people had surgery in the back of their brain. All completed an assessment called the Boston Naming Test, which is designed to measure a person’s ability to name objects from line drawings, before and after their surgery.
The findings showed that 41% of people who had left TLES experienced a decrease in word-finding ability, compared with 10-12% of people who had surgery of other areas on the left side of the brain. A decline in word-finding was rarely seen (only in 5%) amongst those who had surgery on the right side of the brain.
Looking at the data more closely, the researchers found that seventeen percent of people who underwent left TLES had what are considered to be substantial declines in word-finding. They also found that a decline in word-finding after left TLES was associated with a later age of epilepsy onset, an older age at the time surgery and higher word-finding ability prior surgery.
The authors have created a decision tree to assist clinicians in identifying those at a low, moderate or high risk of word-finding decline, and help them to counsel people about the risk of word-finding decline after left TLES.
“Development of risk models to predict naming outcome, akin to those that have been developed for memory, are needed to improve preoperative counselling for patients considering epilepsy surgery,” they note.
Authors: Dr Özge Özkaya and Delphine van der Pauw
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