Most studies that evaluate long-term cognitive function after epilepsy surgery take aim at memory and intelligence, but a recent study by researchers at the Hospital for Sick Children in Toronto focused on the language abilities of children who underwent surgery.
Results from the study “Predictors of language skills in the long term after pediatric epilepsy surgery,” published in the scientific journal Epilepsy and Behaviour, showed that the surgery had no impact on language.
The identification of long-term effects on cognitive ability after surgery is important because it provides doctors and families with important information for future decisions regarding the invasive procedure as an epilepsy treatment. In the recent study, researchers evaluated the language skills of patients who underwent or were considered for epilepsy surgery 4–11 years earlier.
Included in the study were 97 patients of whom 61 eventually underwent epilepsy surgery. Following recruitment, the patients completed standardized tests to assess language skills. The tests included picture naming, vocabulary, letter fluency, semantic fluency, and intelligence. Tests were performed at enrollment (baseline) and 7 years later, on average.
Researchers compared the data between a range of population groups such as surgical versus non-surgical, pre-surgical versus post-surgical, and seizure freedom versus seizure continuation. Language performance at baseline and follow-up of those who underwent surgery was similar to those who did not have surgery which suggested that surgery itself did not harm language skills, according to the results.
In contrast, language skills were linked with seizure control because researchers found that children who spent a larger proportion of their lives free of seizures generally performed better at language tasks. Few patients showed meaningful improvements at individual levels after seizures became controlled. The observations suggested that uncontrolled seizures may hinder the long-term capacity for improvement even in the absence of seizure activity.
Researchers also found that older age at epilepsy onset, higher IQ, and higher baseline scores were associated with better performances on all language tasks. Additionally, patients who presented a localized one-sided seizure tended to do better in some of the languages tasks at follow-up.