Long Term Effects of Epilepsy Surgery
Most research to date has focused on the short-term outcomes of epilepsy surgery in children. Dr. Mary Lou Smith’s research looks at the long-term outcomes of surgery in children with drug-resistant epilepsy – where seizures persist despite taking medications. She has published a series of research studies looking at two groups of people with drug-resistant epilepsy – one group that underwent epilepsy surgery in childhood and another that did not – measuring outcomes at a follow-up period of 4-11 years later. In this series of studies, it was found that patients who had surgery achieved seizure freedom faster and used fewer anti-seizure medications at follow-up 1-8. But what did this research find about other health-related outcomes as these individuals developed into young adults?
Dr. Mary Lou Smith, Ph.D., is a Psychology Professor at the University of Toronto Mississauga. She is also a psychologist and researcher at The Hospital for Sick Children and a researcher with EpLink – The Epilepsy Research Program of the Ontario Brain Institute.
In this study, the patients with drug resistant epilepsy and their parents completed surveys about their symptoms of anxiety and depression.
→ Anxiety: Anxiety symptoms did not differ between individuals who did or did not have surgery, nor did it differ based on seizure status at follow-up.
→ Depression: 47% of individuals who continued to have seizures had symptoms of depression (as reported by their parents) compared to 15% of individuals who were seizure free.
Health-Related Quality of Life
The quality of life (QOL) was looked at through surveys that asked the individuals to rate how their epilepsy (past or present) influenced their current behaviours in a number of areas.
→ Individuals who were seizure-free at follow-up reported better QOL. Better QOL was associated with longer periods of being seizure free.
→ Individuals who had surgery reported that their past or present epilepsy had less of an impact on seizure worry and medication effects.
→ Symptoms of depression and anxiety significantly affected QOL.
Youth and parents completed surveys about behaviour, including questions about externalizing behaviour (e.g. acting out, aggression), attention problems, and bodily complaints (e.g. health symptoms without known cause).
→ All groups had improved behaviour over time, regardless of surgery or seizure status.
→ Individuals who were seizure-free at follow-up had fewer symptoms in all reported behaviours than individuals who continued to have seizures.
Youth were given memory tests that included recalling the details of stories, recognizing new faces, and learning and recalling word lists.
→ Memory did not improve over time in either the surgical or the non-surgical group. However, participants who eventually became seizure free had better performance at the start of the study on all tasks, and at follow-up for most tasks.
→ Individuals showed lower scores on the recall of word lists at follow-up compared to the start of the study, regardless of seizure or surgery status.
Study participants were tested on their language abilities, including picture naming, vocabulary, and letter fluency.
→ Among all patient groups, scores across language tasks were similar at the start of the study and at follow-up 4-11 years later.
→ Language skills did not depend on whether participants had surgery or not, but some aspects of language improved in individuals who were seizure-free at follow-up
Intelligence and Academics
Intelligence: Individuals were given a set of tests that examined various aspects of intelligence.
→ Seizure freedom – no matter if achieved through epilepsy surgery or medications – was linked to improved intelligence over time. Academics: Academic skills were measured in these groups with tests of reading, spelling and mathematics (arithmetic).
→ The test scores showed that 61% of individuals had low academic achievement and 23% of individuals showed academic under-achievement in at least one academic test at the start of the study and that these problems continued in the long term after surgery or continued drug therapy.
→ Reading and spelling scores did not change over time, but math scores declined in all groups.
→ Poor seizure control was associated with difficulties in spelling and math.
Education and Careers
Participants (or parents answering on their behalf) were asked to complete a survey about their current education, job status, income, and social functioning.
→ There were no significant differences between patients with and without seizures, except that more seizure-free patients with average IQs held a driver’s licence and lived independently.
→ Similar to the general population, 60% completed or were enrolled in postsecondary education, and 82% were employed or a student. However, fewer people with epilepsy earned an annual income of $10,000 or more when compared with the general population.
How does this help?
How does this research inform me about the risks and benefits of surgery for children?
It is important to make an informed decision when considering seizure surgery in youth (under 18 years of age). Speak to your healthcare provider, representatives from your Community Epilepsy Agency, others who have had surgery and look at the current research, such as the findings listed above. This will help you better understand the realities of epilepsy surgery, what to expect after, and whether it is right for you.