Unbeknown to most, epilepsy is one of the most common neurological conditions. Despite the prevalence of multiple anti-epileptic medications, around 30% of individuals with epilepsy fail to achieve seizure control through their medication regime. In fact, research suggests that once an individual is consuming 2 anti-epileptic medicines, the likelihood of achieving complete seizure control with each additional medication is around 5-10% per year. These individuals are said to have refractory or drug resistant epilepsy.
This population of individuals with drug-resistant epilepsy is thus faced with numerous issues - there is of course the epilepsy itself, which results in cognitive, behavioural and psychological issues; there is the anti-epileptic regime which can also result in heightened irritability, increase risk of attentional issues and lead to weight gain (among other things). And lastly, there is the case of social issues arising secondary to the individual’s neurological condition - people with epilepsy are often stigmatised, discriminated against and their uncontrolled medical condition may make it difficult for them to lead an independent life.
Thinking beyond medicines
In the event that medication begins to show limited effectiveness with regard to seizure control, there are other options to be considered. Some individual’s seizures may be stemming from a structural abnormality in the brain. In some of these cases, surgical removal of the abnormal structure may result in significant seizure relief.
If treatment with anti-epileptic medication fails to provide adequate seizure relief, an individual may be considered for a surgical work up. There is a large amount of data to suggest that some epilepsy syndromes may be especially amenable to high rates of seizure freedom through a surgical procedure; temporal lobe epilepsy, being the most common candidate.
The purpose of surgery broadly speaking, is to improve the individual’s quality of life. Based on the impact on seizure freedom however, surgical solutions for epilepsy can be broadly divided into 2 categories:
- A curative surgery, where the primary goal of the surgery is to offer the person seizure freedom AND
- A palliative surgery, where the primary goal of the surgery is to reduce the seizure burden of the individual. Seizure freedom is not expected as part of this class of surgeries.
There are however clear criteria that must be fulfilled before a surgical option is considered. For starters, the person must have drug-resistant epilepsy. In other words, the individual continues to experience seizures despite being trialled on at least 2 different anti-epileptic medications. Secondly, the benefits of conducting surgery must outweigh the risk involved. For instance, good seizure control with a resultant amnesia (and thus poor quality of life), is not a good overall outcome. In this case, the risk is likely to outweigh the benefits. Determining surgical candidacy is thus not a decision to be taken likely. It is no surprise then that the typical process of epilepsy surgery work up is a comprehensive one and involves a multidisciplinary team comprised of a neurosurgeon, epileptologist, neurologist, neuroradiologist and a neuropsychologist.
While the notion of brain surgery is a scary one, in some cases of drug-resistant epilepsy, surgery might offer a good solution to gain seizure control. In fact, the benefits of surgery may stem beyond this to include a drop in medication. For patients who stop having seizures after surgery, a neurologist will gradually wean them off anti-epileptic medication. As their dosage reduces, the extent of side effects arising from these medications also reduces.
Age is no bar with regard to determining candidacy for epilepsy surgery. Infants, children, adolescents, young adults, middle aged individuals, the elderly - anyone undergoing a thorough workup by a comprehensive team may be deemed fit to be a surgical candidate.
The typical investigations one undergoes as part of this workup and the function of each is described below:
- Long-term telemetry or video EEG monitoring: As the name suggests, a video EEG serves 2 functions - it records a video of the person experiencing a seizure while simultaneously obtaining electrophysiological data. In other words, it seeks to determine where in the brain the abnormal electrical activity is arising from
- Brain MRI: This provides the team with a picture of the brain to help determine the presence/absence of any structural abnormality.
- FDG-PET: This is a functional neuroimaging investigation which speaks to the metabolic activity of different brain regions. Lower activity in a region at rest may be suggestive of a suspicious area.
- Neuropsychological assessment: Lasting 3-4 hours, a neuropsychological assessment helps determine whether the functions subserved by different parts of the brain (e.g. memory, reasoning etc) are preserved or deficient. The profile of results obtained can help identify which part of the brain may be affected as a result of the epilepsy and also helps clarify the risks/benefits associated with a potential surgery.
Apart from seizure relief, there are considerable economic benefits associated with surgery. While families may incur a one-time cost, studies suggest that in the long run, surgical procedures end up being a much more cost-effective option. Expenses incurred by families of children with intractable epilepsy typically include not just the cost of medicines but also recurrent hospitalisations, secondary expenses on account of falls etc, as well the indirect costs associated with withdrawal of caregivers from the workforce.
For many individuals with epilepsy, surgical intervention can act as a new lease of life. Unfortunately, despite its many benefits, epilepsy surgery is heavily under-utilised in a nation like India. One of the main reasons for this is the lack of awareness of surgery as an option in epilepsy treatment. While every individual with drug-resistant epilepsy may not be a surgical candidate, undergoing an evaluation to explore the possibility of the same would help ensure that patients are receiving the highest possible level of care from their treating physician. In fact, as per some estimates, up to 70 - 80% of individuals with refractory epilepsy may be surgical candidates. So this epilepsy awareness month, let’s be cognisant of surgery as a possible solution to epilepsy and consider it early on the course of refractory epilepsy. Your decision could make all the difference!
- Prof. Deepa Bapat, Adjunct Faculty – Psychology
- Dr Nilesh Kurwale, Epilepsy Surgeon, Coordinator for Bajaj Allianz Centre for Epilepsy, Deenanath Mangeshkar Hospital Pune.