Towards the Cutting Edge – Epilepsy Surgery at KHSC

Written by Tarrah Ethier, MSc., PhD Candidate and TMED 801 Student.

On March 9th Dr. Garima Shukla delivered an engaging and informative lecture at Medical Grand Rounds. Dr. Shukla is a professor in neurology at Queen’s University, specializing in epilepsy and sleep medicine. Her rounds, titled “Towards the Cutting Edge – Epilepsy Surgery at KHSC”, discussed drug-resistant epilepsy, epilepsy surgery and the wonderful initiative that the neurology department has undertaken to provide epilepsy surgery for patients served by the Kingston Health Sciences Centre (KHSC).

Epilepsy is a neurological condition that is characterized by the presence of reoccurring seizures, which are a disruption in normal brain activity. Seizures can be classified into three main categories based on their origin: generalized, focal and epileptic spasms1. The clinical manifestations of these different categories are dependent on the region of the brain that is involved in the seizure. Further, these clinical manifestations can vary in duration and the involvement of motor symptoms, such as sustained rhythmic jerking. In Ontario, a physician will start examining diagnostic criteria if their patient has had two or more seizures, as this is a World Health Organization guideline2. Dr. Shukla explained that epilepsy in most patients can be fully treated or reasonably managed with anti-epileptic medication. However, approximately one in three patients with epilepsy are drug-resistant or refractory3. Drug-resistance is declared when a patient remains burdened by seizures even after trialling two appropriately selected anti-epileptic drugs4. In cases like this, other interventions, or treatment methods, such as surgery, are necessary to achieve seizure freedom.

The degree to which a center can treat epilepsy is dependent on its classification. In Ontario, there are two types of epilepsy centers, district and regional5. Healthcare practitioners at district epilepsy centers (DECs) can treat patients through prescription of medications and assess patient candidacy for epilepsy surgery. Healthcare practitioners at regional epilepsy centers (RECs) can prescribe medications and assess surgery candidacy, as well, but are additionally able to perform epilepsy surgeries. There are 4 DECs, including the KHSC, and 3 RECs in Ontario. These classifications unfortunately limit the care in which DECs can provide to patients, through resource allocation. Dr. Shukla and her team at KHSC recognized the burden that this places on refractory patients and pushed to offer surgery for this cohort. To date, the surgeries have been incredibly successful, as the team has left all surgical patients’ seizure free. Dr. Shukla recognizes that as they are still early in this surgical offering, these numbers will likely change as time advances.

Their success rate with surgery is in part attributed to the scrutiny placed on accurately assessing surgical candidacy, which requires individualized precision medicine. This typically involves taking a detailed neurological history, neuroimaging, video-EEG monitoring, and neuropsychological testing6. Candidacy is also determined by identifying a clear epileptogenic zone (EZ), as epilepsy surgery consists of resecting this small area in the brain. Dr. Shukla demonstrated the challenge of accurately identifying these epileptogenic zones, using her own refractory patient cases. She then cited her team and their collaborative efforts as the main factor behind their documented success with helping these patients. The EZ is defined as the area of brain cortex that is necessary for the clinical initiation of a seizure, as it encapsulates the seizure onset zone7. Removal of this zone is believed to provide seizure freedom8. The EZ is not localized to a single hemisphere or lobe, adding difficulty to its identification. The success of a surgery is also dependent on the resection location. For instance, Dr. Shukla stated that temporal lobectomies are the most common epilepsy surgery and have the best outcomes9.

After the rounds, Dr. Shukla sat down with students of the newest cohort of Translational Medicine (TMED) graduate program to further discuss how her lecture topic can help patients, how it has been discussed in the lay press and addressed EDII initiatives and, finally, how her career and education has led her to her current role. Specifically, we discussed the challenges with identifying epileptogenic zones using MRI, the implications of artificial intelligence on diagnosis, and epilepsy classification and management in women. We concluded with an overview of how Dr. Shukla has eagerly integrated her research and being “patiently impatient” with challenging patient care guidelines, into her practice.

On behalf of the TMED graduate students, I would like to thank Dr. Shukla for her stimulating grand rounds lecture and her inspiring discussions focusing on teamwork and keeping medicine patient-centered.

References:

1. Berg AT, Berkovic SF, Brodie MJ, Buchhalter J, Cross JH, van Emde Boas W, Engel J, French J, Glauser TA, Mathern GW, Moshé SL. Revised terminology and concepts for organization of seizures and epilepsies: report of the ILAE Commission on Classification and Terminology, 2005–2009.
2. Epilepsy; WHO, 2023
3. Kwan P, Schachter SC, Brodie MJ. Drug-resistant epilepsy. New England Journal of Medicine. 2011 Sep 8;365(10):919-26.
4. Kwan P, Arzimanoglou A, Berg AT, Brodie MJ, Allen Hauser W, Mathern G, Moshé SL, Perucca E, Wiebe S, French J. Definition of drug resistant epilepsy: consensus proposal by the ad hoc Task Force of the ILAE Commission on Therapeutic Strategies.
5. Bowen JM, Snead OC, Chandra K, Blackhouse G, Goeree R. Epilepsy care in Ontario: an economic analysis of increasing access to epilepsy surgery. Ontario health technology assessment series. 2012;12(18):1.
6. Miller JW, Hakimian S. Surgical treatment of epilepsy. Continuum (Minneap Minn). 2013 Jun;19(3 Epilepsy):730-42.
7. Jobst BC, Cascino GD. Resective epilepsy surgery for drug-resistant focal epilepsy: a review. JAMA. 2015 Jan 20;313(3):285-93.
8. Rosenow F, Lüders H. Presurgical evaluation of epilepsy. Brain. 2001 Sep;124(Pt 9):1683-700.
9. Sperling MR, O'Connor MJ, Saykin AJ, Plummer C. Temporal lobectomy for refractory epilepsy. JAMA. 1996 Aug 14;276(6):470-5.