Key Points:
- Nearly 20 years ago, Peter Carlen, MD received a one-year grant from CURE Epilepsy that served as a catalyst for his research into seizure detection and electrical neurostimulation. One of the companies Dr. Carlen established continues the work in seizure detection and is currently building on his lab’s recent identification of a biomarker for sudden unexpected death in epilepsy (SUDEP).
- For more than 20 years, through investing in paradigm-shifting ideas, CURE Epilepsy has enabled scientists to discover insights essential for advancing the understanding of epilepsy and moving us closer to a cure.
Deep Dive:
Dr. Carlen began his career as a general neurologist at the University of Toronto. He founded the Epilepsy Program at the Toronto Western Hospital 25 years ago and is now one of its staff epileptologists. With his 2002 funding from CURE Epilepsy, he collaborated with mathematician and engineer Dr. Berj Bardakjian and a student with a background in physics, Dr. Houman Khosravani, to investigate the promise of computation and engineering techniques to understand epileptic networks and to ultimately develop the ability to disrupt them.
The work facilitated by his CURE Epilepsy-funded grant has contributed substantially to prediction and treatment of epilepsy. The researchers first published a paper documenting arrest of seizure activity with brief, low frequency electrical pulses delivered to brain tissue [1] and later published two additional papers on electrical neurostimulation [2,3]. Since these initial studies, Carlen’s lab has progressed to more advanced testing paradigms with modified parameters to make the pulses more akin to what actually happens in the brain. Significantly, this newer protocol appears to result in better seizure control than the more traditional pattern of repetitive square pulses.
Perhaps some of the most frightening and challenging aspects of epilepsy are seizure unpredictability and the potential for SUDEP; thus, seizure and SUDEP forecasting remain priorities in epilepsy research. Dr. Carlen’s current research also focuses on the brainstem, a small area at the base of the brain located just above the spinal cord, that regulates functions such as breathing and heart rate. Hypothesizing that SUDEP reflects disturbances in the brainstem, Carlen’s lab measured the electrical activity from this brain region in rats and discovered that seizures originating here led to cardiorespiratory arrest and death [4,5], important findings that continue to influence the field.
Since the initial research supported by their 2002 CURE Epilepsy grant, Carlen and Bardakjian have continued to collaborate, recently making a breakthrough that could reduce overall morbidity and mortality in epilepsy: they have developed a seizure alarm and identified SUDEP biomarkers in the unique electrical patterns of the electroencephalogram (EEG) [6]. They have since founded a company called Neurometrics Technologies to develop this technology further, with the goal of combining a wireless headset with complex computer algorithms capable of analyzing a patient’s EEG patterns to predict seizures and detect SUDEP biomarkers.
Carlen finds serving as the bridge between his patients in the clinic and the basic research in his lab especially rewarding. As an epileptologist, he witnesses firsthand the intense suffering endured by people with epilepsy and, as a scientist, he is in a unique position to develop more effective treatments with little to no side effects, a true cure.
CURE Epilepsy is proud to have played a role in advancing research by Dr. Peter Carlen and his colleagues, building hope for prevention and cures, and ultimately, a world without epilepsy.
Literature Cited
[1] Khosravani, H., Carlen, P.L., & Velazquez, J.L.P. The control of seizure-like activity in the rat hippocampal slice. Biophys. J. 2003; 84: 687-695.
[2] Chiu, A.W.L., Jahromi, S.S., Khosravani, H., Carlen, P.L. & Bardakjian, B.L. The effects of high-frequency oscillations in hippocampal electrical activities on the classification of epileptiform events using artificial neural networks. J. Neural Eng. 2005; 3(1): 9-20.
[3] Khosravani, H., Pinnegar, C.R., Mitchell, J.R., Bardakjian, B.L., Federico, P., & Carlen, P.L. Increased high-frequency oscillations precede in vitro low-Mg2+ seizures. Epilepsia 2005; 46(8): 1188-1197.
[4] Salam, M.T., Montandon, G., Genov, R, Devinsky, O., Del Campo, M., & Carlen, P.L. Mortality with brainstem seizures from focal 4-aminopyridine-induced hippocampal seizures. Epilepsia 2017; 58(9): 1637-1644.
[5] Lertwittayanon, W., Devinsky, O., & Carlen, P.L. Cardiorespiratory depression from brainstem seizure activity in freely moving rats. Neurobiol. Dis. 2020; 134: 104628.
[6] Grigorovsky, V. et al. Delta-gamma phase-amplitude coupling as a biomarker of postictal generalized EEG suppression. Brain Commun. 2020; 2(2): fcaa182.