CURE Epilepsy Discovery: Funding Basic Mechanisms Research Drives Momentum Toward a CURE

Key Points:

• For 25 years, CURE Epilepsy has been funding breakthrough research to advance science to find a cure for epilepsy. A key focus of our research grants has been understanding the basic biological mechanisms that result in epilepsy, which provides foundational knowledge that will ultimately lead to a cure for epilepsy.
• One initiative funded by CURE Epilepsy, the Infantile Spasms (IS) Initiative, brought together a diverse team of medical and scientific experts to rapidly advance IS research and was the first initiative of its kind in the field of epilepsy.
• John Swann of Baylor College of Medicine, whose work is discussed herein, was one of the grantees involved in the IS Initiative. He has progressed his initial discoveries, demonstrating the importance of funding basic mechanisms research to put us one step closer to a cure.
• Basic research provides hope for a cure for the epilepsies; by better understanding the mechanisms that cause seizures, we can develop curative treatments for the epilepsies.

Deep dive

Twenty-five years ago, CURE Epilepsy was founded finding a cure for epilepsy and related seizure disorders, which now impacts 3.4 million Americans and 65 million people worldwide. The founders saw a need to push the research community to think differently about epilepsy research. This resulted in a paradigm shift for the community, moving from seeking treatments and therapies that would control seizures to focusing on innovative approaches that would advance science and find a cure for epilepsy. Achieving this goal would provide freedom from seizures and the negative side effects of medications. The organization determined that it could have the largest impact by focusing on understanding the basic biological mechanisms underlying the causes of epilepsy. Understanding is the first step in the scientific process, where researchers study the brain to gain a better understanding of why and how seizures are caused. These findings create foundational knowledge that may translate to new ideas to treat epilepsy and eventually preclinical and clinical trials. Clinical trials may ultimately lead to improved and potential cures. Hence, while the benefits of basic epilepsy research are not immediate, the rewards that basic research provides in terms of our understanding epilepsy are unparalleled.

Since 1998, CURE Epilepsy has funded over 280 research grants, and many have addressed the need to learn more about the basic biological mechanisms that underlie epilepsy. Many of these grants have formed the basis for further study, learning, and advancements that may lead us to a cure. One example of this is within infantile spasms (IS), a rare and particularly severe form of epilepsy, with approximately 90% of cases diagnosed in the first year of life. Infantile spasms manifest as sudden, jerking movements of the arms and legs, and are often accompanied by an irregular brainwave pattern on the electroencephalogram (EEG) called hypsarrhythmia.[1]These seizures are also often accompanied by significant cognitive and physical deterioration.[2] Current therapies for IS are effective in only half of the children with IS [3] and are associated with negative side effects, highlighting the need to find better and more effective treatments.

In 2013, CURE Epilepsy launched the Infantile Spasms Initiative, with $4 million in funding. The IS Initiative employed a multi-disciplinary and multi-location team science approach to study the basic biological mechanisms underlying IS, search for biomarkers and novel drug targets, and develop improved treatments. Work done as part of the IS Initiative proved successful across multiple dimensions and led to more than 19 publications. More about the IS Initiative can be found here.[4]

Understanding the basic biological mechanisms underlying IS was a key focus of the IS Initiative. One example of the IS Initiative’s success in understanding a key underlying basic mechanism is from the team led by Dr. John Swann of Baylor College of Medicine.[1] Dr. Swann and his team discovered that treatment with a derivative of the growth hormone insulin-like growth factor 1 (IGF-1) called (1-3) IGF-1 reduced spasms and irregular brain wave patterns on the EEG in an animal model. Adding this compound to vigabatrin, an FDA-approved treatment for IS, reduced the dose of vigabatrin required to eliminate the spasms. Reducing the dosage also decreased the risk of serious side effects, including the potential for irreversible peripheral vision loss. The Swann lab patented this combination treatment and used the discovery to obtain two National Institutes of Health (NIH) grants. The NIH grants enabled Dr. Swann to build on the discoveries from the CURE Epilepsy-funded IS Initiative. In a subsequent study, data from Dr. Swann’s team revealed that the levels IGF-1 itself were lower in brain tissue from both a rat model and from infants with IS. Data also indicated that reduced expression of IGF-1 in the rat model affected the biological pathways critical for neurodevelopmental processes.[6]

Using the learnings from the IS Initiative as a foundation, through a series of additional experiments, the team confirmed that the (1-3) IGF-1 could also cross the blood-brain barrier with much higher efficiency than the full-length IGF-1 and activate the same biological pathways as full-length IGF-1.[7] The researchers administered it to the rats in their experiment, and successfully eliminated both the spasms and the hypsarrhythmia in most rodents. This exciting finding suggests that this smaller (1-3) IGF-1 or perhaps an IGF-1-like drug may one day be used to treat IS patients immediately after the condition is diagnosed. You can read more about this study here.

Dr. Swann and his team have continued to build on the learnings initially funded through their CURE Epilepsy grant; recently, the team studied seizure progression in IS, and the impact of spasms on learning and memory.[8] Infants with IS show developmental delay and behavioral abnormalities, with only 16% of patients with IS exhibiting normal intellectual development.[9] The reasons for a delay in intellectual development could be many, though they have not yet been determined.[10,11] Additionally, the trajectory of the decline in intellectual and behavioral abilities has not yet been documented due to the variability of the condition, and limitations in assessing intellectual abilities in infants. Spasms can be subtle, making an accurate diagnosis of the exact start of the spasms challenging.[12] Hence, whether the behavioral decline is caused by or simply associated in time with seizures in IS is an area where more research is necessary. Given the difficulties of understanding this relationship between seizures and cognitive decline in infants with IS, Dr. Swann’s team used rats with a history of spasms and assessed them in a series of tests to gauge their ability to learn and remember. Swann’s team used rats with a history of spasms and assessed them in a series of memory tests to gauge their ability to learn and remember. The team also studied their brainwaves using EEG.

Previous work by Dr. Swann’s team had developed a model to simulate IS in animal models.[13] In this model, a substance known as tetrodotoxin (TTX) is infused into the brains of infant rats 10-12 days after birth which causes many of the characteristics of IS, including spasms, seen in humans.[13] The research team then used tests to examine spatial and working memory. Spatial memory helps us remember locations and the relationship between locations, and working memory helps us remember a small part of the information in our minds temporarily. To better understand the brainwaves in rats that had spasms, Dr. Swann’s team performed continuous EEG recordings for a total of seven weeks after infusion of TTX.[8] Rats with spasms were compared with rats that did not have spasms. After seven weeks of EEG recording, behavioral tests were done to test learning and memory. The study showed that rats experiencing spasms showed impairment on the behavioral tests, pointing to issues in learning and memory, which are also seen in infants with IS.[8] EEG analysis showed that there was an increase in spasms for two weeks, and after the two weeks, spasms stabilized.[8] Seizure progression in epilepsy has long been a topic of intense research. The current study suggests that like other seizure disorders[14,15], there may be a critical period in IS when there is a gradual increase in spasm intensity over time. A better understanding of seizure progression patterns in IS could lead to clues about therapies, management, and prognosis. This work from Dr. Swann’s lab is unique as the team did rigorous EEG monitoring and behavioral analysis; these techniques are time and labor-intensive, and seizures in IS have not been studied this deeply before.[8] The neurological mechanisms that underlie memory disturbances and seizure progression in IS are not fully known. So, seizures could be correlated with the learning deficits, but exact details are not clear. Additional research using EEG monitoring coupled with behavioral analysis in the same animals could provide clarity into the relationship.

In conclusion, basic research provides a foundational understanding of underlying biology of a disease process from which cures for the epilepsies will be found. CURE Epilepsy has been funding basic research for 25 years with the sole mission of finding a cure for epilepsy. Dr. Swann’s work as part of the IS Initiative is one example of how strategic, long-term investment in basic research can advance our knowledge by leaps and bounds.

Literature Cited:

1. Gibbs EL, Fleming MM, Gibbs FA. Diagnosis and prognosis of hypsarhythmia and infantile spasms Pediatrics. 1954 Jan;13:66-73.
2. Cowan LD, Hudson LS. The epidemiology and natural history of infantile spasms J Child Neurol. 1991 Oct;6:355-364.
3. Knupp KG, Coryell J, Nickels KC, Ryan N, Leister E, Loddenkemper T, et al. Response to treatment in a prospective national infantile spasms cohort Ann Neurol. 2016 Mar;79:475-484.
4. Lubbers L, Iyengar SS. A team science approach to discover novel targets for infantile spasms (IS). Epilepsia Open. 2021;6:49-61.
5. Swann J, Lee, CL., Le, JT. and Frost Jr, JD. , inventor; Combination therapies for treating infantile spasms and other treatment resistant epilepsies 2022.
6. Ballester-Rosado CJ, Le JT, Lam TT, Mohila CA, Lam S, Anderson AE, et al. A Role for Insulin-like Growth Factor 1 in the Generation of Epileptic Spasms in a murine model Ann Neurol. 2022 Jul;92:45-60.
7. Yamamoto H, Murphy LJ. Enzymatic conversion of IGF-I to des(1-3)IGF-I in rat serum and tissues: a further potential site of growth hormone regulation of IGF-I action J Endocrinol. 1995 Jul;146:141-148.
8. Le JT, Ballester-Rosado CJ, Frost JD, Jr., Swann JW. Neurobehavioral deficits and a progressive ictogenesis in the tetrodotoxin model of epileptic spasms Epilepsia. 2022 Dec;63:3078-3089.
9. Hrachovy RA, Frost JD, Jr. Infantile epileptic encephalopathy with hypsarrhythmia (infantile spasms/West syndrome) J Clin Neurophysiol. 2003 Nov-Dec;20:408-425.
10. Wirrell EC, Shellhaas RA, Joshi C, Keator C, Kumar S, Mitchell WG. How should children with West syndrome be efficiently and accurately investigated? Results from the National Infantile Spasms Consortium Epilepsia. 2015 Apr;56:617-625.
11. Osborne JP, Lux AL, Edwards SW, Hancock E, Johnson AL, Kennedy CR, et al. The underlying etiology of infantile spasms (West syndrome): information from the United Kingdom Infantile Spasms Study (UKISS) on contemporary causes and their classification Epilepsia. 2010 Oct;51:2168-2174.
12. Lux AL, Osborne JP. A proposal for case definitions and outcome measures in studies of infantile spasms and West syndrome: consensus statement of the West Delphi group Epilepsia. 2004 Nov;45:1416-1428.
13. Lee CL, Frost JD, Jr., Swann JW, Hrachovy RA. A new animal model of infantile spasms with unprovoked persistent seizures Epilepsia. 2008 Feb;49:298-307.
14. Jeavons PM, Bower BD. The natural history of infantile spasms Arch Dis Child. 1961 Feb;36:17-22.
15. Golomb MR, Garg BP, Williams LS. Outcomes of children with infantile spasms after perinatal stroke Pediatr Neurol. 2006 Apr;34:291-295.