Good afternoon. My name is Albert Allen. I am a second year medical student from the University of Arizona College of Medicine, Tucson. I would like to start off by saying how thankful, honored, and humbled I am for being selected to give an oral presentation at the annual AANS conference. I would also like to thank my mentor, Dr. Martin Winan and the Neurosurgery Research and Education Foundation for awarding me the 2019 Medical Student Summer Research Fellowship. Without them, this research would not have been possible. Thank you. Approximately 1% of the US population suffers from epilepsy. 30% of these patients are medically intractable and potential candidates for epilepsy surgery, most commonly amygdalo-hippocamptomy, A-H, with or without anterior temporal lobectomy, ATL, and temporal lobe epilepsy, TLE. I will be referring to these as A-H, ATL, and TLE from now on. Unfortunately, even with surgical treatment, 35% of patients still remain with persistent seizures. Thus, there is much need to develop and improve prognostic value of selection criteria in order to decrease the percentage of patients that have persistent seizures after A-H. Identification of sequence RNA biomarkers will establish gene expression profiles in patients with different seizure outcomes. Furthermore, sequence RNA biomarkers will help elucidate the pathophysiology of the neuroinflammatory response of temporal lobe epilepsy. We performed whole transcriptome sequencing to test the hypothesis that hippocampal tissue RNA expression differs between patients rendered seizure-free, SF, and non-seizure-free, NSF. To establish predictive prognostic biomarkers based on gene sets and biological pathways, following ATL and A-H. We had a total of 14 patients with a mean age of 33.1 years, ranging from 16 to 56 years, with 10 males and four females, with intractable TLE that have undergone A-H and ATL, with a one-year minimum follow-up dichotomized into SF and NSF. Logistic regression analysis of next-generation sequencing, NGS, hippocampal RNA expression datasets reveals sufficient statistical power in this cohort for prognostic value of hippocampal tissue RNA expression. Here we have a diagram I designed that highlights the pathophysiology of temporal lobe epilepsy, based on the neuroinflammatory response and the breakdown of the blood-brain barrier. Inside the brain, once a pathological sequence is started, neurons, microglial cells, astrocytes, endothelial cells, and T-cells release and upregulate inflammatory mediators and turn on specific pathways, such as the innate immune system, complement system, adaptive immune system, toll-like receptors, interleukin-1 beta, interleukin-6, tumor necrosis factor alpha, prostaglandins, platelet activating factor, cyclooxygenase, phospholipase A2, chemokines, and matrix metalloprotease. These inflammatory mediators decrease GABA-mediated neurotransmission, plus increased release of glutamate, added to an increased extracellular potassium concentration. The increase in extracellular potassium concentration raises the nerve's potential, resulting in a higher resting membrane potential, increasing the chance of ictal firing. This all leads to neuronal hyperexcitability, as you can see in this beautiful illustration. These constant insults increase the vascular permeability and the breakdown of the blood-brain barrier. Furthermore, upregulation of adhesion molecules, such as P and E-selectins and VCAM-1, vascular cell adhesion molecule 1, on the luminal side of the endothelium, forming the BBB, are seen in the epileptic brain during seizures. This results in trafficking of leukocyte adhesion and transmigration across the vascular endothelium, creating leakage and infiltration of inflammatory cells into the hippocampus, which perpetuate the cycle. Likewise, the leakage of serum proteins, such as albumin, through a disrupted BBB is hypothesized to bind to astrocytic receptors, which impair buffering of ions and neurotransmitters at the cellular level. All of these components perpetuate this neuroinflammatory insult, which may lead to neuronal cell death. I would like to take a moment to focus on this particular pathway that contributes to the pathogenesis of the blood-brain barrier, NTLE. Activation of matrix metalloprotease degrades the extracellular matrix, disrupting the blood-brain barrier, increasing leukocyte communication and increased neuronal hyperexcitability. As you see in the figure, this pathological sequence can go in multiple directions, ultimately leading to a perpetuation of epileptogenesis and increased seizure onset. We have found that there are upregulated hippocampal RNA gene expression profiles and seizure-free outcomes compared to the non-seizure-free cohort in these sets of patients. To be clear, patients that express these hippocampal RNA gene expression values and biological pathways result in seizure freedom, a desirable effect that we hope to achieve as a positive indicator for improved prognostic and selection for AH surgical candidates with medical intractable epilepsy. The first biomarker, UGT2B17, is a protein-coding gene that is involved in the glucuramidation and phase II conjugation of steroids. Neurosteroids derived from cytochrome P450 may be neuroprotective against neurodegeneration, ischemia, and epilepsy and hippocampal structures. Likewise, increased P450 expression is associated with longer status epileptic latent periods, while inhibited biosynthesis of neurosteroids produce more rapid seizure onset. Neurosteroids that have been suggested to modulate the expression of GABA-A and NMDA receptors, which may play a role in regulating antiepileptogenesis, elevations in hippocampal UGT2B17 expression may be associated with a decrease in neurosteroids perpetuating seizure onset. Increased expression might modulate hippocampal neuroinflammation and perpetuate TLE pathophysiology. Likewise, increased testosterone glucuramidation affects seizure activity by decreasing the conversion to neurosteroids in the brain. We have already discussed the pathological sequence that matrix metalloprotease has on the neuroinflammatory response on the blood-brain barrier. As you see, we had an upregulation in MMP8 and MMP13. Furthermore, KCNU1 encodes a voltage-gated ion channel, which allows the outward flow of potassium ions in the plasma membrane, resulting in the hyperpolarization in sperm. In my animated diagram, we saw how an increase in extracellular potassium concentration raises the NERDS potential, resulting in a higher resting membrane potential, increasing the chance of ictal firing and neuronal hyperexcitability. Lastly, SPAM1 expressed in our resected hippocampal tissue is a multifunctional protein that enables sperm to penetrate oocytes. Upregulation of SPAM1 is involved in microglial activation during the neuroinflammation and degradation of the extracellular matrix contributing to the pathological sequence seen in the neuroinflammatory response on the blood-brain barrier. To be clear, in this figure, patients that express these hippocampal RNA gene expression values and biological pathways result in non-seizure freedom, which is not a desirable effect as these patients that express these gene sets had persistent seizures. Thus, patients that express these biomarkers will guide selection of temporal lobe epilepsy surgical candidates. As you can see, this table is very complex. However, to break it down to its simple take-home message, these hippocampal RNA gene expression values and biological pathways are involved in the innate immune system, adaptive immune system, aminoglycolin-heavy kappa protein-coding genes, phospholipase A2, and many other inflammatory pathways listed. These pathways cause systemic inflammation where surgical treatment may leave residual inflammatory molecules leading to patients to have persistent seizures. Elucidating the pathological sequence and the bombardment of decreased GABA-mediated neurotransmission, increased release of glutamate, and increased neuronal hyperexcitability leading to vascular permeability and the breakdown of the blood-brain barrier and possible neuronal cell death. Thus, I predict that more targetable therapies will be seen, making it of fundamental importance that the future of neurosurgery be well-versed and comfortable with the growing demand of personalized therapy in a new era of neurosurgical genomics. And let me please add how honored and humbled that I have the privilege to be a part of this discovery. All in all, the exploration of the cellular and molecular mechanisms associated with neuroinflammation are of crucial importance in understanding the pathocellular physiology of TLE. In the era of President Obama's precision health initiatives, I speculate that genetic testing will personalize medicine heading our approach into the era of neurosurgical genomics, thus enhancing selection of temporal lobe epilepsy surgical candidates by establishing a predictive prognostic biomarkers for successful outcomes, as every patient deserves state-of-the-art world-class care. I would like to take a moment to thank a couple of individuals that have made a difference in my life. While spending three years on the streets as a homeless teenager in America, Dr. Martin Winan and Shana Winan have paved my path to turn my dreams to becoming an academic neurosurgeon into something I can grasp. They have become the family I always longed for in those hard times of homelessness. By putting God first in everything I do, he has protected, directed, and opened doors to a life filled with an opportunity to serve my community through the practice of medicine. As I think over all the awards and achievements, like being named 2019's 40 Under 40 Most Influential in my city and state, fills me with joy because I am remembering that boy who used to sleep under makeshift shelters navigating the fragility between life and death as a homeless teen in America. The shame that I felt back then has definitely been replaced with joy, but this joy is tempered by a sense of responsibility. I decided to become a doctor not only to pour my passion and tenacity for life into something bigger than myself, but also because I genuinely want to help people both in and outside the hospital. As I reflect and humbly try to model myself after my mentor's footsteps, I remember in the words of our founder that a physician is obligated to consider more than a diseased organ, more even than the whole man. He must view the man in his world. A world where warmth, sympathy, and understanding may outweigh the surgeon's knife or the chemist's drug. These are all the mentors and neurosurgeons from all around the world that have helped me on my path towards my dreams. Thank you to the Cleveland Clinic for allowing me to learn from world-class leaders and taking the mission that every patient deserves world-class care. Many of these individuals train me as a first-year medical student during the 2019 International Neurosurgery Resident Course in Hershey, Pennsylvania. From the US, Europe, India, and Japan, the field of medicine and neurosurgery has opened their heart to me, turning a little boy's seemingly wayward dream into this man's winning reality. I have heroes as mentors. Very blessed. During the 2019 International Neurosurgery Resident Course in Hershey, Pennsylvania, Dr. Haidt presented some words of encouragement. Having lacked a normal mainstream childhood life, once presented with these gems, I have integrated them in my daily life, and I'm compelled to share them with you. Having a hungry mind. Being resistant to fatigue. We are not the ones with the tumors. It is important to always remember why you wanted to be a brain surgeon in the first place. To always have unflagging optimism. To fight to the end for your patient, like it was your loved one on that surgical table. No matter what, always maintain your integrity to the highest degree and to do the right thing as if we lose the trust in our patients, we will not get it back. Be an active thinker, not a passive recipient, in order to search for a better way. To all the people out there that are poor and destitute, there is a place for you in this world. We live in a generous America where you don't have to be rich to achieve your highest potential. There was a time where I was without healthcare insurance and lacked proper nutrition. How on earth could I have had the possibility of even becoming a doctor if I could not even afford to be seen by one? How did I get this far in my life? Because I let my passion build into my work and synchrony for that one special day where I am in the operating room serving my future patients, in the operating room serving my future patients, being connected with them for life. I knowingly stand here in humility to share that my story has become part of the larger American story. Being selected with these fine outstanding presenters, I find myself humbled that our ideologies in the American dream are forever young and our timeless mission to preserve the blessings of our land of opportunity, where a formerly homeless teenager can achieve the humble ranks of becoming a brain surgeon in this great nation. I would like to take a quick moment to point out a paper that guides me whenever the going gets tough. These are very inspiring words from Dr. Robert Harbaugh. Please read this article in red text called the 2015 AANS Presidential Address, Neurosurgery's Founding Principles. Thank you.

Albert Allen

medical student

AANS conference

epilepsy

RNA biomarkers