PACIFIC NEUROSCIENCE INSTITUTE - Key Persons
Job Titles:
- Scientific Writer - Neurosurgery
Job Titles:
- Clinical Research Associate TRIP
- Clinical Research Coordinator for the Pacific Treatment & Research in Psychedelics
- Treatment & Research in Psychedelics
Ashley Ramos is a Clinical Research Coordinator for the Pacific Treatment & Research In Psychedelics (TRIP) Center at Pacific Neuroscience Institute. She facilitates patient recruitment, organizes and oversees participant activities including visits with multiple providers, handles participant progression through the trial, and is involved in data entry/analysis as well as in manuscript writing. Alongside her work in psychedelic research, she also provides support to other research areas within Pacific Neuroscience Institute.
Ashley received her Bachelor of Science in Animal Biology at the University of California, Davis where she worked in the Behavioral Neuroendocrinology Lab assisting with research on mood and anxiety disorders.
Job Titles:
- Member of the PNI Foundation Team
- Chief Administrative Officer Chief Operating Officer PNI Foundation
Job Titles:
- Director, Otology / Neurotology - Lateral Skull Base Surgery Director, Adult & Pediatric Cochlear Implant Program
- Ear
Courtney Voelker, MD, PhD (DPhil Oxon), is a Rhodes Scholar and board certified neurotologist. She is Director of Otology/Neurotology-Lateral Skull Base Surgery; and Director of the Adult & Pediatric Cochlear Implant Program at Pacific Neuroscience Institute. She is an otolaryngology - head & neck surgeon who takes care of adult and pediatric patients seeing a wide range of inner ear and skull base conditions. Dr. Voelker developed PNI's enhanced treatment protocol for the treatment of acoustic neuromas. For qualified patients who suffer hearing loss before or after surgery, a cochlear implant may be placed in the affected ear to restore hearing at the time of tumor removal-a unique feature offered at few institutions. Dr. Voelker is a member of the Acoustic Neuroma Association Medical Advisory Board. A Super Doctor Rising Star award recipient, she is committed to offering top quality, compassionate care to all her patients.
Prior to joining PNI, Dr. Voelker was at USC Caruso Department of Otolaryngology - Head and Neck Surgery, Keck School of Medicine of USC as Division Chief of Otology, Neurotology and Lateral Skull Base Surgery, and the Director of the Pediatric Cochlear Implant program at Children's Hospital Los Angeles (CHLA). She has conducted leading-edge research on the physiology and diseases of the inner ear at Brown University, the University of Oxford, Washington University in St. Louis, and the National Institutes of Health (NIH).
Dr. Voelker has authored numerous research publications and textbook chapters in her field. She is a member of the American Academy of Otolaryngology - Head and Neck Surgery and the American Neurotologic Society. She is member of the Acoustic Neuroma Association Medical Advisory Board.
Dr. Voelker graduated with Honors from Brown University and earned her medical degree from The Warren Alpert Medical School of Brown University. As a Rhodes Scholar she earned her PhD from the University of Oxford in developmental neurobiology. She completed her residency in Otolaryngology - Head and Neck Surgery at the Washington University (Barnes-Jewish Hospital) in St. Louis and her fellowship at the world-renowned House Ear Clinic in Los Angeles.
Throughout her career, Dr. Voelker has made it part of her practice to do mission-based humanitarian work in developing countries. In partnership with Global ENT Outreach, she has treated underserved populations where ear disease can go unchecked for years. In addition, she has conducted numerous temporal bone courses to train doctors in emerging economies where specialty physician resources and training are sparse.
Job Titles:
- Psychiatrist
- Director, Brain Health Center Geriatric Psychiatry
- Geriatric Psychiatry
David A. Merrill, MD, PhD, is a double-board certified adult and geriatric psychiatrist and neuroscientist. He is director of the Pacific Brain Health Center (PBHC) at the Pacific Neuroscience Institute. His practice, educational, and research activity focus on the Precision Brain Health Program (PBHP), applying precision medicine approaches to optimize brain aging in middle-aged and older adults at risk for and with neurodegenerative disorders including Alzheimer's disease (AD) and Parkinson's (PD). He also directs the transcranial magnetic stimulation (TMS) consult service at PBHC for depression and cognition.
Dr. Merrill graduated Phi Beta Kappa from the University of California, Berkeley, completing a double major with Highest Honors in Psychology and High Honors in Molecular and Cellular Biology. He then completed the National Institutes of Health (NIH) funded Medical Scientist Training Program at the University of California, San Diego. He earned his PhD in Neurosciences at UCSD studying brain-derived neurotrophic factor (BDNF) amelioration of age-related cognitive deficits. His graduate studies led to the publication of a seminal work in the field of plasticity and aging in the journal Nature Medicine.
He completed his Adult Psychiatry Residency at the University of California, Los Angeles, School of Medicine which included a final year as program Chief Resident. He then completed a two-year combined clinical and research Geriatric Psychiatry Fellowship at UCLA before joining the faculty. During his 8-years on the full-time UCLA Psychiatry Faculty, Dr. Merrill fulfilled teaching, service, and research roles.
At UCLA, he was nominated multiple times for the annual Resident Teaching Award of Psychiatry trainees for his work supervising in both hospital and clinic-based settings. He was awarded competitive career development awards from both the UCLA Older Adults Independence Center and then the UCLA Center for Translational Science Institute. His work at UCLA examining the brain effects of health lifestyle behaviors (including diet, exercise, and stress reduction) resulted in multiple high-impact publications and wide social media coverage. Dr. Merrill continues to collaborate across institutions as an active member of the UCLA Psychiatry Volunteer Clinical Faculty.
In collaboration with the PNI Founders, Dr. Merrill and his colleagues opened the Pacific Brain Health Center in 2018. Since then, he and PBHC's multi-disciplinary team have worked continually with patients and families facing age-related neurodegenerative disorders such as AD and PD while carrying out educational and research projects in this area. Through his ongoing study and early adoption of emerging clinical practices and technologies, Dr. Merrill has developed a "precision holistics" approach that combines personalized biomarker data with the best evidenced-based treatments available for alleviating mood disorders and cognitive dysfunction within the context of aging.
Research Interests
Precision Medicine
Aging and Memory
Mood Disorders
Fitness and Cognition
Alzheimer's and Related Dementias
Keeping Dementia at Bay, Every Day | A PNI Panel Discussion Dr. David Merrill is a psychiatrist who specializes in older adults. He has a PhD in the neurobiology of aging, and he directs PNI's Brain Health Center. His colleague Dr.
Job Titles:
- Research Assistant
- Research
DeLisa Madere is a Clinical Research Associate for the Department of Translational Neurosciences. She assists in coordinating clinical trials for the Neurological Oncology Department at Saint John's Cancer Institute. She helps with patient recruitment, consenting, coordinating clinical visits, including different tests and procedures, and keeping up with data entry for both pharmaceutical studies and investigator-initiated studies designed by the Neuro-Oncology doctors.
DeLisa graduated from Loyola Marymount University with a Bachelor of Science in Biology. She joined the Saint John's Cancer Institute in July 2020 where she previously started out as a Research Assistant, helping with non-therapeutic clinical trials and biospecimen collections.
Job Titles:
- Member of the Clinical Trials Team
- Associate Professor of Neurology at the Saint John 's Cancer Institute
- Board - Certified Neurologist
Jose Carrillo, MD, is a board-certified neurologist and neuro-oncologist specializing in the diagnosis and treatment of primary and secondary brain tumors, including glioblastoma multiforme, primary CNS lymphoma, meningioma, and brain metastases, as well as the neurologic complications of cancer. In addition, Dr. Carrillo is involved in the enrollment of patients into several clinical trials.
Dedicated to advancing medicine, Dr. Carrillo is a strong proponent of leading-edge research in the diagnosis, treatment and prevention of all types of CNS tumors, including metastatic brain and spine tumors, primary malignant brain and spinal cord tumors, primary benign or low-grade brain or spine tumors, and skull base and pituitary tumors. His particular research interests involve neuroimaging brain tumor features and molecular markers pertaining to treatment and survival.
Dr. Carrillo is an Associate Professor of Neurology at the Saint John's Cancer Institute at Providence Saint John's Health Center and has been recognized by Coast magazine as a Physician of Excellence, and by L.A. Magazine as a Southern California Super Doctor.
If there is a textbook definition of what a "model doctor" should be like, it is Dr. Carrillo. He is as caring and personable as he is a world class expert in his field. He is SO patient in explaining and going over reports and his recommendations with you. He seems always eager to see you doing well and is always on top of prescriptions and lab orders. My mother (his patient) was sad when he transferred. His new hospital and patients are blessed to have him!
Job Titles:
- Director, Pacific Movement Disorders Center Neurology
- Neurology
Dr. Melita Petrossian is a fellowship-trained neurologist and movement disorders specialist and is the Director of the Pacific Movement Disorders Center located at Providence Saint John's Health Center and Providence Little Company of Mary Medical Center Torrance.
Dr. Petrossian's clinical interests and expertise are in movement disorders such as Parkinson's disease (PD), tremor including essential tremor, dystonia, gait disorders, ataxia, myoclonus, blepharospasm, hemifacial spasm, Meige syndrome, spasticity, tics and Tourette's syndrome. She also specializes in Parkinson's-related conditions such as Dementia with Lewy Bodies, progressive supranuclear palsy, multiple system atrophy, corticobasal degeneration, primary freezing of gait, and Parkinson's Disease Dementia.
Dr. Petrossian's focus is on a multidisciplinary approach to these movement disorders, including appropriate diagnosis utilizing the latest imaging techniques such as MRI, PET and DaTscan, optimization of medical treatment, and chemodenervation using botulinum toxin injections (e.g., Botox). In coordination with physical therapists, occupational therapists, speech therapists, and other specialists as necessary she treats motor and non-motor symptoms of PD and other movement disorders. Dr. Petrossian provides assessments for candidates for deep brain stimulation surgery for PD, essential tremor and dystonia, guides patients through the pre- and post-operative period, and creates a custom-tailored program of deep brain stimulation settings.
A native of southern California, Dr. Petrossian graduated from UCLA, summa cum laude, and received her medical education at the University of California, San Francisco (UCSF). She completed her neurology residency at Massachusetts General Hospital and Brigham and Women's Hospital, affiliated with Harvard Medical School in Boston, followed by fellowship in movement disorders at the same institutions. She is a member of the American Academy of Neurology (AAN) and Movement Disorders Society (MDS).
Job Titles:
- Board - Certified Neurologist
- Neurology
- Specialist
Dr. Natalie Diaz is a board-certified neurologist with fellowship training in movement disorders. Her clinical practice focuses on the evaluation and management of patients with Parkinson's disease, atypical parkinsonian disorders, Huntington's disease and other choreiform disorders, dystonia, and ataxia.
She also has specialized training in the evaluation and programming of deep brain stimulation as a treatment for Parkinson's disease, essential tremor and dystonia as well as the therapeutic administration of botulinum toxin injections for non-cosmetic indications such as focal dystonia, hemifacial spasm and limb spasticity. Her research focuses on industry-sponsored clinical trials in Parkinson's disease and other collaborative clinical projects in the field of neurodegenerative disorders.
Dr. Natalie Diaz is a movement disorders specialist. In this PNI Minute, she reviews the importance of sleep in a two part series. Today I want to talk about sleep and how important sleep is for proper brain function, to reduce aging, and also for…
Dr. Natalie Diaz is a movement disorders specialist. In this PNI Minute, she talks about sleep and diseases like Parkinson's disease.
Job Titles:
- Physician
- Scientist
- Neuro - Oncology
Santosh Kesari, MD, PhD, FANA, FAAN, is one of "America's Top Doctors" selected by Castle Connolly Medical Ltd. He is among the top 1% of neuro-oncologists and neurologists in the nation, according to Castle Connolly Medical Ltd. Each year, Castle Connolly surveys thousands of physicians and other healthcare professionals and asks them to identify excellent doctors in every specialty in their region and throughout the nation for their Top Doctors™ distinction.
Dr. Kesari is often called upon by the media to comment on neurological issues and the non-surgical treatment of brain tumors.
Man On A Mission Dr. Santosh Kesari is on a mission to put an end to deadly brain cancers.
Job Titles:
- Clinical Trials Nurse Supervisor
- Research
Emma Chacon is part of the neuro-oncology research team and is a Clinical Trials Nurse Supervisor.
Job Titles:
- Clinical Trials & Research
- Head & Neck
Job Titles:
- Member of the Clinical Trials Team
- Neurosurgery
Garni Barkhoudarian, MD, FAANS, is a board-certified, fellowship-trained neurosurgeon with a focus on skull base and minimally invasive endoscopic surgery. Dr. Barkhoudarian has particular interest and expertise in pituitary and parasellar tumors, brain tumors, skull-base tumors (including meningiomas, craniopharyngiomas, chordomas and schwannomas), intra-ventricular brain tumors, colloid cysts, trigeminal neuralgia, hemifacial spasm and other vascular compression syndromes.
Job Titles:
- Certified Nurse Practitioner
- Neurosurgery
- Nurse Practitioner, Movement Disorders Center
Giselle is a certified nurse practitioner with extensive clinical experience. She brings her competent and compassionate care of patients to the Pacific Movement Disorders Center at Pacific Neuroscience Institute.
Giselle graduated with her Bachelor of Science in Nursing from the Remedios Trinidad Romualdez Memorial School-Makati Medical Center, Philippines. She worked in the Intensive Care Unit, and soon proceeded to become the Rapid Response Nurse at Providence Saint John's Health Center. A dedicated caregiver, Giselle continued her training in a Master's program at the Charles R. Drew University of Medicine and Science Mervyn M. Dymally School of Nursing in Los Angeles, where she was awarded the Namahyoke Sockum Curtis Excellence in Academic Achievement award and graduated from the Family Nurse Practitioner Program as a Certified Nurse Practitioner.
Giselle initiated and continues to run the Life In Motion Parkinson's support group for PD patients and their families. She helps moderate and lectures at the PRESS program, which is the Parkinson's Roadmap for Education and Support Services, a program for newly diagnosed PD patients, in collaboration with the American Parkinson Disease Association (APDA).
Job Titles:
- Board - Certified Neurologist
- Director of the Stroke and Neurovascular Center
- Director, Stroke & Neurovascular Center Vascular and Interventional Neurology
- Neurointerventional Surgery
Jason W. Tarpley, MD, PhD is a board-certified neurologist with fellowship training in vascular and interventional neurology. He specializes in the clinical care of patients with neurovascular disorders and has specific interest in ischemic and hemorrhagic stroke, cerebral aneurysms, and carotid artery stenosis.
He is an investigator in many phase 2 and phase 3 clinical studies examining the safety and effectiveness of innovative therapies in stroke patients. He has published many papers and presented his research at domestic and international conferences. Dr. Tarpley serves as the Stroke Medical Director for Pacific Stroke and Neurovascular Center. He is also the clinical lead for Providence's system-wide Clinical Stroke Research.
Jason Tarpley, MD, PhD, Director of the Stroke and Neurovascular Center at Pacific Neuroscience Institute (PNI) explains how to identify and treat stroke, and reviews lifestyle changes you can make today to lower your risk of stroke today.
Job Titles:
- Clinical Research Associate
- Research
Jazmin is a clinical research associate with the neuro-oncology team, at Pacific Brain Health Center.
Job Titles:
- Director, Restorative Neurosurgery and Deep Brain Stimulation Program Director Neuro - Spine Surgery, Spine Institute, PNI - South Bay Neurosurgery
- Neurosurgery
Jean-Philippe Langevin, MD, is a board-certified and fellowship-trained neurosurgeon specializing in the surgical treatment of movement disorders, epilepsy and psychiatric conditions.
He was selected as a 2016 Superdoctors Rising Star and achieved the Superdoctor designation again in 2017. He has extensive experience using neuromodulation to treat conditions such as Parkinson's disease, essential tremor, dystonia, epilepsy and obsessive-compulsive disorder (OCD).
He employs a variety of treatment modalities including deep brain stimulation (DBS), vagal nerve stimulation (VNS) and interstitial laser ablation. He is Director of the Restorative Neurosurgery and Deep Brain Stimulation Program at the Pacific Movement Disorders Center located at Providence Saint John's Health Center and Providence Little Company of Mary Medical Center Torrance.
As the Director of Neuro-Spine Surgery at the Spine Institute at Little Company of Mary, Dr. Langevin sees patients with a wide array of spine disorders. Working with a team of multi-disciplinary colleagues, he treats back issues caused by tumors, back pain, or other trauma.
Career Highlights
Dr. Langevin's research interests include the application of neuromodulation to treat neuropsychiatric illnesses. He is the principal investigator of a trial evaluating non-invasive trigeminal nerve stimulation as a potential treatment modality for chronic post-concussive syndrome.
He is also the principal investigator for the clinical trial using DBS to treat post-traumatic stress disorder (PTSD) in combat veterans. This effort was recently reported in Popular Science. As part of this trial, Dr. Langevin performed the first ever surgery to address the symptoms of PTSD. He is also currently studying the potential application of DBS in substance use disorder.
Dr. Langevin obtained his medical degree from McGill University in Canada. He then completed his residency in neurosurgery and his fellowship in functional neurosurgery (i.e. DBS surgery) at the University of California, Los Angeles (UCLA). Following his graduation, he led the surgical DBS program at the University of Arizona Medical Center and the affiliated Southern Arizona VA Healthcare.
In 2012, he was recruited to lead the surgical DBS program and the epilepsy surgery program at the Greater Los Angeles VA which serves as the US Southwest referral center. In this role, he has applied the use of a novel frameless technology in the treatment of movement disorder and epilepsy to improve patient comfort and facilitate smoother recovery after surgery.
Dr. Langevin obtained his certification from the American Board of Neurological Surgeons and is a member of the American Association of Neurological Surgeons, the Congress of Neurological Surgeons and the American Society for Stereotactic and Functional Neurosurgery. He brings several years of experience in treating neurological and psychiatric disorders using neuromodulation and DBS.
Job Titles:
- Member of the Clinical Trials Team
- Research
- Senior Research Scientist at the Pacific Neuroscience Institute Foundation
- Senior Research Scientist, Brain Health Center
Jennifer Bramen, PhD, is a neuroscientist with expertise in neuroscience research, advanced neuroimaging, and non-pharmacological interventions for cognitive decline. She obtained her PhD in Neuroscience from the University of California, Los Angeles (UCLA), where she also completed her postdoctoral research fellowship at the Laboratory of Neuroimaging (LONI).
During her time as an Assistant Research Neuroscientist at the UCLA's Center for Cognitive Neuroimaging, she made significant contributions to the field. She published groundbreaking work on real-time functional magnetic resonance imaging (fMRI) technology aimed at in-scanner neurofeedback to reduce craving levels in smokers. As part of her work with the UCLA Center on Aging, she conducted research focused on the early diagnosis of Alzheimer's disease using techniques such as FDG PET and hippocampal unfolding. She was also a lecturer in the Neuroimaging Training Program.
With a passion for bridging the gap between translational research and clinical implementation, Dr. Bramen currently serves as a Senior Research Scientist at the Pacific Neuroscience Institute Foundation, which houses its memory research program within the Pacific Brain Health Center (PBHC), an outpatient dementia care clinic and center of excellence at Pacific Neuroscience Institute. (partnered with the Providence Health system). At PBHC, Dr. Bramen collaborates closely with clinician-scientists to facilitate the integration of research findings into clinical practice. She leads the Neuroimaging Core, which provides neuroimaging-based biomarkers and supports automated data abstraction from the electronic health record to facilitate a better understanding clinical outcomes and measure the efficacy of clinical trials.
Dr. Bramen's research primarily focuses on interventions for Alzheimer's disease (AD) and related dementias. She is currently engaged in developing neuroimaging-based outcome measures and non-pharmacological interventions to combat cognitive decline. She has made notable contributions to the field as an inventor of AD-NeuroScore, a novel sMRI-based metric that utilizes clinically available measures and a novel (patent pending) algorithm to assess neurodegeneration associated with AD. AD-NeuroScore is distinguished by its clinical feasibility, interpretability, and its potential to improve the patient experience. Notably, it accounts for variations in scans performed at different facilities with different scanners, ensuring the validity of longitudinal follow-up reports.
Dr. Bramen is engaged in intervention research aimed at enhancing the efficacy of multi-modal lifestyle interventions. These interventions employ a combination of coaching and precision-medicine to improve behavior change and simplify treatment approaches. She also collaborates with the Institute for Systems Biology (ISB) on systems biology research to better understand the complex interactions between environment, behavior, genetics, and physiological systems measured using metabolomics and proteomics. The goal of this work is to apply an integrative approach to enhance our understanding of individuals as integrated systems and contribute to the advancement of personalized medicine.
Job Titles:
- Treatment & Research in Psychedelics
- Treatment & Research in Psychedelics Clinic Supervisor
Job Titles:
- Member of the PNI Foundation Team
- Medical Illustrator, Lab Manager
Job Titles:
- Treatment & Research in Psychedelics
Job Titles:
- Treatment & Research in Psychedelics
Job Titles:
- Administrative Coordinator
- Administrative Coordinator for the Treatment & Research in Psychedelics
Krystal serves as the administrative coordinator for the Treatment & Research In Psychedelics (TRIP) program at Pacific Neuroscience Institute. She supports Dr. Keith Heinzerling both for ketamine therapy patients and clinical trials participants, Dr. Shanthi Gowrinathan, Director of Psycho- Oncology, and Corwin Patis and Jessica Dizon of the Brain Heath Physical Therapy Department. Krystal is responsible for appointment scheduling, obtaining health insurance authorizations, and acts as a patient/physician liaison for other patient needs and questions for all these departments.
Krystal began her career in healthcare in 2009 as the Office Manager at a private Aesthetic Medicine and Dermatology practice. Seeking the challenge of a broader healthcare network to have an impact on a wider range of patients, Krystal joined PNI and the Providence System in 2022.
Job Titles:
- Administrative Coordinator
Maya Gray is the Administrative Coordinator for the Pituitary, Brain Tumor, Adult Hydrocephalus, Facial Pain Centers & Multiple Sclerosis Clinics.
Job Titles:
- Treatment & Research in Psychedelics
Job Titles:
- Administrative Assistant, Department of Neurosciences and Neurotherapeutics
Nancy is an administrative assistant working as part of the Department of Translational Neurosciences and Neurotherapeutics clinic with Dr. Santosh Kesari and Dr. Jose A. Carrillo. She provides patient care support to neuro-oncology patients and is responsible for appointment and imaging scheduling, obtaining health insurance authorizations, and acting as a patient/physician liaison for other patient needs and questions. She provides advanced professional, confidential and administrative clinical support to the department.
Nancy works with our patients providing written and verbal instructions for any tests/imaging requiring special preparation that may be required before their appointment or follow up visit. She assists with pre-screening of medical records and imaging studies, appointment scheduling, securing authorization, and coordination of medical treatment scheduling. It is a priority of our clinical administrative assistants to help patients and their families feel informed and secure throughout their course of treatment. She is fluent in Spanish.
Providence Little Company of Mary Medical Center Torrance Providence Little Company of Mary Medical Center Torrance has been serving Torrance, the Beach Cities and Greater South Bay communities since 1960, and has earned a reputation for clinical excellence, use of advanced technology, and a distinct focus … Continue reading Providence Little Company of Mary Medical Center Torrance
Job Titles:
- Member of the PNI Foundation Team
REBECCA LEWIS, AuD Audiology Director, Adult & Pediatric Cochlear Implant Program; Audiologist Dr. Lewis is a board certified audiologist focusing on adult and pediatric patients. An avid clinician, educator, and…
Dr. Kesari's publication list regarding conditions and novel treatment approaches is extensive.
Job Titles:
- Member of the PNI Foundation Team
- Marketing & Communications