Meet Our Team

Dr. Ramya Rangamannar earned her bachelor’s degree from Barnard College at Columbia University and her master's and doctorate degrees in Clinical Psychology from the University of Hartford. She completed her pre-doctoral clinical internship at the University of Florida and post-doctoral fellowship in pediatric neuropsychology at the Children’s Hospital Colorado.

Over the last decade, Dr. Ramya has gained clinical expertise in a multitude of settings (i.e., medical, psychiatric, private practice) with children from early toddlerhood through early adulthood. Despite specialization in pediatrics, Dr. Ramya has also worked with adult and geriatric populations in her training. She prides herself on understanding the "whole child" in the context of their home/family, school, and social realms and in providing families with tangible resources and recommendations in supporting their child’s development and success.

Dr. Dorothy Nguyen-Daniels earned her doctoral degree with a concentration in neuropsychology from the Illinois School of Professional Psychology. She completed her pre-doctoral internship at Truman Memorial Veterans’ Hospital in Missouri and her two-year postdoctoral fellowship in neuropsychology at the University of Kansas School of Medicine-Wichita. In addition, she obtained a master’s degree in gerontological counseling from Adler University in Illinois.

Dr. Nguyen-Daniels provides comprehensive outpatient evaluations of adults and older adults presenting with various neurological conditions, including dementia, mild cognitive impairment, concussion/traumatic brain injury, neurodegenerative disease, stroke, cerebrovascular disease, epilepsy, movement disorders, autoimmune disorders, and complex medical/psychiatric conditions. She also has experience conducting pre-surgical evaluations (e.g., epilepsy, DBS) and inpatient consultations. In her clinical work, Dr. Nguyen-Daniels strives to use a thorough, compassionate, and culturally-sensitive approach that enables patients to understand better their strengths, areas of growth, and helpful resources to function and feel their best.

Dr. Molly Sullan earned her doctorate degree in clinical psychology, with a specialization in neuropsychology, from the University of Florida. She completed her pre-doctoral internship and her two-year neuropsychology fellowship at the VA San Diego Healthcare System/University of California, San Diego.

Dr. Sullan’s research has focused on understanding the relationship between post-traumatic sleep difficulties and cognitive, psychological, and physiological recovery for patients with a history of acquired brain injury (e.g., traumatic brain injury and stroke). Clinically, she has experience in the assessment of a broad spectrum of neurological disorders both in inpatient and outpatient settings, including brain tumors, epilepsy and movement disorders (e.g., Parkinson’s disease), memory disorders and dementia, stroke and cerebrovascular disease, traumatic brain injury, demyelinating lesions, autoimmune disorders, complex psychiatric concerns, substance use disorders, and neurodevelopmental considerations.

Dr. Sullan is an affiliate faculty member at Horizon, which means that she does not currently see patients clinically. She works in research and remains involved with the HNS didactic series related to the HNS training program.

Dr. Alexis Sliva earned her bachelor’s degree in psychology from University of Wisconsin - River Falls and her master’s and doctorate degrees in school psychology from the University of Denver. She completed her pre-doctoral internship and post-doctoral fellowship in clinical psychology at a private practice in Las Vegas, Nevada, with an emphasis on forensic psychology.

Dr. Sliva’s early training focused on supporting students and families from the school environment. Her clinical training has focused on intervention, evaluation, and assessment across community resource center and private practice settings. While she specialized in childhood to early adulthood, she also worked with adult populations. She has experience in the assessment of mood disorders, anxiety, PTSD, psychosis, ADHD, and learning disabilities. In addition, her forensic experience consisted of completing Court ordered evaluations (e.g., child custody, risk, and certification). She is passionate about working with families to establish diagnostic clarity and subsequent resources. She is excited to broaden her clinical experience by completing a lifespan residency in clinical neuropsychology at HNS.

Sabrina is a graduate of the University of Central Florida. Born and raised in South Florida, she recently moved to Colorado to join the HNS team. Sabrina has worked in neuropsychology for many years and has extensive experience with neuropsychological assessment. Her experiences encompass working with a variety of populations throughout the lifespan.

Sabrina is compassionate and treats all of her patients with care. Testing can sometimes sound scary; the fear of the unknown is normal. However, making her patients feel safe, heard, and supported is a priority.

Madison recently earned her bachelor's degree from Colorado State University in behavioral and cognitive neuroscience and has previous experience shadowing the pediatric neurosurgeons and PAs at Wolfson Children's Hospital in Jacksonville, Florida.

Madison is a very friendly individual who has worked with kids over the course of her teen years and is excited to interact with youth of all ages as they visit the Horizon office. She hopes she can be another friendly face that welcomes patients into the office and, in one way or another, bring comfort to families as they come in and get the help they deserve.

Lauren Lobsinger will soon graduate from the Metropolitan State University of Denver with the Provost Honor Role of bachelors in psychology and lifestyle medicine. During these studies, she has developed a passion for understanding the brain and body connection. Achieving a doctorate in neuroscience is in the foreseen future. Lauren is also a certified court-appointed special advocate (CASA). In this role, she supports and protects children in abuse/neglect disputes. Lauren upholds the youth's voices through compassion and understanding.

Katharine is a former Resort Activities Recreation Coordinator for Walt Disney Florida. During her time in this role, she developed a wealth of knowledge and skills in elevated business strategies, communication, networking, and event planning. Katharine has returned to Colorado to put these transferable skills to use in her new role as a Practice Manager for Horizon Neuropsychological Services.

Katharine has a Bachelor’s degree in Recreation, Tourism, and Hospitality with an emphasis in Events from the University of Northern Colorado. However, she is looking forward to going back to school to obtain her Master’s in Psychology to further her passion for helping people.

Katharine is excited to assist you and your family as you work with our staff at Horizon Neuropsychological Services to discover your new potential. Her goal is to make you and your family feel as comfortable as possible while visiting our offices.

Savannah earned her bachelor's degree from Colorado State University in health and exercise science with a concentration in sports medicine. She has clinical experience as a Behavioral Technician working with kids on the spectrum.

During her time as a clinician, Savannah has discovered her more profound passion for medicine and is pursuing a future as a Physician Assistant (PA). She hopes to work in the emergency room, where her passion for helping others will impact various patients.

Matt Mullens specializes in software development and system architecture. He is responsible for various technical projects at Horizon Neuro and is applying his experience in a variety of industries across a wide range of technologies to help Horizon Neuro operate more efficiently. He has a deep passion for machine learning and data science and how that applies to the healthcare space. Matt is looking forward to helping Horizon Neuro deliver the best care possible to patients and their families.