Leadership & Physicians

Driving our mission to return patients to lives of productivity and meaning are our leadership team, physicians, and clinicians. The entire Nexus Health Systems family is committed to mending minds and helping our patients and their families during the recovery process.


Erin Cassidy



John Cassidy, MD

Founder, Chief Executive Officer, Chief Medical Officer


Dr. John W. Cassidy is certified by the American Board of Psychiatry and Neurology and has over 30 years of experience in clinical neuroscience and neurobehavioral rehabilitation programs. Currently operating as CEO and Chief Medical Officer of Nexus Health Systems – which he founded in 1992 – Dr. Cassidy was previously the Psychiatrist in Charge and Co-Founder of the Neuropsychiatry Program at McLean Hospital; Chief Medical Officer and Founder of the Neurobehavioral Institute of Houston; Director and Founder of the Neuropsychiatry Subspecialty Services of Del Oro Rehabilitation Hospital; and Medical Director of Neurobehavioral Programs at Cypress Creek Hospital.

Devoting his career to improving the understanding and treatment of individuals with acquired and traumatic brain injuries, Dr. Cassidy continues to help patients return to productive and meaningful lives through a neurospecialty continuum of care. His comprehensive rehabilitative approach delivers more than traditional therapies, addressing a person’s interpersonal, behavioral, cognitive, physical, and emotional challenges to ensure a more successful rehabilitation journey and clinical outcome.

Dr. Cassidy received his Bachelor of the Arts from Hiram College and Doctor of Medicine from the University of Cincinnati College of Medicine. In addition, he received his post-graduate training at Harvard Medical School. Dr. Cassidy has spoken nationally and internationally about the sequela and management of severe traumatic brain injury and authored three books and a number of papers, book chapters, and editorials.


Joel Talley

Chief Operations Officer


John Raley

VP of Revenue Cycle


Kim Fields

VP of Finance


Kevin McAndrews

VP of Human Resources


Lee Brumbaugh

VP of Sales


Virginia Barry

VP of Quality


Mikael Simpson

CEO Nexus Neurorecovery Center


Eric Cantrell

CEO Nexus Specialty Hospital

Nexus Physician Services

Since its inception in 2014, Nexus Physician Services has recruited physicians and physician extenders, including nurse practitioners and physician assistants, who have specialized education and training. Additionally, our physicians are board certified in a variety of specialties that permit medical interdisciplinary treatment of our patients, including: neurology, psychiatry, neuropsychiatry, pediatric neuropsychiatry and adult and pediatric physical medicine and rehabilitation.

Exclusively caring for our neurospecialty patients full-time, Nexus Physician Services represents a group of doctors who are dedicated to furthering our neurocontinuum of care and supporting our patients and their families. Additionally, these physicians educate our staff and community through continuing education presentations, grand rounds, and other educational opportunities.

Physicians associated with this elite group are aligned to Nexus’ standards and treatment philosophy. All doctors who are a part of Nexus Physician Services are under our supervision and clinically report to Dr. John Cassidy, Chief Medical Officer.

Services Include:

  • Impatient and outpatient consultation
  • Record review
  • Legal case review
  • Pre-program placement comprehensive assessment
  • Program recommendations

Journey Toward Independence

Nexus' NeuroContinuum sequence provides a range of care for those recovering from acquired or traumatic brain injuries and other complicated illnesses or diseases.
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