Dr. George J. Counelis is a Board-Certified neurosurgeon who specializes in complex brain and spinal problems. He received his medical training at Tufts University School of Medicine in Boston. After a post-doctoral clinical fellowship in cerebral blood flow at UCLA, he completed his internship and six years of neurosurgical training at the Hospital of the University of Pennsylvania. During his training at the University of Pennsylvania, he completed fellowships in brain tumor research and complex spinal surgery. In 2004, Dr. George J. Counelis joined the medical staff of John Muir Health and was chosen as the Medical Director of the Brain Tumor and Neuro-Oncology Program in 2008.

Dr. Merkow completed medical school at the Columbia University Medical Center. Following medical school, he completed his internship and residency at the Hospital at the University of Pennsylvania. Dr. Merkow received his fellowship training at the Wellington Public Hospital. Dr. Merkow is board certified in Neurosurgery by the American Board of Neurological Surgery. He specializes in minimally invasive spine surgery, brain tumors and functional neurosurgery.

Dr. Chen is certified by the American Board of Neurological Surgery. He received his medical training at the Yale University School of Medicine, where he also completed his internship and residency. Dr. Chen is a neurosurgeon at John Muir Health where he specializes in minimally invasive approaches to the spine, tumors of the brain and spine, and cervical spine disease.

Dr. Piazza is a neurosurgeon who specializes in surgical treatment of diseases of the spinal column and nervous system.  Dr. Piazza completed medical school at Columbia University Medical Center.  Following medical school, he completed residency training and a fellowship at University of Pennsylvania.

Cristina received her Bachelor's Degree in Business in 1994 and her Associate's Degree in Nursing from Los Medanos College. She began her career as an Oncology Nurse in 2009 and earned her Radiation Therapy Certificate in 2012. She has been a Nurse Navigator in Radiation Oncology at John Muir Health since 2012, and is currently studying for her Oncology Certification.

Darcel received her Bachelor's Degree in Dietetics from California State University at Chico. She is a Certified Faith Community Nurse and currently works as a dedicated Nurse Navigator at John Muir Health.