Dr. Berger's main clinical interests are the treatment of brain tumors in adults and children and of epilepsy related to brain tumors. He has extensive expertise in intraoperative mapping of the brain to identify the sites of motor, sensory, and language function and thereby avoid their involvement or injury during surgery. Dr. Berger is Director of the Adult Hydrocephalus and Shunt Program, and he also practices in the Neuro-Oncology Program and the Radiosurgery Program.

His current research interests involve identifying molecular markers in gliomas as correlates of tumor progression and prognosis. This is done in conjunction with the Molecular Marker Core of the BTRC. He also works in conjunction with Dr. Krys Bankiewicz to test small molecule inhibitors in brain tumors using the drug delivery technique of convection enhanced delivery. He is a co-investigator with Dr. John Park in UCSF's Comprehensive Cancer Center to develop immunoliposome-directed targeted therapy for treating gliomas that express EGF receptors. Other collaborations include functional mapping localization of language pathways in the brain in conjunction with Dr. Robert Knight and the Cognitive Neuroscience Graduate Program at UC Berkeley. Dr. Berger is currently the Principal Investigator of UCSF's SPORE Brain Tumor Program, funded by the National Cancer Institute and NINDS.