A 45-year-old man with right-sided weakness, poor balance, and cognitive problems 15 months after a left-sided hemorrhagic stroke received 83 hyperbaric oxygen therapy sessions (2.0 ATA, 90 minutes) over 16 weeks. After treatment he improved from wheelchair dependence to walking with a quadruped cane, showed stronger muscles, less spasticity, better balance, and gains in attention, verbal memory, and processing speed. Brain imaging matched these gains: diffusion tensor imaging showed increased white-matter integrity in key tracts, and SPECT showed ~16% increased blood flow in the right motor cortex and right frontal lobe. The case suggests HBOT can boost neuroplasticity and blood flow in nondead brain tissue even long after a stroke, and advanced imaging can track these changes <view study>