By your description, your brother unfortunately developed a burst fracture of C5 that injured the spinal cord. I assume that the water was too shallow and he impacted his head against the bottom causing this fracture.
Cord injuries generally do not have a good prognosis unless there is still some sensation below the injury that is preserved (called sacral sparing). It is my practice to decompress the cord as soon as possible but even with surgery, there is no guarantee of any return of function.
There is research ongoing to try and restore some function to the cord but this research is still in its infancy.
Dr. Corenman
