The brain is what makes us human, so it is understandable that people fear the wide-ranging symptoms that can accompany brain injury. These symptoms include impaired motor functions, loss of memory, loss of sight, loss of hearing, personality changes, depression, aggression and many more. These are frightening, and many of the symptoms, like personality changes, are hard for people to understand. Unfortunately, traumatic brain injuries (TBI) are common. The Center for Disease Control estimates that 1.7 million people a year sustain some form of brain injury. This number does not reflect the number of people who sustain minor brain injuries but never seek treatment. It is understandable why traumatic brain injury is so worrisome -- especially to high-risk groups [ CDC: TBI page ].Stem cells are here to save everyone from traumatic brain injury...maybe. According to research led by Toshiya Osanai of Hokkaido University and published in the February issue of “Neurosurgery,” stems cells injected into the carotid artery of rats that had sustained traumatic brain injuries led to significant improvements of motor functions over a control group. The stem cells were uncontroversial -- taken from the rats’ bone marrow and labeled with quantum dots to allow tracking. After the injection, the stem cells entered and dispersed throughout the brain; eventually, the stem cells transformed into different brain cells and patched the brain injury sites [ Science Daily: TBI ].This is promising research, and since it takes stems cells from an uncontroversial source, it is possible for this research to advance and spread faster than research using controversial sources of stem cells. Yet one of the main questions is who will this research benefit the most?Of course, this research would benefit anyone with traumatic brain injuries, but it has the potential to help the elderly and the military the most. The elderly, 65 years and older, have the highest rates of traumatic brain injuries, usually resulting from falls. The brains’ of elderly patients also have the least ability to repair themselves. As for the military, veterans groups have suggested that 10 to 20 percent of Iraqi veterans have sustained some level of traumatic brain injury, and a congressional report stated that as of 2010, there were 178,876 cases of traumatic brain injury from combat [ Congressional Research Services ]. This new treatment is very likely to be useful to these groups.The researchers also believe of this work could help stroke victims. Strokes are very common. According to the CDC, there are about 795,000 strokes a year in the US. Strokes are also a leading cause of long-term disability and death. The researchers have not demonstrated that the treatment can work on strokes, but it seems reasonable to assume that the new treatment could provide some relief. However, there is a major difference between traumatic brain injuries and strokes. The cause of traumatic brain injury is external. Strokes usually occur after many years of an unhealthy lifestyle putting stress on the blood vessels; therefore, unlike traumatic brain injuries, strokes are likely to reoccur [ CDC: stroke ].The treatment might be able to go one-step further and treat the symptoms of brain diseases, like Alzheimer’s disease, Huntington’s disease, Parkinson’s disease and muscular dystrophy. These diseases are usually responsible for killing certain parts of the brain and present with a wide array of symptoms. This new stem cell treatment would not be able to cure these diseases; however, the treatment might be able to continually repair the damage done by these diseases, extending the quality of life for the patient. For this to work, however, the researchers need to determine if there is a limited time span between brain injury and stem cell injection for the stem cells to work. If there were a limited time span between brain damage and treatment, this new treatment’s effectiveness would be reduced for these diseases since they can go undiagnosed for years.