Countless numbers of families have gone through the experience of being told a loved one has suffered a devastating brain injury, and not to expect miracles when it comes to recovery. In many cases, patients have proved their doctors and therapists wrong with unbelievable comebacks. These inspiring stories remind us that there is still much we don't know about the body's capacity to repair itself.

One such case involves a former Marine currently from Sunnyvale, California. Ever since he was involved in a 1991 car accident while he was stationed in Saudi Arabia during Operation Desert Storm, the 47-year-old has been fighting to reclaim the parts of him that the head-on collision took away.

The man's injuries were so serious that his family was discouraged from visiting him in the hospital in Germany where he was taken after the accident; he wasn't expected to survive. When he finally came out of a coma five months later, he needed a wheelchair to compensate for the weakness in his left side. He was also legally blind and had to learn how to speak again. Despite these brain-injury-related setbacks, he has never stopped fighting. Several times a week he reports for physical therapy at a facility in San Jose, and one of his current goals is to complete a vocational training program that could allow him to work again -- possibly with a police department, a lifelong dream that inspired his decision to join the Marines in the first place.

Researchers at UCLA's Fielding School of Public Health conducted a survey of 1,000 residents of central California, all adults age 35 and older. Of them, nearly 35 percent were diagnosed with Parkinson's disease, a disorder with symptoms such as tremors and loss of coordination. The study, released last week, found that those with Parkinson's were twice as likely as those without to report having suffered a head injury at some point, and having lost consciousness for more than five minutes.

Those with the disorder were also more likely to live within 500 meters of a location where the herbicide paraquat was used. Paraquat is used to kill weeds and plants.

Either condition could contribute to the development of Parkinson's disease; however, it seems when both factors are involved, the risk is higher. The reason for this appears to be that earlier head injury makes brain cells vulnerable to this particular poison used on plants. This is clearly something for those diagnosed with the disease to consider in their individual case.

When a 39-year-old San Jose woman left home on the morning of just another normal day, she didn't know she would be involved in a crash that would leave her in critical condition. No one expects tragedy to strike as they go about the everyday routines of daily life, yet brain injuries like the one this woman suffered do happen -- even in such a typical exchange as being cut off by another driveway on a highway.

The woman was driving a Toyota Camry when she swerved to avoid colliding with a driver who cut her off around 5 a.m. The Toyota then rolled several times before landing sideways across the fast lane and median, with traffic coming at the passenger side of the car. Her car was broadsided when another driver in a Toyota MR2 struck her stopped vehicle. She was subsequently rushed to a nearby hospital and was in critical condition after being diagnosed with serious head trauma.

The driver who initially cut off the woman in the Camry sped away, never stopping. The California Highway Patrol has no information regarding that vehicle.

There are countless ways to suffer a brain injury. Car accidents, combat and contact sports have all led to problems ranging from mild concussions to comas. Much to the frustration of both doctors and patients, there are also countless possibilities when it comes to healing from those injuries. It can be nearly impossible to determine when, if, and how long it will take for someone to completely recover.

Thanks to two wars and several lawsuits against the NFL, we're more aware than ever of the impact that a traumatic brain injury can have. But the scope of these injuries isn't limited to veterans and professional football players. Athletes at every level down to peewee soccer are susceptible to long-term effects of a serious bump on the head. Accident victims, too, can suffer the effects of a head injury without realizing how badly they've been hurt.

But a new set of guidelines from the American Academy of Neurology could change how we approach treatment of TBI, particularly when it comes to athletics. The academy plans to release its first comprehensive set of recommendations since 1997 at the end of this year. The report promises to include risk factors for athletes, how brain injuries are diagnosed, what factors can affect recovery and ways to determine when it's safe for athletes to return to the field. These guidelines could bring changes to sports leagues nationwide and prevent players from suffering serious damage.

Many times after a car accident, it can be hard to detect all of a patient's injuries. In some cases accident victims come to the emergency room feeling little to no pain. But that doesn't mean problems can't crop up later, particularly in the case of brain injuries. Because these injuries can be difficult to pinpoint, many patients are given cranial computed tomography, or CT scans.

How do emergency room doctors determine whether a patient should receive a CT scan? That was one of the many questions raised in a study by a professor from the University of California Davis. The study, which was published this month in the Archives of Pediatrics & Adolescent Medicine, found that children with minor blunt head trauma are much less likely to receive a CT scan during an emergency room visit than nonminority children with the same risk.

Minor head trauma carries a low to intermediate risk of "clinically important" traumatic brain injury, according to the study, which examined the connection between race and CT use at hospitals using data from almost 40,000 cases of children who were seen within 24 hours of their injury. The children were white non-Hispanic, black-non-Hispanic or Hispanic. The severity of the children's injuries were described using a previously validated means of classifying each child's risk of TBI.