The brain, being the “control center” of the body is cushioned by fluid, and is protected by bone and layers of membranes that support blood vessels that feed the brain.
Direct or indirect mechanical impact to the brain may result from sports activities or workplace accidents. These may result in trauma to the brain. Rapid acceleration or deceleration, e.g., motor vehicle accidents or intense changes in pressure, e.g., blast exposures can also lead to brain damage.
The term “concussion” is commonly used to refer to a brain injury resulting from the head being hit with a great deal of force. Shaking the upper body and head violently can also cause brain damage.
Concussions alter the way the brain functions. The effects are usually short-lived, but may include being dazed, headaches, and problems with concentration, memory, balance, and coordination.
Brain injuries may result in loss of consciousness, but since the majority of cases do not end in “blackouts”, concussions often occur without the individual realizing they have had damage. The impact may seem relatively mild, and the individual may appear only to be dazed and with time and rest they may heal properly.
Serious untreated concussions can result in long-term brain damage and may even end in death.
Repetitive head injuries are a major issue especially when an individual sustains additional head injuries before the damage from the prior injury has been completely resolved.
The effects are cumulative. Cumulative sports concussions increase the likelihood of permanent neurologic disability. Complete recovery from an initial trauma can take from 6-18 months, and multiple concussions over time may result in long-term problems, including neurological deterioration, dementia-like symptoms, memory disturbances, behavioral, and personality changes, Parkinsonism, and speech and gait abnormalities.
In a minority of cases, additional trauma to the brain, even occurring from days to weeks following a prior event, can lead to collapse and death within minutes.
How quickly and completely one heals, depends on a number of factors including one’s genetic makeup. (This would be expected since genes determine a cell’s ability to withstand mechanical stress, regenerate, and heal.)
Inflammation and Concussions
For years it was thought that the membranes around the brain acted as a blood-brain barrier which stopped the brain from responding with inflammatory responses when it was confronted by infection. However, it has now been shown that concussions and other brain injuries, or infection or disease, will trigger inflammatory responses.
The types of immune cells found throughout the body are also found in the brain, but additionally, the brain has unique immune cells. When activated, brain-specific microglia and astrocytes, produce inflammatory cytokines that remain localized in the brain.
In response to brain injury, the immune system releases a tidal wave of pro- and anti-inflammatory cytokines, molecules that trigger and/or stop an inflammatory response depending on what is needed.
In small amounts, these cytokines help protect the brain and heal it. However, prolonged exposure to inflammatory cytokines, or too high a level of these proteins, will result in damage that accumulates after injury. High levels of inflammatory cytokines are localized at the injury site, and may be found on the opposite side of the head from the side that was hit.
There is increasing evidence suggesting that much of the neurological damage that occurs after the brain is injured is the result of a delayed inflammatory response that lasts hours, days, or even for months after the injury. This chronic inflammatory response may cause more damage to the brain tissue than the mechanical impact itself.
Immune Homeostasis, Immune Balance is the Key
Unfortunately, pharmaceutical treatments known to reduce inflammation appear to interfere with the brain’s natural repair mechanisms. Therefore it is necessary for the body to control its inflammatory responses. It has to produce enough of a response to help brain tissue heal, but not an overly exaggerated inflammatory response which may cause more damage after injury.
In order for the brain to heal after trauma, the immune system must generate the proper balance, and types, of pro-inflammatory and inflammatory cytokines. For those with brain injuries, maintaining immune homeostasis, immune balance, may be the best way to minimize damage.
Dr. Hellen is available at 302.265.3870 for discussion on the role of inflammation and immune homeostasis in our health. She may be contacted at: firstname.lastname@example.org, or use the contact form. Thank you.