Depictions of head-injury patients in movies and television almost always show the patient experiencing some type of amnesia, or memory loss. Indeed, memory loss is the most common cognitive side effect of a severe traumatic brain injury. In patients with a milder TBI, memory loss is still one of the most common symptoms. And the more severe the patient's memory loss is, the more severe the brain damage is likely to be.

Temporary Memory Loss and TBI

Some traumatic brain injury-related amnesia is temporary; such patients are usually unable to recall what happened directly before, during and after their accidents. This is often caused by edema, or a swelling of the brain in response to the damage it sustained. Because the brain is pressed against the skull, parts that were not injured are still not able to work. As the swelling goes down, the patient's memory returns, often slowly over a period of weeks, months or even years. Temporary memory loss may also be an emotional response to the stress of the event that caused the TBI.

Other, less common, types of memory loss stemming from traumatic brain injury are fixed. These result from damage to the nerves and axons (connections between nerves) of the brain itself. Because the brain cannot heal itself like an arm or a leg, any function that is damaged during a TBI is permanently impaired unless the brain can learn to perform that function differently. Fixed amnesia may include inability to remember events before the injury, or loss of memory of the meanings of certain things, such as words or smells or objects. Less commonly, a person may not remember skills he or she had before the TBI.

Brain Damage and Anteretrograde Amnesia

A patient with TBI may also develop anteretrograde amnesia -- an inability to form memories of events that happened after the injury. The reason for this is not well understood, but an October 2006 study by researchers at the Children's Hospital of Philadelphia found that TBIs reduce the levels of a protein in the brain that helps it balance its activity. Without enough of that protein, the brain can "overload," the researchers said, interfering with memory formation, particularly the ability to learn new things.

Treatment Options for Traumatic Brain Injury Patients with Amnesia

There is no treatment for memory loss caused by a traumatic brain injury; if the memory does not come back on its own, it is gone forever. However, a September 2006 study published in Neurology, the scientific journal of the American Academy of Neurology, showed promising results in TBI patients with anteretrograde memory loss who took the drug rivastigmine. The drug, which is sold to Alzheimer's disease patients under the brand name Exelon, helped patients with moderate to severe memory loss score better on memory tests than another group of patients that took placebos. The results were not as good for patients who had only mild memory loss. If you suffer from traumatic brain injury-related memory problems, you may wish to contact an experienced TBI attorney to discuss your options, which may include filing a brain injury lawsuit in order to gain compensation for your medical costs.