Any brain function can be disrupted by brain trauma resulting in inattention, difficulty concentrating, excessive sleepiness, faulty judgment, depression, irritability, emotional outbursts, and slowed thinking. However, memory loss is one of the most common cognitive side effects of traumatic brain injury (TBI). Even in mild TBI, memory loss is still very common. The more severe the victim's memory loss after the TBI, the more significant the brain damage will most likely be.
Some TBI-related amnesia such as patients unable to recall what happened just before, during and after the head injury is temporary. Temporary memory loss is often caused by swelling of the brain in response to the damage it sustained. But because the brain is pressed against the skull, even parts that were not injured are still not able to work. The patient's memory typically returns as the swelling goes down over a period of weeks or even months. Temporary memory loss may also be an emotional response to the stressful events surrounding a TBI.
Damage to the nerves and axons (connection between nerves) of the brain may also result in memory loss. The brain cannot heal itself like an arm or a leg, so any function that is damaged during a TBI is permanently impaired unless the brain learns how to perform that function differently. Fixed amnesia may include the loss of meanings of certain common, everyday objects or words, or a person may not remember skills he had before the TBI.
A different kind of memory loss is called anteretrograde amnesia, which is an inability to form memories of events that happened after the injury. Doctors are not sure, exactly, why this happens, but some research has shown that it may have something to do with the fact that TBI's reduce the levels of a protein in the brain that helps the brain balance its activity. Without enough of that particular protein, the brain can easily overload and memory formation is affected.
In general, symptoms of brain injury should lessen over time as the brain heals but sometimes the symptoms worsen because the patient's inability to adapt to the brain injury. It is not uncommon for psychological symptoms to arise and worsen after a brain injury.
At the current time, there is no treatment for memory loss following TBI; if the memory does not come back on its own, it will be lost permanently. There is a great deal of research in the field of TBI and memory loss, but, sadly, there are no cures for TBI-related amnesia at this time.
