Effects of Brain Injury

Traumatic brain injury (TBI), a form of acquired brain injury, occurs when a sudden trauma causes damage to the brain.  A TBI is caused by a bump, blow or jolt to the head or a penetrating head injury that disrupts the normal function of the brain.  Symptoms of a TBI can be mild, moderate, or severe, depending on the extent of the damage to the brain.  A person with a mild TBI may have a brief change in mental status of consciousness.  A severe TBI may experience an extended period of unconsciousness or amnesia after the injury.

It has long been suspected that repetitive head injury can have consequences well into the future.  Studies that have focused on athletes, in particular, have found correlation between repetitive head injury and brain disease occurring years later, long after their athletic careers are over.

There are a wide variety of effects that results from brain injury, and they vary in both duration in type.  As a general rule of thumb, the more severe the brain injury, the more permanent and debilitating damage will result.  Effects can be immediate or long term, and can be physical, cognitive, or emotional.

Mild Traumatic Brain Injury

Mild TBI symptoms are especially subtle and varied.  Victims may lose consciousness for only a few seconds or minutes, or may not lose consciousness at all.  In fact, a mild brain injury victim may be temporarily dazed or remain completely awake.  Mild traumatic brain injury symptoms may not be immediately apparent.  Since the brain swelling that causes many of these symptoms is often gradual, days or weeks can pass before symptoms appear.

Moderate to Severe Traumatic Brain Injury

Moderate to severe traumatic brain injury symptoms are more pronounced.  Moderate to severe traumatic brain injury victims may experience symptoms such as headache that worsens or does not go away, loss of consciousness more than 20 minutes, vomiting, loss of bowel control, slurred speech, memory loss, convulsions, seizures, paralysis, and or numbness in the limbs.  Bleeding in the head is also common and can be measured by an MRI or CT scan.  Even when treated, intracranial bleeding (ICP) can lead to long term complications or death.  Moderate to severe brain injury victims often lose consciousness, and some do not regain consciousness.  Brain injury victims can remain unconscious for days or even weeks before responding to stimuli.
When the pressure within the skull (intracranial pressure) rises too high, it can be deadly.  Signs of increased ICP include decreasing level of consciousness, paralysis or weakness on one side of the body, and a blown pupil, one that fails to constrict in response to light or is slow to do so.  Cushing’s triad, a slow heart rate with high blood pressure and respiratory depression is a classic manifestation of significantly raised ICP.

Common long-term symptoms of moderate to severe TBI are changes in appropriate social behavior, deficits in social judgment, and cognitive changes, especially problems with sustained attention, processing speed, and executive functioning.  Alexithymia, a deficiency in identifying, understanding, processing, and describing emotions occurs in 60.9% of individuals with TBI.  Cognitive and social deficits have long-term consequences for the daily lives of people with moderate to severe TBI, but can be improved with appropriate rehabilitation.

Small children with moderate to severe TBI may have some of these symptoms but have difficulty communicating them.  Other signs seen in young children include persistent crying, inability to be consoled, listlessness, refusal to nurse or eat, and irritability.

It can be difficult to recognize symptoms of mild, moderate, or severe traumatic brain injury.  Subtle symptoms can conceal serious brain damage, so immediate medical care is crucial to diagnose, treat, and cope with traumatic brain injury.