When the brain is damaged – pierced, hit, bruised, swollen, herniated or subjected to lack of oxygen – the precise area damaged and the severity of the injury will result in widely varying symptoms. Traumatic brain injury is usually diagnosed by degrees – mild, moderate, or severe. All have long-term effects.

Frontal Lobe: This area of the brain controls problem solving, judgment, inhibition of behavior, planning, emotion, personality, mental flexibility, ability to express oneself through speech, and organizational capacity.

Temporal Lobe: The temporal lobe is involved in memory functions, hearing, speech comprehension and sequencing.

Parietal Lobe: The parietal lobe of the brain gives us our sense of touch, as well as spatial and visual perception.

Occipital Lobe: Vision is controlled by the occipital lobe.

Cerebellum: Balance, coordination, and motor skill activities depend on the cerebellum.

Brain Stem: The brain stem manages critical and life sustaining body functions including breathing, heart rate, sleep and wake cycles, concentration, and consciousness.

Damage to any one of these areas can seriously and permanently affect the injured person.

Mild TBI: People with mild TBI may suffer from headache, confusion, changed sleep patterns, behavior and mood changes, memory loss, poor concentration, and difficulty with thinking.

Moderate or Severe TBI: Those suffering from moderate or severe TBI may have the above symptoms plus others including worsening or continuous headache, vomiting or nausea, convulsions, slurred speech, numbness in the extremities, loss of coordination, restlessness, or agitation. The worst injuries result in stupor, coma, or a persistent vegetative state.

Closed head injuries are a common result when a blunt object strikes the skull but does not penetrate it. Such traumatic injuries can range widely in severity, including a mild concussion, death, and all variations in between. In the past, doctors largely believed that a closed head injury was less serious than a penetrating injury because it did not involve a fracture of the skull. Experience has since shown that the closed head injury can be every bit as severe as the penetrating injury because of brain swelling and inflammation.

When the brain is injured, it swells. With a penetrating injury, there is the potential that the fracture can help prevent damage because the skull is able to expand to accommodate the swollen tissue. In the case of a closed head injury, however, the skull is not fractured and cannot expand. Thus, the swelling brain tissue builds up pressure—and neural damage—as it compresses the brain against the rigid, fixed and unyielding walls of the skull.

The damage from a closed head injury ranges on a spectrum of severity. Less serious injuries may result in feeling “dazed” or in momentary losses of consciousness; other possible symptoms include blurred vision or headaches. On the serious end of the spectrum, people can lose consciousness for hours, days, or even longer (for more information on brain injuries and coma. Seizures may also result (for more information on traumatic brain injuries and seizures.