Dementia in Head Injury
Dementia after a head injury is a significant public health problem.
- In the United States, roughly 2 per 1,000 people each year have some kind of head injury. Many do not seek medical care.
- Between 400,000 and 500,000 people are hospitalized in the U.S. every year for head injury.
- Younger people are more likely to have a head injury than older people. Head injury is the third most common cause of dementia, after infection and alcoholism, in people younger than 50 years.
- Older people with head injury are more likely to have complications such as dementia. Children are likely to have more severe complications.
- Men, especially younger men, are more likely than women to have a head injury.
The nature of dementia in head-injured persons varies greatly by type and location of head injury and the person's characteristics before the head injury.
The dementia that follows a head injury differs from other types of dementia. Many types of dementia, such as Alzheimer's disease, get steadily worse over time. Dementia from head injury usually does not get worse over time. It may even improve somewhat over time. The improvement usually is slow and gradual and takes months or years.
Dementia and Causes of Head Injury
The following are the most common causes of head injury in civilians:
- Motor vehicle accidents (50%)
- Falls (21%)
- Assault or gunshot wound (12%)
- Sports, such as boxing or other recreational activity (10%)
Use of alcohol or other substances is a factor in about half of these injuries.
Certain groups are more likely than others to sustain head injury:
- In children, bicycle accidents are a significant cause of head injury.
- Most head injuries in infants reflect child abuse. A common name for this is shaken baby syndrome.
- Older adults are especially likely to injure themselves by falling.
Symptoms of Dementia in Head Injury
Dementia-related symptoms in head injury include those that affect thinking and concentration, memory, communication, personality, interactions with others, mood, and behavior.
Individuals experience different combinations of these symptoms depending on the part of the head injured, the force of the blow, the damage caused, and the person’s personality before the injury. Some symptoms appear rapidly, while others develop more slowly. In most cases, symptoms have at least started to appear in the first month after the injury.
Symptoms of dementia in people with head injuries include:
- Problems thinking clearly
- Memory loss
- Poor concentration
- Slowed thought processes
- Irritability, easily frustrated
- Impulsive behavior
- Mood swings
- Inappropriate behavior in social situations
- Grooming and dressing eccentric or neglected
- Restlessness or agitation
- Aggression, combativeness, or hostility
- Vague, nonspecific physical symptoms
Some people develop seizures after a head injury. These are not part of the dementia, but they can complicate the diagnosis and treatment of dementia.