Closed-head injury is a type of
traumatic brain injury
A traumatic brain injury (TBI), also known as an intracranial injury, is an injury to the brain caused by an external force. TBI can be classified based on severity (ranging from mild traumatic brain injury TBI/concussionto severe traumatic b ...
in which the skull and dura mater remain intact. Closed-head injuries are the leading cause of death in children under 4 years old and the most common cause of physical disability and cognitive impairment in young people.
Overall, closed-head injuries and other forms of
mild traumatic brain injury
A concussion, also known as a mild traumatic brain injury (mTBI), is a head injury that temporarily affects brain functioning. Symptoms may include loss of consciousness (LOC); memory loss; headaches; difficulty with thinking, concentration, ...
account for about 75% of the estimated 1.7 million brain injuries that occur annually in the United States.
Brain injuries such as closed-head injuries may result in lifelong physical, cognitive, or psychological impairment and, thus, are of utmost concern with regards to public health.
Symptoms
If symptoms of a head injury are seen after an accident, medical care is necessary to diagnose and treat the injury. Without medical attention, injuries can progress and cause further brain damage, disability, or death.
Common symptoms
Because the brain swelling that produces these symptoms is often a slow process, these symptoms may not surface for days to weeks after the injury.
[http://www.allabouttbi.com/symptoms.htm]
Common symptoms of a closed-head injury include:
*headache
*dizziness
*nausea
*vomiting
*slurred speech
Severe injury symptoms
Severe head injuries can lead to permanent vegetative states or death, therefore being able to recognize symptoms and get medical attention is very important. Symptoms of a severe closed-head injury include:
*coma or vegetative states
*seizures or convulsions
*loss of consciousness
Secondary symptoms
Secondary symptoms are symptoms that surface during rehabilitation from the injury including social competence issues, depression, personality changes, cognitive disabilities,
anxiety
Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different than fear in that the former is defined as the anticipation of a future threat wh ...
, and changes in sensory perception. More than 50% of patients who suffer from a traumatic brain injury will develop psychiatric disturbances.
Although precise rates of anxiety after brain injury are unknown, a 30-year follow-up study of 60 patients found 8.3% of patients developed a panic disorder, 1.7% developed an anxiety disorder, and 8.3% developed a specific phobia.
Patients recovering from a closed-head or traumatic brain injury often suffer from decreased self-esteem and depression. This effect is often attributed to difficulties re-entering society and frustration with the rehabilitation process. Patients who have suffered head injuries also show higher levels of unemployment, which can lead to the development of secondary symptoms.
Causes
Closed-head injuries are caused primarily by vehicular accidents, falls, acts of violence, and sports injuries.
[ Falls account for 35.2% of brain injuries in the United States, with rates highest for children ages 0–4 years and adults ages 75 years and older.][ Head injuries are more common in men than women across every age group.][ Boys aged 0–4 years have the highest rates of brain injury related hospital visits, hospitalizations, and deaths combined.][ Multiple mild traumatic brain injuries sustained over a short period of time (hours to weeks), often seen with sports-related injuries, can result in major neurological or cognitive deficits or fatality.]
Blast-related traumatic brain injuries are often closed-head injuries and result from rapid changes in atmospheric pressure, objects dislodged by the blast hitting people, or people being thrown into motion by the blast Blast-related injuries have shown a recent increase in occurrence with the return of veterans from Iraq such that traumatic brain injury has been coined the "signature injury" of Operation Iraqi Freedom
Closed-head injuries can range from mild injuries to debilitating traumatic brain injuries and can lead to severe brain damage or death. Common closed-head injuries include:
*concussion
A concussion, also known as a mild traumatic brain injury (mTBI), is a head injury that temporarily affects brain functioning. Symptoms may include loss of consciousness (LOC); memory loss; headaches; difficulty with thinking, concentration, ...
– a head injury resulting in temporary dysfunction of normal brain function. Almost half of the total concussions reported each year are sports-related
*intracranial hematoma
Intracranial hemorrhage (ICH), also known as intracranial bleed, is bleeding within the skull. Subtypes are intracerebral bleeds ( intraventricular bleeds and intraparenchymal bleeds), subarachnoid bleeds, epidural bleeds, and subdural bleeds. ...
– a condition in which a blood vessel ruptures causing a pool of blood to form around the brain (subdural hematoma) or between the brain and the skull (epidural hematoma). Intracranial hematoma causes an increase in pressure on the brain and requires immediate medical attention.
*cerebral contusion
Cerebral contusion, Latin ''contusio cerebri'', a form of traumatic brain injury, is a bruise of the brain tissue.
Like bruises in other tissues, cerebral contusion can be associated with multiple microhemorrhages, small blood vessel leaks into ...
– a bruise to the brain tissue as a result of trauma. Contusions are local in nature, separating them from concussions.[
*]diffuse axonal injury
Diffuse axonal injury (DAI) is a brain injury in which scattered lesions occur over a widespread area in white matter tracts as well as grey matter. DAI is one of the most common and devastating types of traumatic brain injury and is a major cause ...
– These injuries are frequently seen in car accidents and cause permanent damage to the brain. Severe diffuse axonal injuries often lead to comas or vegetative states.
Diagnosis
Classification
Glasgow Coma Scale
The Glasgow Coma Scale
The Glasgow Coma Scale (GCS) is a clinical scale used to reliably measure a person's level of consciousness after a brain injury.
The GCS assesses a person based on their ability to perform eye movements, speak, and move their body. These thre ...
is commonly used to assess the severity of traumatic brain injuries, including closed-head injuries. The scale tests a patient's eye, verbal, and motor responses. The scale goes up to fifteen points; with fifteen being the most mild injury, less than eight being a severe brain injury, and three being a vegetative state.
ASCOT
The ASCOT probability of survival encapsulates several of the variables measured in the Glasgow Coma Scale but also includes systolic blood pressure, respiration rates upon admission, and anatomic injuries. The ASCOT was found to be the most sensitive tool for determining severity of head injuries in children and is effective in predicting the outcome of injury.
Mechanism based
A mechanism-based TBI classification system divides traumatic brain injuries (TBI) into closed and penetrating head trauma
A penetrating head injury, or open head injury, is a head injury in which the dura mater, the outer layer of the meninges, is breached.University of Vermont College of Medicine"Neuropathology: Trauma to the CNS."Accessed through web archive on Aug ...
; based on the way in which the person was injured.
Treatments
There are several different types of treatment available to those who have suffered a closed-head injury. The treatment type chosen can depend on several factors including the type and severity of injury as well as the effects that injury has on the patient.
The course of treatment differs for each patient and can include several types of treatment, depending on the patient's specific needs.
Early treatment is vital to recovering lost motor function after an injury, but cognitive abilities can be recovered regardless of time past since injury.
Pharmacotherapy
Pharmacotherapy
Pharmacotherapy is therapy using pharmaceutical drugs, as distinguished from therapy using surgery (surgical therapy), radiation (radiation therapy), movement ( physical therapy), or other modes. Among physicians, sometimes the term ''medical the ...
is the utilization of drugs to treat an illness. There are several different drugs that have been used to alleviate symptoms experienced after a head injury including anti-depressants
Antidepressants are a class of medication used to treat major depressive disorder, anxiety disorders, chronic pain conditions, and to help manage addictions. Common side-effects of antidepressants include dry mouth, weight gain, dizziness, heada ...
such as amitriptyline and sertraline. Use of these drugs has been associated with a decrease in depression and increased functioning in social and work environments.[ An ]antidiuretic
An antidiuretic is a substance that helps to control fluid balance in an animal's body by reducing urination, opposing diuresis. Its effects are opposite that of a diuretic. The major endogenous antidiuretics are antidiuretic hormone (ADH; also ca ...
called Desmopressin Acetate (DDAVP) has also been shown to improve memory performance in patients[
Recent studies have examined the preventative effects of ]progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the m ...
on brain injuries. Phase III trials are currently being conducted at 17 medical centers across the United States. Preliminary results have shown a 50% reduction in mortality in those treated with progesterone and showed an improved functional outcome.
Overall, the efficacy of pharmacotherapeutic treatments is dependent on the treatment being used and the symptoms being targeted by the treatment.
Patient education
Patient education has been shown to be one of the most effective ways to decrease secondary symptoms seen with closed-head injuries. Patient education often includes working with a therapist to review symptom management and learn about returning to regular activities.[ Educational initiatives have also been shown to decrease the occurrence of ]PTSD
Post-traumatic stress disorder (PTSD) is a mental and behavioral disorder that can develop because of exposure to a traumatic event, such as sexual assault, warfare, traffic collisions, child abuse, domestic violence, or other threats on a ...
in head-injury survivors.[
]
Cognitive rehabilitation
Many patients with severe injuries need therapy to regain basic motor and cognitive skills. Cognitive rehabilitation
Rehabilitation or Rehab may refer to:
Health
* Rehabilitation (neuropsychology), therapy to regain or improve neurocognitive function that has been lost or diminished
* Rehabilitation (wildlife), treatment of injured wildlife so they can be retur ...
aims to improve attention, memory function, and cognitive-processing speed. The type of rehabilitation used is tailored to the patient's clinical needs depending on the severity and type of injury sustained.[
]
Other
Other types of rehabilitation focus on raising patient's self-esteem by giving him tasks that can be successfully completed despite any cognitive changes as a result of the brain injury. This process can help decrease secondary symptoms such as feelings of worthlessness, depression, and social anxiety.[http://whqlibdoc.who.int/hq/2004/WHO_DAR_01.9_eng.pdf] Some rehabilitation programs use team-building exercises and problem-solving activities to help the patients learn to work with their disabilities.[
]
Prevention
Many closed-head injuries can be prevented by proper use of safety equipment during dangerous activities. Common safety features that can reduce the likelihood of experiencing a brain injury include helmets, hard hats, car seats, and safety belts. Another safety precaution that can decrease a person's risk for brain injury is ''not'' to drink and drive or allow oneself to be driven by a person who has been drinking or who is otherwise impaired.
Helmets can be used to decrease closed-head injuries acquired during athletic activities, and are considered necessary for sports such as American "tackle" football, where frequent head impacts are a normal part of the game. However, recent studies have questioned the effectiveness of even American football helmets, where the assumed protection of helmets promotes far more head impacts, a behavior known as risk compensation
Risk compensation is a theory which suggests that people typically adjust their behavior in response to perceived levels of risk, becoming more careful where they sense greater risk and less careful if they feel more protected. Although usually ...
. The net result seems to have been an increase, not decrease, in injuries. The similar sports of Australian-rules football and rugby are always played helmetless, and see far fewer traumatic brain injuries. (See Australian rules football injuries
Australian rules football is a sport known for its high level of physical body contact compared to other ball sports such as soccer and basketball. High-impact collisions can occur from any direction, although deliberate collisions sometimes occur ...
.)
Bicycle helmet
A bicycle helmet is a type of helmet designed to attenuate impacts to the head of a cyclist in falls while minimizing side effects such as interference with peripheral vision. There is ongoing scientific research into the degree of protection ...
s are perhaps the most promoted variety of helmet, based on the assumption that cycling without a helmet is a dangerous activity, with a large risk of serious brain injury. However, available data clearly shows that to be false. Cycling (with approximately 700 American fatalities per year from all medical causes) is a very minor source of fatal traumatic brain injury, whose American total is approximately 52,000 per year. Similarly, bicycling causes only 3% of America's non-fatal traumatic brain injury.
Still, bicycle-helmet promotion campaigns are common, and many U.S jurisdictions have enacted mandatory bicycle-helmet laws for children. A few such jurisdictions, a few Canadian provinces, plus Australia and New Zealand mandate bicycle helmets even for adults. A bicycle-helmet educational campaign directed toward children claimed an increase in helmet use from 5.5% to 40.2% leading to a claimed decrease in bicycle-related head injuries by nearly 67%. However, other sources have shown that bicycle-helmet promotion reduces cycling, often with no per-cyclist reduction in traumatic brain injury.
Estimates of bicycle-helmet use by American adults vary. One study found that only 25-30% of American adults wear helmets while riding bicycles, despite decades of promotion and despite sport cyclists' adoption of helmets as part of their uniform.
Following the commercial (as opposed to public-health) success of bicycle helmets, there have been successful attempts to promote the sale of ski helmet
A ski helmet is a helmet specifically designed and constructed for winter sports. Use was rare until about 2000, but by about 2010 the great majority of skiers and snowboarders in the US and Europe wear helmets. Helmets are available in many styles ...
s. Again, results have been less than impressive, with great increases in helmet use yielding no reduction in fatalities, and with most injury reduction confined to lacerations, contusions, and minor concussions, as opposed to more serious head injuries.
There have been rare campaigns for motoring helmets.[http://casr.adelaide.edu.au/developments/headband/] Unfortunately, just as people greatly overestimate the traumatic brain injury danger of bicycling, they greatly underestimate the risk of motoring, which remains the largest source of traumatic brain injury in the developed world, despite the protective effects of seatbelts and airbags.
See also
*Cerebral contusion
Cerebral contusion, Latin ''contusio cerebri'', a form of traumatic brain injury, is a bruise of the brain tissue.
Like bruises in other tissues, cerebral contusion can be associated with multiple microhemorrhages, small blood vessel leaks into ...
*Concussion
A concussion, also known as a mild traumatic brain injury (mTBI), is a head injury that temporarily affects brain functioning. Symptoms may include loss of consciousness (LOC); memory loss; headaches; difficulty with thinking, concentration, ...
*Diffuse axonal injury
Diffuse axonal injury (DAI) is a brain injury in which scattered lesions occur over a widespread area in white matter tracts as well as grey matter. DAI is one of the most common and devastating types of traumatic brain injury and is a major cause ...
*Intracranial hemorrhage
Intracranial hemorrhage (ICH), also known as intracranial bleed, is bleeding within the skull. Subtypes are intracerebral bleeds ( intraventricular bleeds and intraparenchymal bleeds), subarachnoid bleeds, epidural bleeds, and subdural bleeds. ...
*Traumatic brain injury
A traumatic brain injury (TBI), also known as an intracranial injury, is an injury to the brain caused by an external force. TBI can be classified based on severity (ranging from mild traumatic brain injury TBI/concussionto severe traumatic b ...
References
{{reflist
Neurotrauma