Concussion / Closed Head Trauma
Condition: Concussion / Closed Head Trauma
Prevalence: At least 1.5 million/year; 320,000 severe
Layman’s Definition: A brain bruise caused by either a physical blow to the head or shaking the brain around in the skull (such occurs to a shaken baby or a soldier caught in the blast wave of an explosion), often resulting in a brief loss of consciousness and frequently resulting in a bad headache which may last for days. More serious bruising may require medical treatment to relieve pressure on the brain caused by excessive bleeding.
Typical Age of Symptom Onset: Any age, most common 0-4years and 15-24years, severe concussion more common over 65 years (more than twice as common in males)
Primary Symptoms: Brief loss of consciousness and/or seeing flashes of light or hearing a ringing noise (seeing stars or having your bell rung), followed by a gradually developing migraine-type headache that may be accompanied by nausea and/or vomiting. Some people with concussions may experience temporary loss of vision or blurred vision in one or both eyes or experience visual distortions such as zigzag lines.
Immediately after a concussion, mental processes are slowed and the individual may have difficulty answering simple questions or following instructions. Eye tracking of moving objects is measurably slower.
In general, the longer the individual is unconscious after an injury and the longer the period of mental confusion, the more severe the concussion. Differences between the sizes of the left and right pupils and/or erratic eye movements are also signs of a more severe concussion.
Secondary Symptoms: After experiencing a concussion, individuals are usually very sleepy and often sleep more than usual for the next several days.
Due to the slower mental processing and general fuzziness of thinking after a concussion, anyone who has experienced even a minor concussion is at increased risk of additional injury until they have fully recovered.
Some people develop post-concussion syndrome, with symptoms such as headache, difficulty concentrating, and/or depression lasting several weeks or months after a mild concussion. (See: Fact Sheet Post-Concussion Syndrome.)
More severe concussions may result in bleeding beneath the skull (subdural hematoma), which can lead to a coma if the pressure on the brain is not relieved.
Localized neuronal damage can result in epileptic seizures.
Some individuals will develop tinnitus (ringing or buzzing in the ears) after a concussion. The risk of developing tinnitus is greatly increased if the individual takes aspirin for the post-concussion headache. Other types of over-the-counter pain relievers do not appear to have this effect on development of tinnitus.
More severe concussion or repeated concussion without sufficient recovery time between injuries can result in a range of long-term cognitive or emotional symptoms such as emotional instability or difficulty in planning and organizing tasks. Depending on the precise size and shape of the injury, these post-concussion symptoms can be limited or could result in more general impairment. In addition, the symptoms of post-concussion syndrome may be mistaken for post-traumatic stress disorder (PTSD) because the symptoms of the two are often similar and because head injuries tend to occur under conditions such as traumatic accidents or violent assault that also produce a lot of stress.
Concussions tend to increase the risk that the individual will develop a neurodegenerative condition such as Alzheimer’s Disease or Parkinson’s Disease at a later point.
Cause(s)/Risk Factor(s): Impact to the head with a hard object or a blast wave from an explosion. The main symptoms of concussion result from the bruising of brain tissue that comes from the brain moving back and forth inside the skull. This movement damages small blood vessels (similar to a stroke) and causes swelling of the brain, which puts pressure on the meninges surrounding the brain and causes the headache.
Head trauma is most commonly associated with sports injuries or automobile accidents in teens and young adults. In children and the elderly, the most common cause is falls. Blast wave injuries are most commonly associated with military service.
Standard Treatment(s): For most minor concussions, rest is the only treatment required. After several days without further injury, the damaged blood vessels can generally repair themselves. Since the kind of diffuse injury that occurs after a mild concussion cannot generally be detected with standard imaging techniques such as MRIs or CAT scans, imaging may not be performed on individuals who have had a concussion but show only mild neurological symptoms. Even after a minor concussion, however, it’s generally advised that the injured person be monitored for at least several hours in case there is additional bleeding. A second loss of consciousness or the development of new visual symptoms or confusion may indicate that a subdural hematoma has developed.
If someone who has experienced a concussion begins to show poor coordination, increased mental confusion, and differences between the sizes of the left and right pupils, vomits persistently, has a seizure, or loses consciousness and cannot be woken up, they should be taken to the hospital right away.
Individuals who have suffered even a minor concussion are generally advised to avoid contact sports or other activities that might shake the brain or risk an additional injury for at least 2 to 3 days. More severe concussions require a longer period. Tasks that require mental focus, such as school homework, should also be delayed until the headache subsides. As with migraines, bright lights or loud noises may make the headache worse.
If the individual was unconscious for more than a few seconds or showed other signs of a more severe concussion, X-rays, CAT scans, or MRI images may be taken in order to evaluate subdural bleeding. If subdural bleeding is detected, a hole will typically be made in the skull to remove fluid and relieve pressure on the brain. (This is actually a simple and often extremely effective lifesaving and/or brain saving procedure.)
Non-aspirin pain relievers may be taken to treat post-concussion headaches. Aspirin is not advised as it increases the risk of developing tinnitus (ringing in the ears) after these types of injuries.
If emotional problems or difficulties with specific mental tasks develop as a result of the brain injury (post-concussion syndrome), cognitive behavioral therapy may be recommended to help the individual learn strategies for dealing with these problems.
For more information about evaluating concussions and aftercare of individuals who have had a concussion, see: http://www.cdc.gov/headsup/parents/index.html
For more information about the long term effects of concussion, see: Understanding Mild Traumatic Brain Injury and Fact Sheet Post-Concussion Syndrome.
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