A concussion is a traumatic injury to the brain caused by a sharp blow or sudden stop following an event. Ordinarily the brain floats inside the skull in a protective pool of spinal fluid, but certain actions like a hard tackle or a car accident can literally slam the entire brain against the skull's interior walls. The resulting damage can be mild to severe, depending on the intensity of the blow and the brain's ability to realign itself afterwards. Many people recover from a mild concussion within hours, but others may exhibit symptoms for weeks after the event.
A typical concussion scenario may play out during a sporting event such as football. A defensive player may make a hard tackle on the quarterback after a pass, and the quarterback will fall down to the ground. Meanwhile, the quarterback's brain tries to remain focused in one direction while his body is violently thrown in another. When the quarterback strikes the ground, his brain is jolted from the momentum.
For a few minutes, the stricken player may experience dizziness, loss of consciousness, weakness in one side of his body or an uneven dilation of pupils. He may feel nauseated or break into convulsions. This is a classic example of a concussion.
The effects of a mild to moderate concussion usually resolve themselves after a few hours of rest. There may still be some problems with vision or orientation, but the brain should eventually recover from the concussion over time. The most severe form of concussion, however, can be marked by an extended period of unconsciousness, mood swings, depression and bleeding inside the brain. This level of concussion can usually be diagnosed through the use of MRI or CT scans soon after the incident. Not all bleeding or bruising of the brain is considered dangerous or life-threatening, but a concussion can aggravate existing conditions not previously diagnosed.
Some people who suffer a concussion may experience a condition known as postconcussion syndrome. Even after a few weeks have past, those suffering from postconcussion syndrome may still experience weakness on one side of the body, extreme mood swings and/or problems with basic cognitive functions, such as memory or orientation. This is why many physicians recommend that friends and family observe anyone who has suffered a concussion in the past few months. Any significant changes in personality or cognitive ability should be noted for future reference.
A concussion is considered to be one of the mildest forms of brain injury, so most sufferers should recover fully and be able to resume their normal lifestyles. However, there are studies which suggest that a new concussion can aggravate an older concussion and cause even more complications.
The most common symptoms of concussion are:
headache
dizziness
nausea
loss of balance
confusion, such as being unaware of your surroundings
feeling stunned or dazed
disturbances with vision, such as double vision or seeing "stars" or flashing lights
difficulties with memory (see below)
Difficulties with memory can take one of two forms, or possibly both forms:
retrograde amnesia – where you are unable to remember events that occurred before the concussion happened. This usually only affects the minutes immediately leading up to the concussion.
anterograde amnesia – where you are unable to remember any new information or events after the concussion happened.
Both retrograde and anterograde amnesia usually improve over the space of a few hours.
Less common signs and symptoms of concussion include:
loss of consciousness
vomiting
slurred speech
"glassy eyes" and a vacant stare
changes in behaviour, such as feeling unusually irritable
inappropriate emotional responses, such as suddenly bursting into laughter or tears
The following signs and symptoms suggest it is likely that the head injury has caused serious damage and you should phone for an ambulance immediately:
remaining unconscious after the initial injury
difficulty staying awake or still being sleepy several hours after the injury
having a seizure or fit
difficulty speaking, such as slurred speech
prolonged vision problems, such as double vision
difficulty understanding what people say
reading or writing problems
balance problems or difficulty walking
loss of power in part of the body, such as weakness in an arm or leg
"pins and needles" in the hands or feet
amnesia (memory loss), such as not being able to remember what happened before or after the injury
clear fluid leaking from the nose or ears (this could be cerebrospinal fluid, which normally surrounds the brain)
a black eye, with no other damage around the eye
bleeding from one or both ears
sudden deafness in one or both ears
As a precaution it is recommended that you visit your nearest emergency department (A&E) if you or someone in your care has a head injury resulting in concussion and then develops any of the following signs and symptoms:
loss of consciousness from which the person then recovers
loss of memory of events that happened before or after the injury (or both)
persistent headaches since the injury
persistent vomiting since the injury
changes in behaviour, such as irritability, being easily distracted
confusion
drowsiness that goes on for longer than an hour when you would normally be awake
problems understanding or speaking
loss of balance or problems walking
weakness in any limb
clear fluid or blood coming out of the ear or nose
sudden deafness in one or both ears
There are also a number of factors that make you more vulnerable to the effects of a head injury:
being aged 65 or older
having a previous history of having brain surgery
having a condition that makes you bleed more easily, such as haemophilia, or having a condition that makes your blood more prone to clotting, such as thrombophilia
taking anticoagulant medication to prevent blood clots, such as warfarin or low-dose aspirin
It is also recommended that anyone who is drunk or high on recreational drugs is taken to A&E if they have a head injury resulting in concussion. It is often easy for others around them to miss signs and symptoms of a more severe injury.
Bleeding under the scalp, but outside the skull, creates a "goose egg" or large bruise (hematoma) at the site of the head injury. A hematoma is common and will go away on its own with time. The use of ice immediately after the trauma may help decrease its size.
Do not apply ice directly to the skin - use a washcloth as a barrier and wrap the ice in it. You may also use a bag of frozen vegetables wrapped in cloth, as this conforms nicely to the shape of the head.
Apply ice for 20-30 minutes at a time and repeat about every two to four hours. There is little benefit after 48 hours.
Rest is important to allow the brain to heal.
Bed rest, fluids, and a mild pain reliever such as acetaminophen (Tylenol) may be prescribed.
Ice may be applied to bumps to relieve pain and decrease swelling.
Cuts are numbed with medication such as lidocaine, by injection or topical application. The cut is then cleansed thoroughly with a saline solution and possibly an iodine solution. The doctor will explore the injury to look for foreign matter and hidden injuries. The wound usually is closed with skin staples, stitches (sutures), or, occasionally, a skin glue called cyanoacrylate (Dermabond).