Reviewed on 8/19/2022

What Facts Should I Know About Concussion?

Concussions, or traumatic brain injuries, can be mild or severe.
Concussions, or traumatic brain injuries, can be mild or severe.

What is the medical definition of concussion?

The term concussion describes an injury to the brain resulting from impact to the head. By definition, a concussion is not a life-threatening injury, but it can cause both short-term and long-term problems. A concussion results from a closed-head type of injury and does not include injuries in which there is bleeding under the skull or into the brain. Another type of brain injury must be present if bleeding is visible on a CT scan (CAT scan) of the brain.

How serious is a mild concussion?

  • Mild concussion: May involve no loss of consciousness (feeling "dazed") or a very brief loss of consciousness (being "knocked out").
  • Severe concussion: May involve prolonged loss of consciousness with a delayed return to normal.

What Causes a Concussion?

A concussion can be caused by any significant blunt force trauma to the head such as:

  • Falls
  • Car accidents
  • Sports injuries
  • Being struck on the head with an object

What Are the Symptoms and Signs of a Concussion?

Common signs and symptoms of concussion include:

  • Loss of consciousness after any trauma to the head
  • Confusion
  • Headache
  • Nausea or vomiting
  • Blurred vision
  • Loss of short-term memory (you may not remember the actual injury and the events some time before or after the impact)
  • Perseverating (repeating the same thing over and over, despite being told the answer each time, for example, "Was I in an accident?")

When to Seek Medical Care for Concussion

Call a doctor about any of the following situations. The doctor will recommend home care, set up an appointment to see the affected individual or send the person to the emergency department.

  • Injury occurred due to being struck with a hard object with the head (for example, tile floor, ice, bathtub)
  • Mild dizziness or nausea after a head injury
  • Loss of memory of the event (amnesia) for just a few minutes
  • Mild headache with no vision disturbances

Go to an emergency department by ambulance in the following situations. For people with less severe injuries not requiring ambulance transport, a car may be taken to the hospital.

  • Severe head trauma, for example, a fall from more than the height of the person or a hard fall onto a hard surface or object with resulting bleeding or laceration.
  • Any child that loses consciousness as the result of a head injury.
  • Prolonged loss of consciousness (longer than two minutes)
  • Any delayed loss of consciousness (for example, the injured person is knocked out only momentarily, then is awake and talking, then loses consciousness again)
  • Vomiting more than once
  • Confusion that does not go away quickly
  • Restlessness or agitation
  • Extreme drowsiness, weakness, or inability to walk
  • Severe headache
  • Loss of memory of the event (amnesia)
  • Perseverating (saying the same thing over and over)
  • Seizures or convulsions
  • Slurred speech
  • Someone who takes warfarin (Coumadin) or platelet inhibitors clopidogrel (Plavix) and aspirin (Aggrenox) for a medical problem and suffers a significant blow to the head.
  • If the person fails to regain consciousness after two minutes, however, or the injury is very severe even if two minutes have not passed, DO NOT move the person. Prevent movement of the neck, which may exacerbate spinal injuries. If the person needs to vomit, carefully roll the person onto his or her side without turning their head. Call 911 immediately for help.

If you are unsure of the severity of the injury, take the person to the emergency department immediately.

Should an injured person be allowed to fall asleep? Many mistakenly believe it is important to keep people, especially children, awake after they have been struck on the head. Children are often more emotionally upset than they are physically injured after a minor fall. They will cry and appear distressed, but as the parent rushes them to the hospital, children may begin to calm down. Because they have expended a lot of physical and emotional energy crying, they will often want to go to sleep.

  • You do not need to keep the patient awake. In many cases, it may be helpful to the emergency doctor to be able to awaken the person who is now calmer and rested and will behave normally. This gives the doctor a better assessment of the severity of the head injury.
  • If, however, a person who was initially normal after a head injury cannot be awakened or is extremely difficult to awaken, then the person may have a more serious head injury and should be evaluated by a doctor.

How Can You Tell if You Have a Concussion?

The doctor will make sure that there are no severe or life-threatening injuries first and then will further evaluate the severity of the head injury.

History of the injury

If you can, give the doctor the following details about the injury:

  • How long the person was unconscious
  • Details about how the injury happened, such as the speed of travel in a car accident, the height of a fall, or the size of the person or object that hit the victim.

Past medical history

Tell the doctor about the history of any of the following:

  • Current medications, especially warfarin (Coumadin) or platelet inhibitors clopidogrel (Plavix) and aspirin and dipyridamole (Aggrenox)
  • Allergies to medications
  • Prior head injury or concussion, neurologic injury, or surgeries
  • Bleeding disorder or history of easy bleeding or bruising

Physical examination

During the physical examination, the doctor will:

  • Assess normal neurologic functions such as reflexes and mental status.
  • Examine the patient for other associated injuries, such as a neck injury or whiplash, that are common with a head injury.
  • Inspect for bleeding from the ears or nose as well as bruising around the eyes or behind the ears that are commonly seen with certain types of fractures to the base of the skull.

Many times people are concerned about a cut (laceration) on the scalp or face, and the doctor may not seem to take much notice. These cuts may bleed and appear serious, but severe or life-threatening bleeding from such a cut is rare and would be recognized right away. The doctor's main concern will be to assure that there is no serious brain damage, or neck or torso injury. The cut can be repaired later.

CT scans

The best way to evaluate a person's head injury is with a CT scan. This machine takes cross-sectional X-rays of the head (or other body parts), and a computer reassembles the information into images to let the doctor see details of the inside of the body. When a CT scan is used for a head injury, the doctor will look for evidence of bleeding under the skull or within the brain tissue itself.

  • With less serious head trauma, the doctor may choose not to do a CT scan. A minor concussion can safely be observed either at home or in the hospital for 24-48 hours. If no other serious signs of injury develop, the person will usually be safe.
  • Skull X-rays are no longer routinely used to evaluate a person with a concussion.
  • A concussion may be accompanied by a skull fracture. The patient may still have a skull fracture even though the doctor does not perform a CT scan or take X-rays. This is acceptable. The presence of a fracture does not, alone, increase the likelihood of an injury to the brain unless there are also other signs of head injury.
    • Skull fractures almost always heal well. Casts are not used on the head.
    • In rare cases, a leptomeningeal cyst may form. These are bulges of the bone and tissue at the site of the fracture, which develop months later. There is no way to predict their occurrence or to prevent them.
    • If the patient notices a bump forming months after a head injury, see a doctor. X-rays of the skull may be done at that time, and if there is a leptomeningeal cyst forming, the patient will be referred to a neurosurgeon for evaluation and treatment.

In the past, concussions were commonly graded on a scale according to severity. Most commonly, concussions are referred to as symptomatic or asymptomatic (meaning that symptoms are or are not present, respectively). Neurologists may do further testing to grade a concussion's severity.

What Is Self-Care at Home for a Concussion?

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.

In 2010, the American Academy of Neurology called for any athlete suspected of having a concussion to be removed from play until the athlete is evaluated by a physician. If a concussion is suspected due to a sports injury, the Centers for Disease Control recommends implementing a 4-step plan:

  1. Remove the athlete from play.
  2. Ensure that the athlete is evaluated by a health care professional experienced in evaluating for concussion. Do not try to judge the severity of the injury yourself.
  3. Inform the athlete's parents or guardians about the possible concussion and give them the fact sheet on concussion.
  4. Keep the athlete out of play the day of the injury and until a health care professional, experienced in evaluating for concussion, says they are symptom-free and it's OK to return to play.

A repeat concussion that occurs before the brain recovers from the first—usually within a short period of time (hours, days, or weeks)—can slow recovery or increase the likelihood of having long-term problems. In rare cases, repeat concussions can result in edema (brain swelling), permanent brain damage, and even death.

What Is the Treatment for a Concussion?

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).

What Is the Follow-up for a Concussion?

After initial treatment, the patient will be referred for follow-up care to their primary care doctor or a specialist, such as a neurologist. It is important to keep these appointments, particularly because some of the more subtle problems of concussion (memory deficits, personality changes, and changes in cognition) may not be apparent at the time of the initial injury.

Can You Prevent a Concussion?

The use of protective headgear can decrease the risk of concussion when engaging in any of the following activities:

  • Contact martial arts sports such as boxing, karate, and others
  • Football
  • Hockey
  • Rollerblading
  • Cycling (bicycles and motorized)
  • Baseball
  • Skateboarding

Always use seatbelts in automobiles.

"Fall proof" your home and your surroundings with the following measures:

  • Make sure your living space is uncluttered.
  • Make sure furniture is secure and in good repair.
  • Ensure rugs or carpets are safe to walk on and do not slip or slide on the floor.
  • Clean up spills on slippery surfaces immediately and thoroughly.
  • Install window guards and safety gates to prevent falls leading to concussion in children.

What Is the Prognosis for a Concussion?

A person with a single, isolated concussion generally has a very good recovery outcome with few long-term effects.

Short-term effects

  • The main symptom of postconcussive syndrome is persistent headache for 1-2 weeks, lasting up to months after the injury.
  • Sometimes people with postconcussive syndrome will have dizziness, difficulty concentrating, difficulty sleeping, or problems doing certain types of activities such as reading.
  • Nausea and vomiting may occur.
  • Affected individuals may also experience other subtle cognitive or emotional problems.
  • Affected individuals can develop at least one symptom of postconcussive syndrome within the first month following injury, and some have at least three symptoms by three months post-injury.
  • Postconcussive syndrome is more common after a serious concussion than after a mild one.
  • Symptoms usually are relieved with mild pain relievers such as acetaminophen (Tylenol) or ibuprofen (Motrin, Advil).
  • Postconcussive syndrome usually goes away on its own with time. Some people may have symptoms that do not go away, even after months. In this situation, contact a doctor. Sometimes tests (such as an MRI or cognitive function testing) or consultations with a neurologist can better assess this problem.

Long-term effects

  • Concussions are known to be cumulative. That is, each time you have a concussion it is easier to get another concussion in the future.
  • Repeated concussions can lead to long-term memory loss, psychiatric disorders, brain damage, and other neurologic problems.
  • If a person has had a number of concussions, the doctor likely will advise the person to avoid the activities that may put them at risk for future head injuries and to discontinue contact sports. Professional athletes are particularly prone to the effects of cumulative concussions.

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