Overview, Causes, & Risk Factors

A concussion is the most common form of headinjury. Most concussions are caused by a blow to the head or sudden, uncontrolled,rapid movement of the head. A concussion may cause temporary symptoms but notpermanent brain damage.

What are the causes and risks of the injury?

There are many possible causes for a concussion. Some common causes are bicycleaccidents, automobile accidents, falls, and work-related injuries. Contactsports, especially football, are another common source of concussions. Someother sports that place a person at risk for concussions include:

  • boxing
  • basketball
  • baseball
  • ice hockey
  • skiing
  • skateboarding
  • wrestling
  • almost any other contact sport
  • Concussions are more common in an individual who has:

  • an altered mental state due to drugs or disease
  • difficulty walking because of arthritis, leg injury, or neuromuscular disease
  • weakness
  • loss of balance or poor coordination from aging or disease
  • Symptoms & Signs

    What are the signs and symptoms of the injury?

    The American Academy of Neurology has recently established guidelines forsorting concussions into Grades 1, 2, and 3. Each grade has different symptoms,and treatment recommendations vary according to the grade.

    A person with a Grade 1 concussion does not lose consciousness.Symptoms of a Grade 1 concussion go away in less than 15 minutes, and mayinclude:

  • headache
  • dizziness
  • ringing in the ear
  • confusion
  • vision changes, including blurredvision
  • A person with a Grade 2 concussion does not lose consciousness, and hassymptoms similar to those of a Grade 1 concussion. However, the symptoms lastmore than 15 minutes.

    A person with a Grade 3 concussion does lose consciousness fora few seconds to many hours. When the person awakens, he or she may havemany of the symptoms of a Grade 1 concussion, as well as:

  • loss of awareness
  • memory loss regarding the eventssurrounding the injury, also known as amnesia
  • seizures
  • vomiting
  • difficulty walking
  • weakness
  • an altered level of consciousness. The person may be difficult to awakenor may not be acting normally.
  • Diagnosis & Tests

    How is the injury recognized?

    A concussion can be diagnosed by a healthcare professional with a standardneurological exam and complete history. An EEG, or electroencephalogram, may be ordered to check for abnormalitiesin the brain waves.

    Tests such as a cranial CT scan, X-ray, and cranial MRI may also be used to determine the amount of damage tothe brain. Often, all tests will be normal because the injury is not severeenough to detect.

    Prevention & Expectations

    What can be done to prevent the injury?

    Sports safety guidelines should be followed for children, adolescents,and adults. Helmets and seat belts areespecially important in the prevention of head injuries leading to concussions.

    Treatment & Monitoring

    What are the treatments for the injury?

    A person with a Grade 1 concussion should be checked at the time of the head injury, and then every 5 minutes untilthe symptoms go away. If the symptoms disappear in 15 minutes or less, the personcan return to normal activity, including sports.

    A person with a Grade 2 concussion should be examined by a healthcare providerand should avoid sports for a week.

    When a person loses consciousness for any length of time following aconcussion, he or she has a Grade 3 concussion. The individual should beimmediately transported with a neck brace to a hospital for treatment.

    What are the side effects of the treatments?

    Most people fully recover from concussions without side effects.

    What happens after treatment for the injury?

    A person with a Grade 1 concussion can return to normal activity, includingsports, when the symptoms go away. An individual with a Grade 2 concussionshould refrain from sports for one week. If the person is still symptom freeafter one week, he or she may return to sports activities.

    A person with a Grade 3 concussion should follow the recommendations of thehealthcare professional regarding activity. The person’s return to sports willdepend on how long he or she was unconscious, and how long it took for thesymptoms to go away. An individual with repeated concussions should becarefully evaluated before returning to sports activities.

    Any new or worsening symptoms should be reported to the healthcare provider.

    Article type: xmedgeneral