The ImPACT Test 

ImPACT's Test is computerized and takes about 25 minutes to complete. ImPACT recommends that it be administered by an ImPACT trained athletic trainer, school nurse, athletic director, team doctor or psychologist. Baseline tests are suggested every two years. If a concussion is suspected, the baseline report will serve as a comparison to a repeat ImPACT test, which professionals can use to assess potential changes or damage caused by a concussion. The management of concussions should only be conducted by trained medical professionals. To achieve this, ImPACT is expanding reach to manage concussions through a growing national network of several hundred clinical professionals who are Credentialed ImPACT Consultants™ (CICs).

IMPACT Features
Measures player symptoms
Measures verbal and visual memory, processing speed, and reaction time
Reaction time measured to a 1/100th of second
Assists clinicians and athletic trainers in making difficult return-to-play decisions
Provides reliable baseline test information
Produces a comprehensive report of test results
Results are presented as a PDF file and can be emailed
Automatically stores data from repeat testing
Testing is administered online for individuals or groups
Compatible with PC and MAC

The test modules consist of a near infinite number of alternate forms by randomly varying the stimulus array for each administration. This feature was built in to the ImPACT Test to minimize the "practice effects" that have limited the usefulness of more traditional neurocognitive tests.

The program measures multiple aspects of cognitive functioning in athletes, including:
Attention span
Working memory
Sustained and selective attention time
Response variability
Non-verbal problem solving
Reaction time

Concussion Definition:
Concussions are a type of brain injury and are sometimes referred to as a Mild Traumatic Brain Injury (mTBI). A concussion is caused by the head moving rapidly back and forth. This may be from a direct blow to the head, face, or neck or by a blow to the body with a resultant movement of the head.

Concussions result in immediate symptoms that typically resolve spontaneously over a short period of time. These symptoms are not due to a structural change in the brain which is why there are no changes typically found on scans of the head. An athlete does not need loss of consciousness to have a concussion.

Signs and Symptoms:

The public has become increasingly more aware of the dangers of concussions as the media has focused more attention to the topic. Athletic trainers, athletes, and coaches have also become more adept at recognizing the signs and symptoms associated with concussions. The signs and symptoms of concussion typically resolve in 7 to 10 days. There are some recoveries from concussions, however, that may take weeks to months.

Some typical symptoms associated with concussion include:

Physical: Headache, nausea, vomiting, balance problems, visual problems, fatigue, sensitivity to light or noise, dazed, stunned.
Cognitive (thinking): Feeling mentally “foggy” or slowed down, difficulty concentrating or remembering, forgetful of recent information, confused about recent events, answers questions slowly, repeats questions.
Emotional: Irritable, sad, more emotional than normal, nervous.
Sleep: Drowsiness, sleeping more or less than usual, difficulty falling asleep.

What to Do for Suspected Concussion?
The CDC has a four step process for a suspected concussion.

Remove the athlete from play.
Ensure the athlete is evaluated by a healthcare
professional experienced in evaluating concussions.
Inform the athlete’s parents or guardian about the possible concussion and give them a fact sheet on concussion.
Keep the athlete out of play the day of injury and until a health professional, experienced in evaluating concussions, says they are symptom-free and okay to return to play.

Source: The CDC