Brain Concussion

Brain Concussion

Mitsutoshi Hayashi

Mitsutoshi Hayashi

Doctor of Medicine, specialist in the Japanese Society of Rehabilitation Medicine, specialist in the Japanese Society of Orthopaedic Surgery, specialist in the Japanese Society of Rheumatology, staff to strengthen JOC, and sports physician certified by the Japan Sports Association

Brain concussion

Concussion is a sports disorder that occurs particularly in contact sports.


Concussion is a temporary disturbance of consciousness or memory resulting from an external impact on the head (disturbance of consciousness does not necessarily mean loss of consciousness or altered consciousness). This disorder is reversible, and essentially no organic damage to the brain itself occurs. The following definitions of concussion are provided in the Safety Measures Manual of the Japan Rugby Football Union.
[Any obvious head bruise on the ground, abnormal response (state of consciousness) or any abnormality in physical activity at the time of injury falls under concussion as a rule of competition.]

Most common events

Contact sports, such as American football, rugby, boxing, ice hockey, motor biking, gymnastics, horse riding, and skiing, and sports where the head may be injured in falls are most common.


Even though the patient is conscious, headache, dizziness, tinnitus, nausea, and blurred vision may occur. More severe symptoms may be associated with memory loss (names, date of birth, address, time of injury, and subsequent questions about what to say), inability to speak, and breathing and heart rhythm irregularities. If the person has headache with disturbance of consciousness within 5 minutes, it would be severe case and evaluation by a doctor is essential. If consciousness is severely affected for more than 5 minutes, the patient should be immediately transported to the hospital. It is also important to remember that head injuries are likely to be complicated by cervical spine sprains and whiplash symptoms (neck pain and stiff shoulders).

Concussion 2

Follow the ball behind, and immediately after catching it, the player crashed hard into the advertising fence from the back of the head. He was able to continue, even though he fell down.

First aid

After a concussion, the person must rest, and the level of consciousness, breathing, and pulse need to be checked. Then, make sure to conduct icing on the head and neck region, and check if there is paralysis of the hand and the leg even if the person isn’t unconscious. Do not give water to athletes with impaired consciousness, because they may choke after throwing up.

Return to sports

In the actual sports field, cases of mild symptoms, rather than head bruises with clear consciousness disturbance, may become problems as these would lead to make judgment of return immediately. The judgment can be made differently by the presence or absence of consciousness. The athlete can return to competition if there is no loss of consciousness (-), loss of memory (-), headache, nausea, or dizziness, and there is no imbalance in jumping or dashing. However, a person with headache, facial pallor, or agitation should be monitored without returning to competition.

Severity classification of brain concussion and index of return to sports

1. (Mild): Loss of consciousness (-), traumatic amnesia within 30 minutes → no symptom persists for a week, return to sports is allowed.
2. (Moderate): Loss of consciousness within 5 minutes and traumatic amnesia within 30 minutes → no symptom persists for a week, return to sports is allowed.
3. (Severe): Disturbance of consciousness persists more than 5 minutes and traumatic amnesia persists for 24 hours → return to competition takes at least a month.

Typical case

This is a case of a 24-year-old male volleyball athlete during the international match.
He hit a relatively soft fence when was following the ball at 7:30 p.m. and he was able to continue playing without head bruising or disturbance of consciousness.
The game ended at 8:30 p.m. He continued having a headache and a feeling of discomfort after he returned to the lodgment and had dinner. He experienced sudden large-volume vomiting and a condition of stupor even though he was able to answer and open the eye (Figure, JCSI-2) around 10:30 p.m. He was taken to the hospital by ambulance and was admitted to the hospital for a follow-up. On the following day, he had a headache and neck pain even though he was awake and able to have breakfast. There was no evidence of a fracture by skull radiography. There were no obvious brain damage, bleed, or edema by CT or MRI. He was able to return to sports three days later by permission of a neurosurgical specialist, but he was eventually not able to perform satisfactorily as the headache and neck pain strongly persisted and he felt his body floated. In this case, it was difficult to determine when to return to sports after the head injury.


A study from the University of Toronto in 2004 reported negative mood disorders, such as depression and confusion, after a concussion due to a sports injury. Concussion-induced depression resolved within 7 days, confusion, and general mood disturbance resolved within 3 weeks, but emotional differences with teammates also occurred.

Classification of the degree of consciousness disorder according to the Japan Coma Scale (JCS) is divided into three grades.

1) Awake state without stimulus (expressed by one-digit) (delirium, confusion, and senselessness)

1. Awareness is lucid, but it is not quite clear at this time .
2. He/she has disorientation.
3. He/she cannot say name or date of birth.

2) Awake state when stimulated, falling asleep when stopping stimulating (expressed by two-digit) (stupor, lethargy, hypersomnia, somnolence, and drowsiness)

10. He/she can open the eye when being normally called. He/she can make purposeful movements (e.g., gripping or leaving the right hand). He/she can speak but there are some mistakes.
20. He/she can respond to a simple command to open the eye by a loud voice or shaking body, e.g., handgrip.
30. He/she can barely open the eye when adding painful stimulus and repetitive calling.

3) Not awake state when stimulated (expressed by three-digit) (deep coma, coma, and semicoma)

100. He/she tries to wave off toward painful stimuli.
200. He/she moves hands or feet slightly or frowns up his/her face toward painful stimuli.
300. He/she does not respond to painful stimuli

Yasuhiro Nakajima

Yasuhiro Nakajima

Head coach of Shonan Bellmares Sports Club Triathlon Team, Head coach of Triathlon Team of Nippon Sport Science University, and Chairman of the Japan Triathlon Union Multi-sports Committee

Trainer’s Edition


[Preventing Accidents] Although most head injuries occur accidentally, accidents must be prevented as much as possible. For this purpose, preventive measures must be taken in consideration of the characteristics of each competition, based on the following items. Not only does the instructor pay attention, but the player needs to be aware of the need to prevent it, so it is also necessary to have an opportunity for careful checks at meetings.
In the past, when I worked with an athlete to train on my bicycle, I fell and had a strong bruise on my head. However, because a helmet was worn, the helmet broke and absorbed the impact, which was not serious. Daily checks are important for athletes who use helmets or other protective equipment each time, because they may be inappropriately fitted due to habituation.


1. Use of improper helmets, etc. and not used in competition where helmet should be used:
Even in a competition in which the wearing of the helmet is obligatory during competition, it is not used during training, etc. The risk appears to be the same in competition and in training.
2. Inability to concentrate (feeling sick or relaxed):
Lack of concentration increases the likelihood of bruising the head without being able to respond to falls or contact with the other person, which can usually be addressed.
3. Use of a mouthpiece:
The use of a mouthpiece is known to prevent concussion. Use as much as possible in a competition in which it can be used.
4. Excessive strain:
The risk is increased when normal movements are prevented by excessive tension.
5. Technical immaturity:
Avoid unreasonable challenges and learn gradual skills. Prepare mats, auxiliaries, etc.
6. Large differences in physical fitness and skills between fighters:
Especially in contact sports, there is a high possibility of bruising the head when the tackle is done with a force that cannot be covered by the athletic skills.
7. Head-up and contact:
When playing rugby or American football, raise the head and avoid hitting your head as much as possible.
8. Strengthening of the neck

On-site evaluation and first aid

On-site measures

In American football, which is a representative contact sport, there are many injuries to the head, so there are detailed guidelines on how to deal with concussions in sports settings (Figure). It is important to consider how to deal with on-site accidents in advance based on these findings. There are some expressions that you don’t have to take to a medical agency depending on classification. However, if a person is somewhat anxious, a doctor's examination is recommended.

Symptoms of brain concussion

1. He/she has headache, nausea, and vomiting
2. He/she has difficulty to focus the eyes, hardly keeps eyes open in the glare and produces double vision.
3. He/she has tinnitus and not able to withstand loud sounds
4. He/she delays in speech and motor responses: delay in answering to questions and following the instructions.
5. He/she presents in a confused state and loss of concentration: an empty gaze and impaired attention.
6. He/she produces indistinct speech: unable to speak fluently or brings out incomprehensible words.
7. He/she has dyssynergia: totters along or unable to walk straight.
8. He/she has disorder of memory: asks the same questions many times.
9. He/she has disorientation: walks to a different direction or not able to answer time, date and place.
10. He/she lacks of strength in the hands and feet.

Assessment method

▼ Mental Status Testing
 Orientation: Saying the place, time, person, situation
 Concentration: Saying the figures back, etc.
 Memory: Asking about former opponents, etc.
▼ Nerve test
 Pupils: size, symmetry, and light reflexes
 Coordination: Finger-nose test (alternately touch the person's nose and examiner's fingers)
▼ Exercise testing
 Walk, run
 Such as push-ups and abdominal muscle exercises

Cerebral concussion

1. When a doctor is present, follow the advice. This should be regarded as a "guide in the absence of a doctor."
2. If you have any areas of concern, seek medical attention.

Figure: How to cope with brain concussion (Created by the 1998 American Football Medical Scientific Committee )

“Sports Traumatology II: Head, Neck, and Trunk ”, Ishiyaku Puclishers, Inc.


To avoid a second impact, some sports prohibit the athletes from training for 2 to 4 weeks , even if they do not have symptoms.
In addition, it is recommended that the person be conditioned on a step-by-step basis in the same way as other injuries until the person returns to competition.

Six steps are used to increase the level of exercise gradually after the symptoms have completely disappeared, as described below.

1. Inactivity (complete rest of body and cognitive function)
2. Perform mild aerobic exercise (e.g. walking or bicycle ergometer)
3. Perform sports-related exercise (e.g. no impact or rotation on the head such as running)
4. Movement and training without contact play
5. Perform training including contact play after receiving medical checkup
6. Return to competition

Above steps are cited from “Algorithm for graduated return to competition” (Nagashiro Shinji, et al.) (Neurotraumatology 2013)
If symptoms do not appear, you will proceed to the next stage, but it is recommended that you have a 24-hour interval between each stage and receive a medical check before eventually returning to play.