Brain Injury in Combat Sports

Headguards for boxers were first introduced in 1984 at the Los Angeles Olympic Games as a safety measure to protect the athletes’ health. In 2013, protective headgear for male elite boxers was prohibited based on arguments that using headguards provided boxers with a false sense of security, causing them to take more risks in the ring and sustain more head injuries (AIBA, 2015). However, women, youth and junior boxers are still required to wear headguards, with little rationale provided for this distinction in rulings from the men’s competition.

This has fuelled a debate on the pros and cons of protective headgear in boxing and wider combat sports. Some of the common arguments for keeping headguards are that it provides better protection to the head from gloves/feet, and reduces cuts to the side of the face and ears. On the opposing side, there are arguments that using headgear increases risk-taking behaviour and gives a false perception of safety, increases the target area for opponents, and decreases peripheral vision of the wearer.

The most accepted opinion is that current and conventional combat sport and boxing headgear provides no protection beyond cuts and scrapes, but they were never designed to do so!

In every impact to the head in combat sports there are rotational forces present, and these cause the brain to rotate inside the skull. This is associated with the tearing of tiny blood vessels and brain cells, resulting over time in the break-down in the blood-brain barrier and the creation of damaging neuro-inflammation. Reducing rotational forces to the brain is essential to lower the risk of neuro-inflammation in combat sports.

Rezon offers brain protection in combat sports. Halos®, created by Rezon, is a protective headband for use in combat sports that reduces rotational forces by up to 61%. The design of Halos® reduces rotational forces i.e., the more dangerous forces to the brain through a nine-layered technology that reduces the transmission, or passing through, of rotational forces to the brain. It covers the areas of highest rotational injury risk, such as the back and sides of the head. Direct head impacts in striking sports produce greater rotational forces than impacts from throws or takedowns in grappling sports, and appear to put combat sports athletes at greater risk of TBI ^[1]. There is a well held belief and perception in boxing that an impact to the jaw causes maximum damage to the brain, but the highest rotational forces are recorded in front impacts ^[1].

Concussion

Concussion, also known as “mild” Traumatic Brain Injury (mTBI), is caused by a single impact to the head or body and temporarily impairs brain function. This impact creates abnormally strong rotational forces to the brain, causing damage to brain nerve cells and the shearing of brain cells.

Concussion produces symptoms that an individual is aware of or another person can see.  Combat sports players should be removed as soon as they are suspected of having a concussion and not return.

Symptoms of concussion can be both physical and cognitive, and with changes in sleep and emotions.

Loss of consciousness (being knocked out) occurs in less than 10% of concussions. It is not required to diagnose a concussion.

A concussion can last from hours to days, and depends on each individual case. Initially, there is a need for 24-48 hours of rest, followed by a gradual resumption of everyday activity, and then a graduated return to cognitive and physical activity.

Changes in white matter, brain connections and blood flow can persist a year or more after a concussion. Returning to combat sports too early can increase the risk of sustaining further injury and subsequent symptoms, requiring a prolonged period of recovery.

Post-concussion syndrome (PCS) can occur after sustaining a concussion.

Symptoms may persist for weeks and include:

• Headaches
• Dizziness or balance problems
• Fatigue and insomnia
• Memory problems or difficulty concentrating
• Irritability, anxiety, or depression
• Sensitivity to light and sound

Up to 1 in 3 individuals will develop Persistent Post-Concussion Symptoms (PPCS) meaning an extended recovery time with cognitive, behavioural and emotional difficulties. This can last for months to years. PPCS symptoms vary by individual, though common symptoms include:

• Headaches
• Fatigue
• Dizziness
• Cognitive difficulties
• Emotional changes

These symptoms can significantly impact everyday life and individuals with PPCS are at greater risk of experiencing depressive symptoms. The most common PPCS outcomes measured for sports concussion were depression and cognitive functioning (e.g. memory, poor concentration, slower processing, frustration, irritability) ^[2].

Females experience more significant post-concussion issues and a longer period of recovery post-concussion. Post-concussion anxiety and depression are widely recognised as more prevalent in females than males by 2:1 ^[3].

SIS

There are serious risks in returning to play too soon after a concussion, including where another impact has the potential to be fatal – Second Impact Syndrome (SIS).

SIS is a very serious risk when a combat sports player suffers a further concussive head injury before they have made a complete recovery from an initial concussion. This causes the brain to swell rapidly and catastrophically. The second injury may occur minutes, days, or weeks after an initial concussion and even the mildest impact can lead to SIS. This is often fatal and almost everyone who is not killed is severely disabled. This condition primarily occurs in school-age children.

Sub-concussions and CTE

There is a significant lack of awareness across participants and trainers of possibly the greatest threat to the brain in combat sports: sub-concussions. Sub-concussion results from an impact of lower force than required to cause a concussion. Sub-concussive impacts are 500 times more frequent than impacts which result in concussion. A sub-concussion causes damage to the brain without any symptoms.

While not every combat sports player will suffer a concussion, they will typically take hundreds, and likely thousands of sub-concussions.

The rotational forces present in sub-concussive impacts rotate the brain inside the skull, tearing tiny blood vessels and brain cells. This creates inflammation and the production of neurochemicals in the brain, which results in damage to the blood-brain barrier – a structure designed to protect the brain.

When the brain is subjected to repetitive and frequent sub-concussions in combat sports, the responses from the earlier sub-concussion haven’t yet returned to normal levels. Consequently, subsequent sub-concussive injuries can cause an exaggerated production of neurochemicals and an exaggerated inflammatory response. This becomes harmful to the brain, rather than protective. It damages brain tissue and leads to the irreversible death of brain cells. Over time, this leads to changes in a brain protein called tau and increases the risk of Chronic Traumatic Encephalopathy (CTE). This is a progressive neurodegenerative disease that leads to early-onset dementia in a person’s 20s/30s/40s.

CTE symptoms include:

• Memory problems;
• A decline in thinking ability;
• Confusion;
• Aggression;
• Depression; and
• Changes in personality.

It is debilitating and life-changing for those affected and their families and friends.

Between ages 8-12 is when peak development of the brain occurs, but the brain continues to develop through the refinement and rearrangement of brain pathways and connections until early 20s.

Axons are the tail-like structures that connect neurons in the brain and connect neurons to other cell types. Axons are coated in myelin, and this improves how electrical discharges transfer information along the axon – and is crucial to healthy brain function. Myelin is formed as the brain develops, beginning a few months after birth and continuing until the mid-20s.

Children and youths have less myelin than adults, and this is problematic because myelin protects the axon. Axons with little myelin are more exposed and prone to damage from concussions and sub-concussions. Less myelinated axons also don’t recover as well from injury as highly myelinated axons.

This means younger combat sports participants are more vulnerable to brain injury, and their brains will undergo noticeable changes as a result of head to hand, foot, floor, or head impacts, even if they were never diagnosed with a concussion.

Increased research and dialogue around CTE risk has heightened the expectations on those with a legal duty of care. This extends to coaches, trainers, clubs and gyms to take greater steps to preserve brain health and reduce the risk of repeated brain injury in combat sports.

Currently, the focus in combat sports is on management of concussion, and not on sub-concussions and their long-term damage to participants. But as we are seeing in the UK with over 1,000 former rugby and football (soccer) players diagnosed with early-onset dementia and CTE taking the sport’s governing bodies to court over failure to protect them from the risk of brain trauma, there is now heightened expectations on those with a legal duty of care to take greater steps to preserve brain health and reduce the risk of repeated brain injury.