The stunned brain: neuroanatomical correlates of an acute concussion in boxing


                                                              The stunned brain: neuroanatomical correlates of an acute concussion in boxing

Nitin K Sethi, MD

Department of Neurology, New York-Presbyterian Hospital, Weill Cornell Medical Center, New York, NY (U.S.A.)










A concussion can be defined as a transient alteration of mental status due to biomechanical forces affecting the brain. Concussions are common in contact sports like boxing and mixed martial arts (MMA). In boxing frequently the goal is to win by causing a knockout (KO)/concussion though a fight may also be won by a body shot if the boxer is unable to continue. This is then ruled a technical knockout (TKO). In the case report that follows, the clinical semiology of an acute concussion in boxing is described and a speculative hypothesis about the neuroanatomical correlate of the syndrome is postulated.





Case Report


A-32-year old right handed professional male boxer with a record of 20 wins, no losses with 10 of the wins coming by way of knockout suffered a brutal KO during a high profile televised bout. The boxer went down with the head striking and then bouncing off the ring canvas. Immediately on impact with the ring canvas the boxer exhibited decerebrate posturing followed by a 20 second convulsion characterized by stiffening of the arms and low amplitude clonic jerks of the legs. The referee immediately signaled an end to the fight and motioned the ringside physician to enter the ring to tend to the downed fighter. Examination inside the ring revealed a conscious boxer (eyes open) with unresponsiveness (no response to commands). This conscious unresponsiveness state lasted for about one minute. Pupils were midsize, equal in size with sluggish response to light. The emergency medical service (EMS) personnel stationed ringside were summoned into the ring by the ringside physician. While maintaining spinal fixation, the boxer was placed in a hard cervical collar and lifted on to and strapped on a hard backboard. As this was been accomplished, the boxer suddenly became responsive and started punching the air with his gloved hands as if he was back in the midst of the bout. He was combative and attempting to get up from the board. He was restrained by the medical staff. After about 1 minute, he calmed down and became fully alert and oriented. He realized that the fight had been stopped because of a KO and requested the medical staff to allow him to get up. At the post-fight medical evaluation he was determined to have suffered an acute concussion and administered a 90 day medical suspension. A neurology clearance was also requested prior to return to competitive boxing.






The 5th international conference on concussion in sport held in Berlin, October 2016 defined a sport related concussion (SRC) as a traumatic brain injury induced by biomechanical forces resulting in the rapid onset of short-lived impairment of neurological function that resolves spontaneously 1. However, in some cases, signs and symptoms may evolve over a number of minutes to hours. While SRC may result in neuropathological changes, the acute clinical signs and symptoms largely reflect a functional brain disturbance rather than a structural injury with no abnormality seen on standard structural neuroimaging studies such as CT or MRI.


The centripetal theory of cerebral concussion postulates that in a concussion there is a centripetal progression of strains from the outer surfaces to the core (midbrain and basal diencephalon) of the brain 2, 3, 4. The anatomical localization of memory is in the temporal lobes or orbitotemporal regions. As per the centripetal theory, less degree of force does not penetrate deep into the cortex and so while cognitive and memory dysfunction may result, consciousness is retained. Forces strong enough to penetrate through to the mesencephalic brainstem result in loss of consciousness. It is important to remember that the above theory and biomechanical concepts are largely based on primate research and not on humans. The observation that brainstem signs can occur in the absence of significant “cortical” symptomatology and that cortical signs can occur in the absence of significant “brainstem” symptomatology means that the centripetal theory explains some but not all of the varied clinical semiology of concussion. It is generally accepted that traumatic decerebration, short duration traumatic coma (loss of consciousness) and impact seizure are brainstem release phenomena in which cortical inhibition of normally suppressed brainstem activity is lost due to diffuse cerebral injury. It may also be that the above phenomena are primarily due to failure of activity in the mesencephalic reticular formation and with loss of brainstem reflex response without widespread cortical involvement.  The amnestic symptoms noted during a concussion have been postulated to be due to a transient interruption or disturbance in the ascending cortical projections at the level of the mesencephalon. It is hence intriguing to think of a “brainstem concussion” distinct from a “cortical concussion” each with different clinical semiology and symptom complex 4.


The above described clinical semiology of an acute concussion in boxing has not been described thus far in the medical literature. While this “stunned brain syndrome” is unnerving to witness as a physician neurologist because of its dramatic presentation and rapid evolution; the syndrome is self-limited with the boxer returning to baseline neurological function usually in the ring itself. It likely has the bulk of its anatomical focus in the brainstem with some cortical and subcortical contribution.


Understanding the neuroanatomical correlates of an acute SRC as in boxing has important implications for our conceptual understanding of concussion and acute management of these injuries in the ring.




  1. McCrory P, Meeuwisse W, Dvorak J, et al Consensus statement on concussion in sport—the 5thinternational conference on concussion in sport held in Berlin, October 2016. British Journal of Sports Medicine 2017; 51:838-847.


  1. Ommaya A. Head injury mechanisms and the concept of preventative management: a review and critical synthesis. J Neurotrauma1995; 12:527–46.



  1. Ommaya AK, Gennarelli TA. Cerebral concussion and traumatic unconsciousness. Correlation of experimental and clinical observations of blunt head injuries. Brain1974; 97:633–54.


  1. McCrory P. The nature of concussion: a speculative hypothesis. British Journal of Sports Medicine 2001; 35:146-147.


Head injuries sustained while playing contact sports such as boxing, ice-hockey and football—how concerned should we be about chronic traumatic encephalopathy?-A neurologist’s viewpoint

Head injuries sustained while playing contact sports such as boxing, ice-hockey and football—how concerned should we be about chronic traumatic encephalopathy?-A neurologist’s viewpoint

Nitin K Sethi


Department of Neurology, New York-Presbyterian Hospital, Weill Cornell Medical Center, New York, NY (U.S.A.)

Address for correspondence:

Nitin K. Sethi, MD


New York-Presbyterian Hospital


525 East, 68th Street

New York, NY10065

Tel: + 212-746-2346

Fax: + 212-746-8845



The problem

Head injuries frequently occur while playing contact sports such as boxing, ice-hockey, American football, mixed martial arts (MMA) and even soccer. In sports such as boxing and MMA the goal is to knock out your opponent by causing a concussion. The perils of boxing are thus well recognized by the medical community especially by neurologists.  Boxer’s encephalopathy, punch-drunk syndrome and dementia pugilistica are terms used to describe the neurodegenerative changes seen in professional boxers as well as athletes in other contact sports who suffer repeated concussions during their professional careers. There is now increasing evidence that repeated concussions sustained by a boxer or an athlete in his or her professional career predisposes them to memory problems later on in life (says in their 40’s and 50’s) and Alzheimer’s disease (dementia) like pathological changes are visible in the brain on histopathology. These athletes are also plagued by neuropsychiatric disorders such as anxiety and depression in their later years. Parkinsonian features (problems with gait and balance) may appear later in life due to damage to the deep grey nuclei of the brain.

My own love for boxing

With this increased awareness about the perils of repeated concussions there is a thrust to make these sports safer. But can boxing, MMA and American football be made safer? It is ironic that I was personally drawn to boxing near about the time I started my neurology residency in Saint Vincent’s Hospital and Medical Center in New York.  Prior to that I knew little if anything about this sport. I had just joined a new gym and happened to walk into a boxing class. I was standing outside peeping in when Tyrone the boxing coach yelled out at me across the room. The first class is free come in he said. There and then my love for boxing was born. Since that fateful day 7 years ago, I have grown to love this sport. I have been boxing on and off since then, yes at times I spar usually with boxers who I know won’t throw a wild punch. For one to really understand this sport and the men and women behind it, one needs to spend time in a boxing gym. New York can boast of some world famous boxing gyms such as Gleason’s gym, I call Mendez boxing on 26th Street and 6th Avenue home. There I am known simply as doc. I see the passion and discipline in the men and women who train there especially the ones who are fighting on the amateur and professional circuits. Most of them are in the age range of 16-25. During my time at Mendez I have had the opportunity to closely observe how these men and women train and I tell you it is grueling. Most start with jumping rope for about 10-15 minutes. Then shadow boxing, a few rounds on the heavy bag and pad work. Then come the sparring sessions which can be highly entertaining to watch.  Most boxers end their work-out by going a few rounds on the speed bag. I can honestly say that boxing has changed me for the better; both in mind and in body. So I recently applied and got accepted to be a panel physician for the New York Athletic (boxing) Commission. I feel this shall accord be a unique opportunity to closely observe professional boxing from a neurologist’s point of view.

Making boxing and football safer

So how can we make boxing and other contact sports safer? Some say the best way is to change the rules that govern these sports. In the case of American football one option would be to limit aggressive and hard tackles that encourage helmet to helmet collisions. There has been a healthy debate on this subject. Some have advised better quality helmets the kind worn by soldiers in the battlefield to prevent traumatic brain injury (TBI). The new military helmets (advanced combat helmets) are especially designed to prevent TBI following an improvised explosive device detonation though it is still debatable whether the helmets actually do achieve this objective. The players helmets can be further fitted with a sensor which records the force of impact. This data can then be readily accessed by a physician on the sideline and a timely decision can be made to either pull a player out of play or allow him to continue after a concussion. We certainly have the technology to do this at present but do we know how to analyze the data? Like for example how much should the concussive force be to warrant pulling a player out of a critical game? Some advocate that the rules be amended more drastically such as a complete ban on head to head collisions be enforced. Players should be taught to tackle leading with their shoulder and not using their head as a battering ram. Or that helmets be taken away completely so that players and coaches are forced to switch to “safer” tactics. The main problem with some of these rather novel ideas is that you risk changing the very nature of the sport and driving away the fans. Coming back to boxing you all would agree that most of us go to a boxing match to see a hard knockout. Any Iron Mike fan shall testify to that! Boxing would not be boxing if the rules were amended so that blows to the head were not allowed and professional boxers were forced to wear protective head gear.  So when it comes to boxing and MMA a more “practical” solution would be to enhance our ability to detect concussions in a more comprehensive and timely fashion. But this itself is no easy task. Anyone can identify a concussion when the boxer is knocked out and suffers prolonged loss of consciousness (>5 minutes). Over and out! However it is the minor/subtle concussions which are harder to detect. At present this is what happens. A boxer goes down and a ring side physician like me jumps into the ring to assess him. Are you Okay? Do you want to go on? Raise your gloves for me. Track my finger with your eyes. If he is able to answer my questions and follow my commands, I clear him to fight further. Studies though show that many concussions are missed if examined in this rudimentary fashion. Grossly the boxer looks fine but he is not. There are a few well documented cases where in the boxer has gone on to fight after sustaining a concussion and even win the fight only to be found dead in his bed the next day (second impact syndrome). So is there any better way to identify concussions in a timely fashion?

The Kind Devick test ( has been found to be quite sensitive in identifying concussions. It basically involves the testee reading a set of numbers off a card. The number of errors and time taken to accomplish this task is recorded and can be used to assess if a concussion has occurred. This test can be administered to boxers and other athletes prior to the fight or game and these scores serve as the baseline scores. If the boxer gets hit during the fight or a football player suffers a concussion on the field, the test can be administered on the sidelines and a decision to either pull the player/boxer or to let him continue can be made. The Kind Devick test has some inherent advantages. It is easy to administer by anyone (not just a physician), the test can be administered through hand held cards or on the Ipad, quick to administer (this is very helpful when it comes to boxing since the decision to stop or continue the fight has to be made in a matter of minutes), finally it can be administered ringside or on the sidelines.

Other ways to make boxing, American football and MMA safer include yearly neuropsychological testing of all participants to identify deficits in memory, cognition and other neuropsychiatric morbidities such as anxiety and depression. Serial  MRI scans of the brain should be carried out during the athletes career and a physician trained in the neurosciences such as a neurologist or neurosurgeon should be present ringside in all professional and amateur fights/ games (I agree this is not a very practical solution).

Final thoughts

Finally knowledge is power and all athletes, their coaches, parents of children who indulge in contact sports should be made aware of the perils of repeated concussions, how to identify and avoid them. Working together we can certainly making boxing and American football safer.

Bumps to the head: minor concussion and post concussive symptoms

Recently I have seen a few patients in my office with minor concussions. They all pressented with post concussive symptoms and hence that shall be the focus of my post on this gorgeous June day.  So what is a concussion and what is a “minor” concussion? Concussion is usually a closed head injury with temporary loss of brain function or rather loss of consciousness. By closed head injury, I mean that nothing penetrated the brain. Example of a penetrating head injury shall be a gun shot wound to the head.  Do not get me wrong here-obviously a penetrating head injury shall likely result in loss of consciousness and temporary or permanent loss of some brain function.

That said the word concussion is more commonly used for closed head injuries. Let me give you a few prime examples of concussion.  I am a big fan of boxing and the UFC. Anyone who watches these sports has seen a concussion. Boxer A walks into a stiff jab thrown by Boxer B. Down he goes and is out for the count. The ringside doctor jumps into the ring to examine him. Flips his eyes open and flashes a light into both of them.  After a momentary loss of consciousness, our fallen boxer comes to. Open his eyes but has a dazed look. He is able to answer the ringside doctors questions (show me two fingers with your left hand). He struggles to his feet but his legs are wobbly.  The referee consults the doctor and decides to halt the fight.  So what happened to our boxer? He just sustained a concussion.

Concussions can be graded into mild, moderate and severe. This is quite arbitrary. If the loss of consciousness is more than half an hour the concussion is graded as severe. Minor concussions, which shall be the focus of our talk henceforth, are usually associated with either no or momentary loss of consciousness.  Let me give you a few examples of minor concussions. Walking into a door, bumping your head against a low lying ceiling or a car door are all examples of minor closed head injury with or without concussion.  Majority of patients walk away from such an injury and never seek any medical attention because they experience no ill-effects. A few though  are not so lucky and post the head injury are plagued by headache (post concussive headache), problems with memory and concentration (especially when they are multi-tasking) and a myriad of other complaints such as subjectively feeling off balance, difficulty with sleeping and mood changes such as irritability. All these symptoms after a closed head injury/ concussion are included under the umbrella of post concussive symptoms.

In my next post, I  shall discuss post concussive syndrome and its treatment.

Nitin Sethi, MD

Concussion during sports and return to play decisions

                                      Concussion during sports and return to play decisions

Nitin K Sethi, MD

Assistant Professor of Neurology

New York-Presbyterian Hospital

Weill Cornell Medical Center

New York, NY 10065

I recently read an article in the Archives of Neurology ( Vol 65, Sep 2008) by Dr. Lester Mayers about return to play (RTP) criteria after athletic concussion. As concussions are relatively common sport related injuries (especially in contact sports like football, rugby and boxing) I thought it would be a good idea to review some of the salient points of the article in this forum.

Concussion is a common type of traumatic brain injury and has been referred to by other names such as mild traumatic brain injury, mild head injury and minor head trauma. No good defination for concussion exists though it is frequently described as head injury with transient loss of brain function (usually a short period of loss of consciousness occurs).

Let me explain with the help of an example. I love to box (true one of the few neurologist who actually likes boxing). Lets assume I am going a couple of rounds in the ring with another guy.  A southpaw with a mean right hand. First round here we go!!!. I got my right and left combinations going. Hmmm feeling good and then it happens. I walk into his right. BOOOOOM!!! My knees give in and I hit the canvas. I see stars shining and birds twittering. The referee is asking me “Are you okay? Are you okay?” I look dazed and then slowly come around and answer I am fine. I am helped out of the ring, the fight is over!!! THERE I JUST HAD MY FIRST CONCUSSION!!!

Can I return to play/ box after a 10 mins break?

 Or rather should I return to play after a break?

Is it safe?

 Am I okay?

All these questions are addressed by Dr. Mayers in his review. Traditionally return to play decisions are made by the field side by the team physician or in the case of boxing by the doctor at the ringside. This is usually a clinical judgement with doctors relying on the documentation of resolution of symptoms at rest and during exertion to provide an estimate of the appropiate time for the athletes to resume practice and play (return to play).

A stepwise process was outlined by the Canadian Academy of Sports Medicine:

Step 1: no activity, no play and complete rest till asymptomatic and with a normal neurological examination–if your clear this then Step 2: light aerobic exercise permitted, no resistance training–if you clear this then Step 3: can return to sports specific training and resistance training—if patient remains asymptomatic then can be cleared for Step 4: non-contact training can begin–if patient remains asymptomatic then he is cleared for Step 5: full contact training —if he still remains asymptomatic then he is cleared for Step 6-full play!!! (As you can imagine these criteria are for professional atheletes but also apply for others)

As you can see there are steps to be followed before return to play can be allowed. If you fail one step you go back to the previous step and remain there till you feel better and are ready to proceed further.

Why is this important? Studies have shown that even simple concussions cause cerebral dysfunction (reflecting damage to the brain at the celluar level) and that it takes a minimum of 4 weeks for the brain to revert back to normal. If RTP occurs earlier, the athlete is at risk for a recurrent concussion and further brain damage. Even death can occur (we have all heard of boxers who die during or shortly after a bout).

Learning points from Dr. Mayers review:

1) Concussions are common.

2) Concussions can be serious and even fatal.

3) Concussions lead to cerebral dysfunction and damage to the brain at the cellular level.

4) Return to play decision should be made by a doctor skilled in this task.  A postconcussion RTP interval of at least 4 weeks is imperative (Dr. Mayers takes pain to point out that even more time may be needed to permit complete brain healing and recovery).

My advise to you:

1) Treat a concussion with respect and see a doctor if you suffer one.

2) You may feel you are okay but you are not. The brain takes time to heal completely from a concussion.

3) Do not return to play. See a doctor and get his advise. Let him decide what the return to play interval should be.