Concussion: more than just a bump on the head

Posted on 9 May 2018

Here’s what happens after you bump your head: your brain shifts suddenly inside your skull, and this uncontrolled motion stretches, tears and damages your brain cells.

The area where the direct blow has occurred is known as a coup. That initial impact then causes a countercoup, where the brain strikes the inside of the skull, and keeps moving until it rebounds against the other side of the skull. If this sounds bad enough, bear in mind: even once all movement has stopped, your brain is still at risk.

Known as a mild traumatic brain injury (MTBI), concussions are most prevalent in South Africa in contact sports like rugby and soccer, says Dr Nico Enslin, a neurosurgeon at Mediclinic Constantiaberg.

They’re also difficult to diagnose: “Severe forms of concussion, where someone loses consciousness and needs to be taken off the field, are obvious occurrences, but milder, more subtle concussions are often underdiagnosed, and the incidence of those is much higher,” he says.


1. When your head is struck, the force from the impact causes the brain to move violently, striking the inner surface of your skull and rebounding against the opposite side, causing bruising, bleeding and swelling.

2. The jelly-like brain is surrounded by cerebrospinal fluid (CSF) that protects your brain from the hardness of your skull. “But when the force causes a rapid acceleration or deceleration of the head, the CSF is unable to protect your brain, which continues moving towards the opposite side of the skull and bumps hard against it, causing a concussion,” explains Dr Enslin.

3. Rotational forces are even more dangerous, adds Dr Enslin. “The brain can’t cope with any sudden axial rotation movement. When the sudden acceleration of the brain also rotates the brain very suddenly, it causes the brain’s small nerve cells to tear, leading to a severe form of concussion,” he explains.

Internal fallout

Concussion is part of a spectrum of diseases that affect the brain as a whole, says Dr Enslin. “A blow to the head can cause a widespread release of toxic substances from deep parts of the brain, and this can lead to swelling throughout the brain.”

A hard enough bump can disrupt the brain’s normal chemical balance. This causes damage at the nerve-cell level, he warns. “When small nerve cells inside the brain tear, they cause brain cells to break open and leak toxic substances, which then disrupt control of blood flow and blood drainage from the brain. This results in swelling and other adverse symptoms.”

This is why concussion can be fatal, especially if a person suffers multiple incidents. “Repeated blows to the head can lead to chronic brain injury as seen in chronic traumatic encephalopathy (CTE), a progressive, non-curable degeneration of the brain.”

Know the signs

You may not realise at first how serious the injury actually is, as some symptoms may not show for hours or days. “If you are seeing signs like loss of consciousness, headaches, seizures, leakage of fluids through the nose or ears, or if one pupil is larger than another, get the patient to the EC right away to have a brain scan,” advises Dr Enslin.

Each individual may experience these symptoms somewhat differently. “Children experience the same symptoms as adults do, but it’s more difficult for them to voice exactly how they’re feeling. Parents need to look out for any adverse change in their child’s behaviour, such as increased crying and irritability,” advises Dr Enslin.


● Headache
● Nausea or vomiting
● Balance problems
● Dizziness
● Fuzzy or blurry vision
● Feeling tired and lacking energy
● Sensitivity to noise or light
● Ringing in the ears
● Slurred speech
● Loss of consciousness
● Convulsions or seizures
● Leakage of fluids through the nose or ears
● One pupil is larger than another
● Any new-onset weakness

“Most people don’t lose consciousness when concussed, but it is possible,” says Dr Enslin.


● Difficulty thinking clearly
●  Feeling slowed down
●  Difficulty concentrating
●  Difficulty remembering new information
●  Slowed reaction times
●  Amnesia, specifically short-term memory loss


● Irritability
● Sadness
● More emotional
● Nervousness or anxiety
● Changes in personality
● More impulsive


● Sleeping more than usual
● Sleeping less than usual
● Trouble falling asleep
● Not feeling rested after sleep

Published in Magazine

In the interest of our patients, in accordance with SA law and our commitment to expertise, Mediclinic cannot subscribe to the practice of online diagnosis. Please consult a medical professional for specific medical advice. If you have any major concerns, please see your doctor for an assessment. If you have any cause for concern, your GP will be able to direct you to the appropriate specialists.

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