Hello everyone and welcome to this week's blog post. In this article, I will be discussing concussion. In this article, I will first explain what a concussion is and what its symptoms are. I will then address its molecular causes, before discussing how it can be detected, treated and prevented.
What is a concussion?
A concussion is a temporary, traumatic brain injury which occurs after an impact to the head (such as bumping the head against something or getting hit with an object). A concussion can also commonly occur following a car accident, due to whiplash. It is a reasonably common brain injury - according to the CDC, there were around 173,000 people under the age of 19 who required hospital treatment for concussion between 2001 to 2009 in the United States alone. Typically, the injury is only temporary and the patient would have fully recovered a few days or a week after the impact.
What are the symptoms of a concussion?
Concussions are not usually life-threatening. Nonetheless, they commonly have several unpleasant symptoms including confusion, dizziness, nausea, balance difficulties. In addition, some people also experience ringing sounds in their ears and increased sensitivity to light.
It is important to note that, while symptoms of a concussion are usually apparent a few minutes or hours following the injury, they can take a few days to manifest. Consequently, it is important that people who receive impacts to their head keep an eye out for any symptoms of concussion over the following days to ensure that medical care is not required.
These more serious symptoms include repeated unconsciousness, memory problems, a persistent headache, weakness in the arms or legs, clear fluid coming out of their ears or nose, seizures and vision problems.
In the UK, people are not advised to seek immediate medical care for minor head injuries whose symptoms are very mild (such as feeling sick and a mild headache) and disappear within a few days of the incident. This is because they are likely to not be concussions. If there is any doubt about whether it is a concussion or not, NHS 111 can provide guidance about whether it is necessary for a patient to go to their local A&E.
Patients who suffer serious symptoms or have risk factors which increase the chances of them receiving a concussion (such as alcohol consumption, taking blood-thinning medication or consuming recreational drugs) are advised to seek immediate medical advice. This is because concussions can often lead to bleeding occurring in the brain. This is often fatal if not treated quickly.
Children are more likely to get a concussion than adults, as they are more accident-prone. They also have disproportionately large heads compared to the rest of their body, which makes it more likely that their head will bump against something. Since toddlers and young children can't communicate their symptoms as easily or describe how they feel, it is incredibly important for parents and carers to observe their children if they receive a bump to the head, in case they have a concussion.
What are the causes of a concussion?
Concussions arise because the brain is a soft organ (it has the consistency of gelatin) that is housed in the skull. The area between the brain and the skull is filled with cerebrospinal fluid, which helps cushion the brain from bumps. If someone receives a significant impact to their head, this force can jolt the brain and cause it to move around inside the skull. Sudden accelerations and decelerations can also cause this to occur.
As a result, there is a sudden release of neurotransmitters in the brain. One of these groups of neurotransmitters is glutamate binding neurotransmitters. Glutamate is one of the most vital neurotransmitters in the human brain, accounting for over 90% of the synaptic connections. However, high concentrations of this neurotransmitter overexcite cells, resulting in cellular damage. In addition, if the concentration of glutamate remains high for too long, then neural cells become oversensitive. Both of these factors contribute to cognitive impairments following concussions.
Furthermore, concussions also cause the release of potassium into the extracellular outside cells; consequently, calcium is absorbed by brain cells. According to a paper published in the Americal Journal of Medicine, if this calcium accumulates in the mitochondria and remains there for a long period of time, then this can result in the axons of the neurones being damaged, thus further exacerbating the possible cognitive impairments following stroke.
When the brain is jolted, it can also be bruised. This can cause injury to the nerves and damage to the blood vessels in the brain. This bleeding can be fatal as not only does it reduce the oxygen supply to brain cells, but it also increases the pressure on the brain and causes it to swell, thus killing brain cells.
How can a concussion be detected?
If someone receives a concussion, it is usually first detected by the person or people around them noticing signs and symptoms associated with concussions. Some sports coaches are also trained in pupil response tests to judge whether a concussion is likely to have occurred. In these cases, after seeking medical care, the patient will likely receive a CT scan to check for damage to the brain.
In the future, according to a study published in the BMJ Paediatrics Open 2019, concussions could be tested for using a blood test. This blood test would test for the presence of two different proteins (GFAP and UCH-L1) that are found in the blood in higher concentrations after concussive injuries. According to these researchers, this technology is only a couple of years from being used in hospitals.
If this works, then this blood test could potentially revolutionise the detection of concussions. Normally, CT scans have to be used to diagnose someone with a concussion. However, not only do these scans expose patients to potentially harmful radiation, but they also are not very effective at detecting more minor concussions. Indeed, the vast majority of patients with minor concussions (which may still need treatment) have normal CT scans. A blood test would significantly reduce the cost of diagnosis, increase its effectiveness and reduce the potential harm for the patient.
How are concussions treated?
The brain is an incredibly complex organ. Consequently, concussions are treated on an individual, case-by-case basis, depending on the severity of the damage and the area where the damage occurred. Once an MRI or CT scan has been conducted to rule out major brain injury, patients are discharged from hospitals to recover from their concussion at home. The brain will mostly recover from minor brain injuries by itself, however, there are many things that someone can do to help recovery.
For example, recovery can be improved by resting, avoiding stress, and not consuming alcohol. Medications, such as paracetamol and ibuprofen, can also be taken to treat headaches. In addition, people should also avoid sports, strenuous exercise and riding motorcycles until they have fully recovered, as this gives the brain time to recover.
If the concussion is severe, then the patient may require a combination of medical treatments. For example, neurological medications may include diuretics (to reduce pressure inside the brain), anti-seizure drugs and coma-inducing drugs. These coma-inducing drugs are used as they reduce the oxygen requirements of the cells in the brain, thus allowing the body to survive if oxygen supply is restricted.
Surgery may also be needed to remove blood clots, relieve intracranial pressure and stop blood vessels bleeding. Additionally, people who suffer major concussions may also need significant rehabilitation to allow them to regain the ability to perform basic skills, such as walking or talking.
What are the complications of a concussion?
One of the main complications of a concussion is a condition called post-concussion syndrome. Patients who had this condition, which occurs following a concussion or another brain injury, reported having symptoms such as headache, dizziness, cognitive impairments, anxiety and problems sleeping. In some cases, these symptoms can last for a significant period of time following a concussion and can affect people's daily lives.
In addition, other possible complications of concussions include post-traumatic headaches, dizziness and vertigo. Furthermore, if someone receives multiple concussions over a relatively short period of time, then they are at a much higher risk of getting permanent brain damage.
How can concussions be prevented?
The best way to prevent concussions is to reduce the force that impacts to the head exert on the skull. For example, this can be achieved by wearing seatbelts when driving or by wearing helmets when cycling. In addition, helmets and safety gear should also be worn by athletes. Furthermore, regular exercise can also help improve your balance and thus reduce the chances of falling and getting injured.
Sources:
Mullally, William J. 2017. "Concussion". The American Journal Of Medicine 130 (8): 885-892. doi:10.1016/j.amjmed.2017.04.016.
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