What is a concussion?
Concussions are injuries to the brain caused by hits or jolts to the head.
What happens to the brain during a concussion?
The brain floats inside the skull, supported by fluids and membranes. Blows to the head cause the brain to shift and hit the skull, which can lead to bruising of the brain. The impact from the initial blow and the bruising from the shifting of the brain aren’t the only injuries. The shifting of the brain from the impact also hurts the membranes and nerve fibers that support the brain’s position in the skull—an injury called shearing. Long term damage can occur to these nerve fibers—damaging the brain’s ability to communicate. After the initial injuries, the brain produces a series of chemicals to help itself recover. Sometimes these chemicals can do more harm than good, further damaging the brain in their efforts to repair it. Blood flow is reduced in the injured areas of the brain due to damage in the brain’s blood vessels.
Why do some people experience symptoms for a long period of time?
Usually, concussion symptoms go away within 1 to 6 weeks, for some, symptoms can last for months or even years. When symptoms don’t go away within 6 weeks it is called Post Concussive Syndrome. We don’t know why some people develop Post Concussive Syndrome, but it may be that they just experience more damage to the brain during their injury. In general, recovery takes the longest for older adults and children/teens. Recovery can also take longer if it isn’t a person’s first concussion.
Diffuse Axonal Brain Injury
A minor concussion would not bruise or damage your brain cells. But if the concussion is severe enough to cause lasting symptoms for weeks to months, it may have injured the cells deep in your brain. Neurons have a central “head” and long extension that is considered their outlet, called axons. These hair-thin extensions which connect each neuron to its neighboring neuron or to neurons in the other side of the brain, are prone to being stretched, inflamed, or even totally torn.
The sudden rocking movement of the head causes the brain tissue to bang against the inside part of your skull and get bruised. With a traumatic brain injury, especially when your head is hit at an angle, your brain may get twisted and axonal connections get torn. The twisting motion of the brain inside the skull which injures the axons is called Diffuse Axonal Injury. The location of this injury in your brain determines what kind of symptoms you will experience.
If the axonal injury happens in your frontal lobes, you would develop symptoms like difficulty paying attention to what you read, making decisions, doing your homework or job responsibilities that require problem solving, and/or even driving. If your cerebellum is involved, you may walk like a drunk person or have difficulty maintaining your balance.
It is important to keep in mind that a trauma that impacts your brain may also damage your inner ear, your skull, or your spine. If the head trauma damages your inner ear, you may develop significant dizziness and vertigo. If the nerves at the base of your head are injured, you may develop constant neck pain and headaches. And if your spine is injured, you may develop serious paralysis in your arms or legs.
The exact details of what happens in the brain after a traumatic injury is still being worked out by scientists. Sometimes excessive levels of inflammation in the brain can actually cause some harm. Blood flow may also be affected due to damage in the brain’s blood vessels.
Fortunately, the vast majority of patients with traumatic brain injury gain full recovery and move on with their lives within three months. Some patients, however, can have disabling symptoms such as persistent headaches, memory problems, anxiety, insomnia, irritability, or even depression for a long time. Trouble sleeping and feeling constantly tired are some of the symptoms that can ruin one’s daily life.
You may wonder if all concussions are really that bad in the long term? The answer is, they can be. Mild concussions resolve within hours to days. But severe concussions that are associated with loss of consciousness can cause problems for a long time. It is important to keep in mind that sometimes patients with even what seems to be a mild traumatic brain injury can have lingering concussion for months.
When symptoms of a traumatic brain injury persist for more than 3 months, which can happen in about 20-30% of concussions, it is called post-concussion syndrome. You may have heard about this syndrome from the media coverage of common long-term consequences of concussion among athletes in contact sports such as hockey and football.
Patients suffering from persistent post-concussion symptoms may have trouble managing their emotions or have trouble focusing, paying attention, communicating, and processing information on a daily basis. The breakdown in their brains’ communication pathways makes it difficult for them to study, preform their job, or communicate well with their family members. Many of them become overly irritable or depressed and end up losing their job or getting a divorce. This is quite unfortunate, as most of their symptoms are treatable, if they are under the care of physicians who know how to care for concussion patients.
