What Is a Head Injury?
A head injury can be a minor accident or a life-threatening emergency. Some could be as simple as a bruise on the scalp that will heal in days with no long-term effects. Others could be traumatic brain injuries that cause permanent changes to personality and functioning.
Types of Head Injury
Types of head injury depend on the severity of the injury and what part of the head is injured. Injuries to the scalp and skin are usually minor and heal quickly. An injury to the skull or the brain could cause serious damage and result in long-term or permanent effects.
It’s important to understand the types of injuries that can affect the brain and to be able to recognize their symptoms, so you can get treatment quickly if you or someone you know experiences a serious head injury.
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Concussion
A concussion is one of the most common types of traumatic brain injuries. It occurs when your brain is knocked against the inside of the skull. -
Contusion
A more severe concussion can cause a contusion, which is a bruise on the brain which forms when small blood vessels, called capillaries, break, causing bleeding. Just like a bruise on the skin, a contusion can cause swelling or edema that can create pressure on the brain. -
Hematoma
Damage to the brain can also cause more serious bleeding or hematoma. Different types of hematoma are located in different areas inside the skull. Subarachnoid hemorrhage and subdural hemorrhage occur in the tissue surrounding your brain, and intracerebral hemorrhage occurs in the tissue of the brain itself. Any bleeding inside the skull can build up pressure on the brain, so an intracranial hematoma is a serious injury that needs immediate care. -
Skull Fracture
A forceful blow to the head can also cause a skull fracture. Since the skull protects your brain, this is a dangerous injury that should be examined by a neurosurgeon, even if an individual does not experience immediate symptoms. Some skull fractures are linear, which means the skull bone stays in place even though it’s broken. These usually can heal on their own without treatment. A depressed skull fracture, where the skull shape is sunken in the place where it’s broken, is a serious injury that usually requires surgical elevation of the fracture fragments. -
Diffuse Axonal Injury
Like a concussion, a diffuse axonal injury(DAI), is caused by the brain moving in the skull, but this type of injury is very serious. Axons are the long fibers of the nerve cells that carry messages to other cells. There are billions of axons in your brain, and in a DAI, many of them are injured by the shearing motion as the brain is shaken back and forth or by the angular motion of brain by rotation over its stem. Axons are essential for carrying electrical messages throughout your brain. This type of injury usually causes coma, and it often results in death.
What Can Cause a Head Injury?
Head injuries are caused by direct blows to the head or by sudden, sharp movements, such as shaking, that causes the brain to move inside the skull.
Direct blow head injuries are usually caused by motor vehicles accidents or high-impact contact sports, such as football. They can also be caused by falls, fights, and falling objects. Accidental falls are the most common cause of head injuries, usually among young children and elderly adults.
Learn more about the assessment, prevention, and treatment of sports concussions.
Head injuries from shaking are most common among young babies, whose heads are too heavy for the muscles in the neck to support. This type of head injury often referred to as a shaken baby syndrome, occurs when a caregiver shakes the baby violently.
What Are the Symptoms of a Head Injury?
The symptoms of head injury can indicate the severity of the damage to the brain. It’s possible for symptoms to be mild at first and to grow more severe over time as bleeding or swelling inside the skull increases and pressure on the brain grows. That’s why it’s important to pay close attention to symptoms experienced after any type of head injury. If new or more serious symptoms appear, call a doctor immediately.
Early or mild symptoms of head injury include the following:
- Temporary loss of consciousness (less than 30 seconds)
- Loss of memory
- Headache
- Bruise or swelling on the scalp
- Nausea
- Brief confusion
More serious symptoms of a head injury are the following:
- Loss of consciousness for longer than 30 seconds
- Severe headache
- Vomiting
- Increasing confusion
- Slurred speech
- Loss of balance and difficulty walking
- Ongoing dizziness
- Unequal pupils
- Seizures
If you experience any serious symptoms, seek medical help immediately.
Additional symptoms can also appear after time, sometimes as long as weeks after the head injury. These symptoms include the following:
- Difficulty concentrating
- Difficulty forming new memories
- Personality changes
- Irritability
- Hypersensitivity to light
- Changes in smell or taste
If you experience new or changing symptoms after a head injury, seek medical care.
Diagnosing a Head Injury
Diagnosing the severity of a head injury involves knowing the history of what happened, assessing symptoms, and performing diagnostic scans.
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History/Origin of Injury
The history of how the injury occurred is an important tool for diagnosing a head injury. If the injured person experienced a loss of consciousness or memory, then they may not be able to give doctors a full account of what happened. If your loved one experienced a head injury, your account of the event can be very helpful for diagnosis. -
Physical and Neurological Examination
To determine the effect of the injury on brain function, doctors will perform tests that measure both physical and neurological function. One tool for these measurements is the Glasgow Coma Scale, which rates a person’s level of consciousness based on whether they can perform activities such as holding a conversation, moving around, and following commands. A score of 8 or lower is considered a severe head injury, and 9 to 12 is a moderate head injury. A person who experienced a head injury and scores 13 to 15 on the scale is diagnosed with a mild head injury. -
Imaging
A Computed Tomography (CT) scan will show whether there are fractures in the skull. It will also show any bleeding, bruising, or swelling in the brain.
Head Injury Treatment
Mild head injury can be treated with rest and as-needed pain relief. If the doctor determines there is no sign of swelling or bleeding in the brain and symptoms are staying the same or improving, then the patient will probably not need to stay in the hospital. They can monitor symptoms at home to make sure they’re not becoming worse.
In the past, medical professionals recommended waking up every few hours after a head injury because it is difficult to monitor symptoms while asleep. However, rest is one of the most important ways that the body heals. The current recommendation is to rest and sleep as much as possible after a head injury, as long as symptoms are mild and stable.
Serious head injury needs treatment in the hospital. Treatment could include:
- Diuretics to remove fluid and reduce swelling
- Anti-seizure drugs to prevent seizure
- Surgery to repair bleeding, drain fluid, or repair fractures
Rehabilitation
All types of head injuries can cause long-term changes that impact function. Brain injury can cause:
- Personality changes
- Difficulty forming new memories
- Motor impairments
- Difficulty performing daily activities
Rehabilitation treatment depends on the changes caused by the injury. For example, a person who has reduced muscle strength on one side of their body will work with a physical therapist to improve their mobility. A person who has experienced personality changes may work with a neuropsychologist to learn coping strategies and adjust to their new normal. After a head injury, it’s essential to have the support of a multidisciplinary team that can address all the changes caused by the injury.