Introduction:
A traumatic brain injury is a physical damage to the brain tissue that leads to a temporary or permanent impairment of brain function. The diagnosis of this condition is established by imaging tests such as MRI (magnetic resonance imaging) and CT (computed tomography). Initial treatment includes ensuring a normal airway and maintaining adequate ventilation and blood pressure. Surgery is often needed in a patient with severe injury, and after the treatment, it is essential to maintain adequate brain perfusion and oxygenation and prevent complications.
What Is Traumatic Brain Injury?
Traumatic brain injury (TBI) can result from a violent blow or push to the head or body or from an object such as a bullet or piece of skull that may go through the brain tissues. However, not every blow or jolt to the head causes a traumatic brain injury. Mild traumatic injuries can cause temporary or short-term problems with normal brain function, including problems like communication, thinking, understanding, and movements. On the other hand, serious injuries can result in torn tissues and bleeding or may even cause permanent disability and even death. Some of these injuries may be primary, meaning the damage is immediate, and others might be secondary, meaning they can occur slowly over hours, days, or weeks.
What Are the Types of Head Injuries?
Head injuries may involve structural changes ranging from microscopic to gross, depending upon the force of impact. Patients with mild injuries may have no gross structural damage, and clinical manifestations vary due to the severity of the injury. Traumatic brain injuries are categorized as open and closed -
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Open Head Injuries (Penetrating Traumatic Brain Injury) - This involves penetration of the scalp and skull due to objects like bullets, shrapnel, bone fragments, or a knife or a hammer. This can lead to a skull fracture with lacerations due to blunt force, leading to open injury.
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Closed Head Injuries (Non-penetrating Traumatic Brain Injury) - This type of injury is caused by an external strong force that is enough to move the brain within the skull. These types of injuries occur when the head is hit with an object or is shaken violently, causing sudden brain acceleration or deceleration. This can occur due to falls, motor vehicle crashes, sports injuries, or blast injuries.
What Is the Epidemiology of Traumatic Brain Injury?
Traumatic brain injuries are most commonly seen in young patients and mostly in men (75 percent of the cases). Sport is considered one of the common causes of mild repeated head injuries, which can lead to chronic traumatic encephalopathy, a type of neurodegenerative disease, and more severe injuries that occur due to vehicle accidents and assaults.
When to See a Doctor After a Traumatic Brain Injury?
Patients should take traumatic brain injuries seriously as they are linked to the brain, and if they experience loss of consciousness, they should immediately seek medical help. Given below are some of the symptoms that should be considered before getting medical assistance -
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Headache -This is one of the most common symptoms of traumatic brain injury and is often referred to as post-traumatic headache. This can be seen in 30 percent of the individuals that may continue after injury.
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Restlessness - This is one of the most problematic behaviors that can be seen in the case of TBI.
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Slurred Speech - Speaking extremely slowly or fast.
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Vomiting - Vomiting after an injury could be a direct sign of a more severe neurological injury. Patients may experience vomiting or nausea even after days or weeks following a concussion. This can also be linked with migraines.
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Drowsiness - Patients may experience fatigue or increased drowsiness and may experience it more frequently and quickly than the general population. This may lead to less efficient brain functioning.
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Change in Pupil - Injury may cause dilation of the pupils or may cause double vision.
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Confusion - Due to strong jolts, patients may get confused or forget their names or other personal information.
In case a patient is experiencing any of these symptoms, they should see a doctor as soon as possible and get a required MRI scan done, as there can be internal bleeding or swelling in the brain.
What Are the Imaging Techniques to Diagnose Traumatic Brain Injury?
I. Initial Assessment -
The initial evaluation of all the injuries is done by the healthcare professional before providing any treatment. Airway sufficiency and breathing are assessed. Diagnosis and treatment are carried out simultaneously in seriously injured patients.
In the initial assessment, a complete neurologic evaluation is done, which includes the Glasgow Coma Scale (GCS) and pupillary light response. Patients are reassessed every 15 to 30 minutes initially and then one hour after stabilization. This helps in estimating the severity of the injury and its prognosis.
Glasgow Coma Scale - This is a 15-point test that helps doctors assess the severity of the brain injury by checking the motor abilities, eye movement, and speech. The abilities to move or speak are scored from 3 to 15, and a higher score means less severe injuries.
II. Complete Clinical Evaluation -
A complete neurologic examination is done when the patient is stable.
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Children and infants should be carefully examined for retinal hemorrhages.
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A concussion is diagnosed if the patient has lost consciousness or memory loss.
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Funduscopic examination is done in adults to examine retinal detachment and the absence of retinal venous pulsations because of high intracranial pressure (ICP).
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Microhemorrhages can be seen on MRI or CT scans when the loss of consciousness is there for more than six hours.
III. Neuroimaging -
The diagnosis of traumatic injury is usually made by MRI (magnetic resonance imaging) and CT (computed tomography). Imaging is required in patients with impaired consciousness, persistent vomiting, seizures, or clinically suspected fractures.
Noncontrast Head CT Scans -
Skull fractures can also be diagnosed with the help of X-rays, but they are usually not done in these cases. Therefore, in these cases, CT (computed tomography) is the best choice for imaging as it can detect hematomas, skull fractures, and even diffuse axonal injury.
Some of the following findings can be seen in the CT scan -
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Acute bleeding and contusions may appear in the scan as compared to other brain tissues.
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Subdural hematomas (blood collection between the brain and its outermost covering) may appear as crescent-shaped opacities overlying brain tissue.
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A chronic subdural hematoma can appear less dense (hypodense) as compared to other brain tissues, whereas a subacute subdural hematoma may show the same radiopacity as brain tissues (isodense). However, these findings may vary in patients.
Magnetic Resonance Imaging -
MRI scans may be done later in the treatment to detect more minute contusions and brain stem injuries. MRI is considered more sensitive than computed tomography for diagnosing very small acute or isodense subdural hematomas. According to some studies, it has also been found that MTI helps predict prognosis much better than CT.
CT angiography, magnetic resonance angiography, and angiography are all useful techniques that can be used to identify vascular injury.
Conclusion:
Diagnostic imaging techniques play a crucial role in identifying and treating conditions related to traumatic brain injuries. There have been many technical improvements in imaging techniques that reduce the scanning time and improve the quality of the images. New methods are being developed to enhance imaging quality and improve predictive power. Therefore, imaging techniques play a vital role in identifying the damage and formulating a treatment plan.
