Brain Injury

A brain injury refers to any damage caused to the brain that results in the destruction or degeneration of brain cells. When the injury is caused by trauma, meaning by an external mechanical impact, it is called traumatic brain injury or traumatic cranial injury. Brain injuries affect brain function to varying degrees. They present a wide range of symptoms and consequences, which can be mild and temporary, cause permanent damage, or even lead to death.

Depending on how the injury occurs, there are two main types of traumatic brain injury:

• Closed or blunt brain injury: the skull does not crack or fracture.
• Open or penetrating brain injury: the skull is perforated by an object that can also penetrate the brain.

Among the most common traumatic brain injuries are the following:

• Epidural hematoma: blood accumulation between the skull and the outer layer of tissue covering the brain (dura mater).
• Subdural hematoma: blood accumulates between the outer layer and the middle layer (arachnoid).
• Subarachnoid hemorrhage: uncontrolled bleeding in the space between the arachnoid and the inner layer (pia mater).
• Cerebral contusion: hematoma in the brain tissues. Typically, it presents with edema (swelling).
• Concussion: brain impact against the skull due to trauma. It is the most common type of traumatic brain injury and is generally mild.
• Skull fracture: breakage of the cranial bone.
• Diffuse axonal injury: widespread and generalized rupture of axonal fibers and the myelin sheaths of neurons.
• Cerebral laceration: brain perforation.
• Hydrocephalus: accumulation of cerebrospinal fluid in the skull.

Symptoms

The symptoms of a brain injury depend on its severity. Symptoms can appear immediately after the trauma or days later and may persist for an extended period.

• Mild brain injury symptoms:
  • Headache.
  • Confusion or dazed feeling.
  • Dizziness and vertigo.
  • Nausea and vomiting.
  • Blurry vision.
  • Ringing in the ears.
  • Sensitivity to light or sound.
  • Brief loss of consciousness.
  • Problems with concentration or memory. o Fatigue and drowsiness.
• Moderate to severe brain injury symptoms: the following symptoms are added to the ones mentioned above:
  • Prolonged loss of consciousness.
  • Constant or worsening headache.
  • Recurrent vomiting.
  • Seizures.
  • Dilated pupils.
  • Eye or nasal discharge.
  • Extreme drowsiness.
  • Weakness or numbness in the fingers.
  • Speech difficulties.
  • Loss of coordination.
  • Notable confusion or disorientation.
  • Behavioral changes.
  • Coma.

Causes

Closed head trauma is primarily caused by direct blows with objects or falls, especially in children and the elderly. It is also a common injury in traffic accidents or extreme and high-impact sports, particularly in young adults. Penetrating brain trauma, on the other hand, is usually caused by stab wounds, gunshot wounds, or perforations caused by bone fragments.

Risk Factors

The likelihood of suffering a traumatic brain injury increases under the following circumstances:

• Age: more frequent in children under four years, young adults between 15 and 25, and elderly adults over 60.
• Gender: more common in men.
• Participation in high-risk sports.
• Reckless driving.
• Suffering attacks or assaults.
• Military personnel exposed to explosive blasts.

Complications

A traumatic brain injury can cause significant changes in the state of consciousness, ranging from temporary coma to permanent vegetative state or brain death, an irreversible condition. When damage occurs to the brain's blood vessels, an ischemic stroke may occur due to blood clots blocking blood flow to the brain, leading to immediate neuronal death. This can severely damage the brain and even be fatal. Additionally, penetrating trauma increases the risk of bacteria entering the brain, potentially causing severe infections such as meningitis.

Another common consequence of brain trauma is increased intracranial pressure due to the accumulation of cerebrospinal fluid, bleeding, or inflammation. This pressure can permanently damage the brain or spinal cord or even cause death. Moreover, if the trauma has affected the cranial nerves, which emerge directly from the brain, severe neurological disorders may occur, such as facial paralysis, difficulty swallowing, loss or alteration of the sense of taste and smell, or vision and hearing problems.

As for cognitive sequelae, alterations in intellectual abilities may develop, with issues in learning, memory, reasoning, concentration, or comprehension, as well as difficulties in reading, writing, or communicating. Behavioral and conduct changes, such as impulsivity, aggression, insomnia, or depression, may also be observed.

Prevention

Preventing traumatic brain injuries involves trying to avoid accidents:

• Drive carefully, always wearing a seatbelt and using airbags.
• Never drive under the influence of alcohol or drugs.
• Wear a helmet when engaging in high-risk sports or activities prone to falls.
• Reduce the risk of falls by avoiding slippery surfaces, using handrails on stairs, paying attention to the ground and surroundings while walking, etc.

Which doctor treats brain injuries?

Traumatic brain injuries are treated by specialists in traffic medicine, neurology, and neurosurgery.