Head injuries can range from minor bumps to severe trauma. Two commonly misunderstood terms are concussion and contusion, both forms of traumatic brain injury. Understanding their distinct characteristics is important for recognizing symptoms and seeking appropriate medical attention.
Concussion Defined
A concussion is a mild traumatic brain injury that temporarily impacts brain function. It occurs when the brain moves or twists inside the skull, such as from a direct impact or rapid acceleration and deceleration forces. This movement can stretch nerves and blood vessels, causing temporary chemical changes that disrupt the brain’s normal operation. Concussions are functional injuries, affecting how the brain works rather than causing visible structural damage.
Symptoms can appear immediately or develop hours to days later. Common physical signs include headaches, dizziness, nausea, vomiting, balance problems, and sensitivity to light or sound. Cognitive symptoms often involve confusion, feeling “in a fog,” difficulty concentrating, or short-term memory issues. Emotional changes such as irritability or mood swings can also occur.
Contusion Defined
A brain contusion, in contrast, is a structural injury involving bruising or bleeding on the brain tissue. This type of injury typically results from more severe impacts to the head, where the brain collides with the inside of the skull. The force can cause small blood vessels to leak, leading to blood collection within the brain tissue. Contusions can occur directly under the impact site or on the opposite side of the brain, a phenomenon known as a contrecoup injury.
The severity of a contusion can vary. These injuries can lead to localized neurological deficits depending on the affected brain area. Unlike concussions, contusions are often visible on medical imaging techniques such as CT scans or MRIs because they involve tissue damage and bleeding.
Distinguishing Features
The fundamental difference between a concussion and a contusion lies in the nature of the injury. A concussion primarily represents a functional disturbance of brain activity without visible structural damage on standard imaging. The brain’s electrical and chemical processes are temporarily disrupted, leading to a range of symptoms. Conversely, a contusion is a structural injury characterized by bruising or bleeding of the brain tissue, making it detectable on imaging scans.
Visibility on imaging provides a clear distinction: concussions typically do not show up on standard CT or MRI scans, while contusions are often identifiable. While both are serious brain injuries, contusions generally imply more direct tissue damage and can lead to more severe, localized, or persistent neurological deficits. Contusions can also progress, with bleeding potentially increasing in the hours or days following the injury.
Both concussions and contusions share overlapping symptoms, such as headache, confusion, nausea, and memory problems. However, contusions are more likely to present with focal neurological signs, which are problems with specific nerve, spinal cord, or brain functions affecting a particular body region. These can include weakness or paralysis on one side of the body, slurred speech, or vision difficulties, directly corresponding to the bruised brain area. Concussions typically result in more widespread symptoms without these specific localized deficits.
Urgent Medical Care
Immediate medical attention is crucial for any head injury, especially if certain red flag symptoms appear. For both concussions and contusions, signs like loss of consciousness, a severe headache that worsens, repeated vomiting, or seizures necessitate an emergency room visit. Other concerning symptoms include slurred speech, one pupil being larger than the other, fluid or blood draining from the nose or ears, or increasing confusion or agitation.
While concussions are functional injuries, they still require medical evaluation to assess the injury’s extent and guide recovery. Contusions, involving physical damage to brain tissue, are medical emergencies that often require immediate intervention to prevent further complications like increased intracranial pressure. Any changes in behavior, coordination, or level of alertness following a head injury warrant prompt medical assessment.