A concussion is a type of traumatic brain injury (TBI) that occurs when a sudden bump, blow, or jolt to the head or body causes the brain to move rapidly inside the skull. This forceful movement can lead to chemical changes in the brain and sometimes stretch or damage brain cells. Although concussions are usually not life-threatening, their effects can be significant and may last for days, weeks, or even longer, impacting how an individual thinks, feels, acts, and sleeps. Understanding the proper management of concussions, including the role of medical imaging, is an important step in recovery.
Understanding Concussion Diagnosis
A concussion is primarily considered a functional injury, meaning it disrupts how the brain works rather than causing obvious structural damage. This differs from other types of brain injuries that might involve visible bleeding, swelling, or fractures. The injury mechanism involves a temporary alteration in brain function due to mechanical force at a microscopic level.
Diagnosing a concussion typically relies on a thorough clinical assessment, including a detailed patient history and a physical examination. Healthcare providers evaluate symptoms, check neurological functions like reflexes and balance, and conduct cognitive testing to assess memory and concentration. Imaging tests are not usually performed to diagnose a concussion, as the changes are not typically visible on standard scans.
When Imaging Is Recommended
While imaging is not routinely used to diagnose a concussion, it becomes a tool to rule out more serious, life-threatening brain injuries. Healthcare professionals look for specific “red flag” symptoms and circumstances that warrant immediate medical imaging after a head injury. These situations indicate a potential for structural damage like bleeding in or around the brain, or a skull fracture.
Immediate imaging is recommended if there is a loss of consciousness lasting more than 30 seconds or if seizures occur after the injury. Other concerning symptoms that prompt imaging include a headache that worsens or does not go away, persistent or repetitive vomiting, and increasing confusion or difficulty staying awake. Changes in motor function, such as weakness, numbness, or tingling in the arms or legs, also signal a need for urgent assessment.
Balance problems, difficulty walking, slurred speech, or changes in pupil size and vision problems are additional red flags. Any suspicion of a skull fracture or intracranial bleeding, often suggested by the mechanism of injury (e.g., high-impact trauma or a significant fall), also necessitates imaging. Age considerations, such as very young children or elderly individuals, and the use of anticoagulant medications, can also lower the threshold for imaging due to increased risk of complications.
What Imaging Reveals
CT scans and MRIs are powerful tools for evaluating head injuries, but they have different strengths. A CT scan is often the initial imaging choice in emergency situations because it is fast and effective at detecting acute issues like skull fractures, bleeding within the brain (hematomas), or significant swelling. It uses X-rays to create cross-sectional images.
An MRI uses powerful magnets and radio waves to produce more detailed images of soft tissues, making it better for identifying subtle lesions or changes that might not be visible on a CT scan. However, standard MRI and CT scans typically appear normal in cases of isolated concussion because the injury affects brain function at a microscopic level, not gross structural changes. A “normal” scan does not mean a concussion has not occurred; it simply indicates the absence of larger, more serious structural damage.
Beyond Imaging: Clinical Assessment and Recovery
The diagnosis and ongoing management of a concussion are primarily based on clinical evaluation by a healthcare professional. This involves monitoring symptoms, assessing cognitive function, and performing physical examinations, regardless of whether imaging was performed. The clinical picture guides the treatment plan and recovery process.
Concussion recovery emphasizes physical and cognitive rest, followed by a gradual return to activities. Initial recommendations often include relative rest for the first 24-48 hours, allowing for light daily activities as tolerated. As symptoms improve, physical and mental activities are slowly increased, with careful monitoring to avoid symptom flare-ups. Follow-up care is important to manage any persistent symptoms and ensure a safe and effective return to daily life, school, or work.