Concussion | A transient, trauma-induced alteration in mental status that may or may not involve loss of consciousness. Symptoms and signs include headache, nausea, disorientation, irritability, amnesia, clumsiness, visual disturbances, and focal neurologic deficit. | Unknown; likely mild diffuse axonal injury and excitotoxic neuronal injury. Cerebral contusion may occur. |
Cerebral contusion or laceration | Loss of consciousness longer than with concussion. Focal neurologic deficits are often present. May lead to death or severe residual neurologic deficit. | Bruising on side of impact (coup injury) or contralaterally (contrecoup injury). Vasogenic edema, multiple petechial hemorrhages, and mass effect. May have subarachnoid bleeding. Herniation may occur in severe cases. Cerebral laceration specifically involves tearing of the cerebral tissue and pia-arachnoid overlying a contusion. |
Acute epidural hemorrhage | Headache, confusion, somnolence, seizures, and focal deficits occur several hours after injury (lucid interval) and lead to coma, respiratory depression, and death unless treated by surgical evacuation. | Tear in meningeal artery, vein, or dural sinus, leading to hematoma visible on CT scan. |
Acute subdural hemorrhage | Similar to epidural hemorrhage, but interval before onset of symptoms is longer. Neurosurgical consultation for consideration of evacuation. | Hematoma from tear in veins from cortex to superior sagittal sinus or from cerebral laceration, visible on CT scan. |
Cerebral hemorrhage | Generally develops immediately after injury. Clinically resembles hypertensive hemorrhage. Surgery to relieve mass effect is sometimes necessary. | Hematoma, visible on CT scan. |
Diffuse axonal injury | Persistent loss of consciousness, coma, or persistent vegetative state resulting from severe rotational shearing forces or deceleration. | Imaging may be normal or may show tiny, scattered white matter hemorrhages. Histology reveals torn axons. |