SDHs occur as a result of bleeding between the dura and the arachnoid membranes covering the brain parenchyma They may result from direct trauma or from shaking injuries and are typically due to tearing of the cortical bridging veins or due to bleeding from the cortex itself SDHs may be bilateral, and frequently, there is an associated underlying brain injury Skull fractures occur in only a minority of cases Children with SDHs often have seizures, may present with evidence of acutely elevated ICP, or may have more nonspecific signs of vomiting, irritability, or low-grade fever Physical examination often reveals an irritable or lethargic child, with a bulging fontanel in infants, who may or may not have neurologic abnormalities CT scan commonly demonstrates crescent-shaped subdural collections Intracerebral Hematoma Posttraumatic intracerebral hematomas are unusual in children Blood within the parenchyma is usually the result of severe focal injury or penetrating trauma, usually manifests with severe neurologic compromise, and often portends a poor prognosis Subarachnoid Hemorrhage Subarachnoid hemorrhage may occur following head trauma (including shaking injuries in infants) and may cause headache, neck stiffness, and lethargy in the child Diffuse Axonal Injury Diffuse axonal injury is characterized by injury to the white matter tracts of the brain and is one of the most common causes of prolonged posttraumatic coma in children The initial CT scan may be normal or may demonstrate multiple petechial hemorrhages in the deep white matter and central structures The degree of microscopic injury is usually greater than that seen on CT imaging and MRI may be more sensitive in accounting for clinical symptoms that are disproportionate to (seemingly mild) CT-scan findings Cerebral Edema Diffuse cerebral edema occurs frequently in children with severe head trauma It appears to be a reactive phenomenon that occurs within hours of the traumatic event and is likely a final common manifestation of brain injury caused by a variety of pathophysiologic processes The major effect of this swelling is potential for significant elevation of ICP These children have a depressed level of consciousness and may have focal neurologic signs or symptoms of herniation