Blood is seen layering into the brain along sulci and fissures, or filling cisterns (most often the suprasellar cistern because of the presence of the vessels of the circle of Willis and their branch points within that space). The classic presentation of subarachnoid hemorrhage is the sudden onset of a severe headache (a thunderclap headache). This can be a very dangerous entity and requires emergent neurosurgical evaluation and sometimes urgent intervention. Cerebral contusion
Cerebral contusion is bruising of the brain tissue. The piamater is not breached in contusion in contrary to lacerations. The majority of contusions occur in the frontal and temporal lobes. Complications may include cerebral edema and transtentorial herniation. The goal of treatment should be to treat the increased intracranial pressure. The prognosis is guarded. Diffuse axonal injury
Diffuse axonal injury, or DAI, usually occurs as the result of an acceleration or deceleration motion, not necessarily an impact. Axons are stretched and damaged when parts of the brain of differing density slide over one another. Prognoses vary widely depending on the extent of the damage. Compound head injury
Overlying scalp laceration and soft tissue disruption in continuity with a skull fracture constitutes "compound head injury", and has higher rates of infection, unfavorable neurologic outcome, delayed seizures, mortality, and duration of hospital stay. Signs and symptoms
Three categories used for classifying the severity of brain injuries are mild, moderate or severe. Mild brain injuries
Symptoms of a mild brain injury include headaches, confusion, ringing ears, fatigue, changes in sleep patterns, mood or behavior.
The widely used PECARN Pediatric Head Injury/Trauma Algorithm helps physicians weigh risk-benefit of imaging in a clinical setting given multiple factors about the patient—including mechanism/location of the injury, age of the patient, and GCS score. Location of brain damage predicts symptoms
Symptoms of brain injuries can also be influenced by the location of the injury and as a result, impairments are specific to the part of the brain affected. Lesion size is correlated with severity, recovery, and comprehension. Brain injuries often create impairment or disability that can vary greatly in severity. Studies show there is a correlation between brain lesion and language, speech, and category-specific disorders. Wernickes aphasia is associated with anomia, unknowingly making up words (neologisms), and problems with comprehension. The symptoms of Wernickes aphasia are caused by damage to the posterior section of the superior temporal gyrus.Damage to the Brocas area typically produces symptoms like omitting functional words (agrammatism), sound production changes, dyslexia, dysgraphia, and problems with comprehension and production. Brocas aphasia is indicative of damage to the posterior inferior frontal gyrus of the brain.An impairment following damage to a region of the brain does not necessarily imply that the damaged area is wholly responsible for the cognitive process which is impaired, however. For example, in pure alexia, the ability to read is destroyed by a lesion damaging both the left visual field and the connection between the right visual field and the language areas (Brocas area and Wernickes area).