Traumatic brain<unk>  is defined as damage to the brain resulting from external mechanical force, such as rapid acceleration or deceleration, impact, blast waves, or penetration by a projectile. Brain function is temporarily or permanently impaired and structural damage may or may not be detectable with current technology. TBI is one of two subsets of acquired brain<unk>  (brain damage that occur after birth); the other subset is non-traumatic brain<unk> , which does not involve external mechanical force (examples include stroke and infection). All traumatic brain<unk> es are<unk> <unk> es, but the latter term may also refer to<unk>  to other parts of the<unk> . However, the terms<unk><unk>  and brain<unk>  are often used interchangeably. Similarly, brain<unk> es fall under the classification of central nervous system<unk> es and neurotrauma. In neuropsychology research literature, in general the term "traumatic brain<unk> " is used to refer to non-penetrating traumatic brain<unk> es. TBI is usually classified based on severity, anatomical features of the<unk> , and the mechanism (the causative forces). Mechanism-related classification divides TBI into closed and penetrating<unk><unk> . A closed (also called nonpenetrating, or blunt)<unk>  occurs when the brain is not exposed. A penetrating, or open,<unk><unk>  occurs when an object pierces the skull and breaches the dura mater, the outermost membrane surrounding the brain. Severity + Severity of traumatic brain<unk>  GCS PTA LOC Mild 13–15 day 0–30 minutes Moderate 9–12 >1 to days >30 min to 7 days >24 hours Brain<unk> es can be classified into mild, moderate, and severe categories. The Glasgow Coma Scale (GCS), the most commonly used system for classifying TBI severity, grades a person's level of consciousness on a scale of 3–15 based on verbal, motor, and eye-opening reactions to stimuli. In general, it is agreed that a TBI with a GCS of 13 or above is mild, 9–12 is moderate, and 8 or below is severe. Similar systems exist for young children. However, the GCS grading system has limited ability to predict outcomes. Because of this, other classification systems such as the one shown in the table are also used to help determine severity. A current model developed by the Department of Defense and Department of Veterans Affairs uses all three criteria of GCS after resuscitation, duration of post-traumatic amnesia (PTA), and loss of consciousness (LOC). It also has been proposed to use changes that are visible on neuroimaging, such as swelling, focal lesions, or diffuse<unk>  as method of classification. Grading scales also exist to classify the severity of mild TBI, commonly called concussion; these use duration of LOC, PTA, and other concussion symptoms. Pathological features CT scan Spread of the subdural hematoma (single arrows), midline shift (double arrows) Systems also exist to classify TBI by its pathological features. Lesions can be extra-axial, (occurring within the skull but outside of the brain) or intra-axial (occurring within the brain tissue). Damage from TBI can be focal or diffuse, confined to specific areas or distributed in a more general manner, respectively. However, it is common for both<unk>  of<unk>  to exist in a given case. Diffuse<unk>  manifests with little apparent damage in neuroimaging studies, but lesions can be seen with microscopy techniques post-mortem, and in the early 2000s, researchers discovered that diffusion tensor imaging (DTI), a way of processing MRI images that shows white matter tracts, was an effective tool for displaying the extent of diffuse axonal<unk> .<unk>  of<unk> es considered diffuse include edema (swelling), concussion and diffuse axonal<unk> , which is widespread damage to axons including white matter tracts and projections to the cortex. Focal<unk> es often produce symptoms related to the functions of the damaged area. Research shows that the most common areas to have focal lesions in non-penetrating traumatic brain<unk>  are the orbitofrontal cortex (the lower surface of the frontal lobes) and the anterior temporal lobes, areas that are involved in social behavior, emotion regulation, olfaction, and decision-making, hence the common social/emotional and judgment deficits following moderate-severe TBI. Symptoms such as hemiparesis or aphasia can also occur when less commonly affected areas such as motor or language areas are, respectively, damaged. One<unk> of focal<unk> , cerebral laceration, occurs when the tissue is cut or torn. Such tearing is common in orbitofrontal cortex in particular, because of bony protrusions on the interior skull ridge above the eyes. In a similar<unk> , cerebral contusion (bruising of brain tissue), blood is mixed among tissue. In contrast, intracranial hemorrhage involves bleeding that is not mixed with tissue. Hematomas, also focal lesions, are collections of blood in or around the brain that can result from hemorrhage. Intracerebral hemorrhage, with bleeding in the brain tissue itself, is an intra-axial lesion. Extra-axial lesions include epidural hematoma, subdural hematoma, subarachnoid hemorrhage, and intraventricular hemorrhage. Epidural hematoma involves bleeding into the area between the skull and the dura mater, the outermost of the three membranes surrounding the brain. In subdural hematoma, bleeding occurs between the dura and the arachnoid mater. Subarachnoid hemorrhage involves bleeding into the space between the arachnoid membrane and the pia mater. Intraventricular hemorrhage occurs when there is bleeding in the ventricles.
types of Head injury
symptom of Stroke
medical cause of Infection
symptom of Birth defect
History of neurology and neurosurgery
symptom of Cardiovascular disease
symptom of Congenital heart defect
symptom of Subarachnoid hemorrhage