ABPN Brain Injury Medicine key terms

Pattern of traumatic brain injury in which impact produces focal damage at the site of the blow and an opposite-side injury as the brain strikes the inner skull. Contusions most often affect the frontal and temporal poles.

Widespread shearing of white matter tracts from angular acceleration and deceleration forces, producing axonal swelling and disconnection. It is a major cause of prolonged coma and poor outcome after severe trauma.

Blood or cerebrospinal fluid proteins released when injured axons break down, such as neurofilament light, GFAP, and tau. They help grade injury severity, predict outcome, and detect injury in patients with normal imaging.

A neurodegenerative tauopathy linked to repetitive head impacts, defined neuropathologically by perivascular tau deposits at the depths of cortical sulci. Clinical features include behavioral change, cognitive decline, and parkinsonism.

The intrinsic ability of cerebral vessels to keep blood flow relatively constant despite changes in systemic blood pressure. It is often impaired after severe injury, making perfusion pressure-dependent flow and secondary injury more likely.

Principle stating that the skull is a rigid container holding brain, blood, and cerebrospinal fluid at constant total volume. An increase in one compartment must be offset by a decrease in others or pressure rises.

The pressure within the cranial vault, normally below about 15 mm Hg in adults. Sustained elevation reduces cerebral perfusion and can cause herniation, so it is monitored and treated in severe injury.

Mean arterial pressure minus intracranial pressure; the driving pressure for cerebral blood flow. Targets are typically 60 to 70 mm Hg in adults, balancing ischemia risk against pressure-related edema.

A 3-to-15 point score summing eye, verbal, and motor responses used to grade level of consciousness after brain injury. Scores of 13 to 15 indicate mild, 9 to 12 moderate, and 3 to 8 severe injury.

A state of unarousable unresponsiveness following brain trauma, usually reflecting dysfunction of the reticular activating system or widespread hemispheric injury. Duration and depth help predict outcome.

Persistent states of impaired awareness and wakefulness after severe brain injury, including coma, vegetative or unresponsive wakefulness state, and minimally conscious state. Distinguishing them requires structured serial behavioral assessment.

The interval after injury during which memory and orientation are disrupted, often measured with the Galveston Orientation and Amnesia Test. Its duration is a strong predictor of functional outcome.

A period of disorientation, agitation, and fluctuating attention that commonly follows emergence from coma. It reflects disturbed cerebral metabolism and requires environmental and behavioral management.

Excessive motor activity, aggression, and disinhibition arising during recovery, often with restlessness and resistance to care. It usually improves over weeks and is managed with environmental structure and cautious medication.

Enlargement of the ventricles with raised or normal pressure after brain injury, causing decline in cognition, gait, and continence. It may respond to shunt placement when symptoms and imaging are consistent.

Episodes of tachycardia, hypertension, fever, sweating, and posturing after severe brain injury, driven by disordered autonomic control. It is a diagnosis of exclusion and is managed by avoiding triggers and using modulating drugs.

Velocity-dependent increase in muscle tone with exaggerated stretch reflexes after damage to upper motor neuron pathways. It can impair function and comfort and is treated with positioning, therapy, and medications or chemodenervation.

Formation of mature bone in soft tissue, often around large joints after severe brain injury, causing pain and reduced range of motion. It appears weeks to months after injury and is confirmed by imaging.

Recurrent unprovoked seizures beginning more than one week after brain injury, reflecting epileptogenesis in injured cortex. Risk rises with penetrating injury, hemorrhage, and prolonged post-traumatic amnesia.

Short-term anticonvulsant treatment given after severe traumatic brain injury to prevent early seizures, generally for about one week. It does not prevent later post-traumatic epilepsy.

Rapid, often fatal brain swelling occurring when a second head impact happens before recovery from an earlier concussion. Return-to-play protocols aim to prevent it by withholding activity until symptoms resolve.

A mild traumatic brain injury from biomechanical forces to the head or body, producing transient neurologic symptoms without structural lesions on standard imaging. Management centers on rest, gradual return, and symptom monitoring.

Cumulative subconcussive and concussive blows to the head over a career or lifetime. It is associated with long-term neuropathology and is a focus of prevention and monitoring in contact sports.

An eight-level descriptive scale of cognitive and behavioral recovery after brain injury, from no response through purposeful appropriate behavior. It guides rehabilitation planning and communication among teams.

An 18-item instrument scoring self-care, mobility, communication, and social cognition on a seven-point scale. It is widely used to track rehabilitation progress and predict discharge needs.

Standardized testing of attention, memory, language, visuospatial skills, and executive function to characterize cognitive strengths and deficits after injury. Results inform diagnosis, rehabilitation, and capacity decisions.

Impaired planning, initiation, self-monitoring, and behavioral control after frontal and subcortical injury. It often limits independence more than memory or motor deficits and may be missed on brief screening.

Irritability, impulsivity, mood swings, and poor frustration tolerance arising from injury to frontal and limbic circuits. It is managed with structured environments, psychotherapy, and careful pharmacologic treatment.

Intrusion, avoidance, negative mood, and hyperarousal symptoms developing after a traumatic event, including injury-related trauma. It frequently coexists with mild brain injury and complicates recovery.

Reduced goal-directed behavior, initiative, and emotional engagement not explained by depression or sedation. It is common after frontal and subcortical injury and can be mistaken for depression or noncompliance.

An eight-item measure of arousal, awareness, cognitive ability for self-care, dependence, and employability after brain injury. It tracks recovery across the continuum from coma to community reentry.

An eight-category rating of global outcome after brain injury, from death through upper good recovery. It is a standard endpoint in clinical trials and outcome research.

Brain damage from inadequate oxygen or blood flow, as after cardiac arrest, affecting metabolically demanding regions such as hippocampus and cortex. Outcomes range from full recovery to persistent disorders of consciousness.

Surgical removal of part of the skull to allow a swollen brain to expand and reduce intracranial pressure. It lowers mortality in selected severe cases but may increase survival with severe disability.

Controlled cooling of the body after cardiac arrest or severe brain injury to limit secondary neuronal damage. Evidence supports its use after cardiac arrest, while benefit in traumatic brain injury remains uncertain.

The ethical and legal requirement that patients understand, appreciate, reason about, and communicate a treatment choice. When injury impairs capacity, surrogate decision-making follows advance directives or best-interest standards.

A court-ordered arrangement appointing someone to make personal or financial decisions for a person judged unable to do so. It should be the least restrictive option and is reviewed periodically.

Structured assessments of fitness for employment and motor vehicle operation after injury, weighing cognition, seizure risk, and vision. Recommendations often require formal testing and may be subject to legal reporting rules.

Population and individual strategies such as helmet use, seat belts, fall prevention, and traffic safety enforcement that reduce injury incidence and severity. Prevention is the most effective approach to lowering burden.