🧠 TRAUMATIC BRAIN INJURY (TBI) — COMPLETE NOTES

Traumatic Brain Injury (TBI)\n\n

An injury to the brain caused by mechanical force, which can result from various incidents such as falls, motor vehicle accidents, or sports-related impacts. TBIs can be classified as mild, moderate, or severe based on the extent of damage to brain tissue.

Primary Injury\n\n

The initial damage that occurs at the moment of trauma, resulting from direct impact and mechanical forces. This can include brain tissue damage, blood vessel rupture, skull fracture, and other immediate structural disruptions to the brain.

Secondary Injury\n\n

A cascade of cellular and biochemical processes that occur following the primary injury. Secondary injuries arise from mechanisms such as inflammation, ischemia, and oxidative stress, which can exacerbate the initial damage and hinder recovery.

Aetiology\n\n

The study of causes, specifically referring to the mechanical causes of traumatic brain injuries. Common causes include falls, motor vehicle accidents, assaults, sports injuries, and penetrating head injuries.

Epidural Haematoma (EDH)\n\n

A collection of blood that forms between the skull and the dura mater, often resulting from a laceration of an artery due to traumatic force. This condition is characterized by a rapid increase in intracranial pressure and typically requires urgent medical intervention.

Subdural Haematoma (SDH)\n\n

A collection of blood that occurs between the dura mater and the arachnoid mater, usually resulting from tearing of veins due to sudden acceleration-deceleration forces. SDH can manifest acutely or chronically, with varying implications for treatment and prognosis.

Lucid Interval\n\n

A phenomenon commonly associated with epidural hematoma, where a patient loses consciousness immediately following trauma, regains composure, and then suddenly deteriorates neurologically. This interval can be deceptive, as it can mislead both the patient and medical professionals regarding the severity of the injury.

CT Scan Finding for EDH\n\n

On a CT scan, an epidural hematoma typically appears as a biconvex (lens-shaped) hyperdense area, indicating arterial bleeding. This distinct shape is a critical factor in diagnosis and management.

CT Scan Finding for SDH\n\n

A subdural hematoma on a CT scan presents as a crescent-shaped hyperdense area that conforms to the contours of the brain. This finding is crucial in differentiating SDH from other types of hematomas.

Acute SDH\n\n

Occurs due to severe, often blunt head trauma, leading to rapid hematoma formation and symptoms such as headache, confusion, and loss of consciousness within a short time frame. Acute SDH is associated with a high risk of mortality if not promptly addressed.

Chronic SDH\n\n

Typically develops due to minor head trauma, particularly in older adults, leading to a slow accumulation of blood. Symptoms may not manifest for weeks or months and can include headaches, altered mental status, and neurological deficits.

Epidural vs Subdural\n\n

Epidural hematomas often present as emergencies due to fast-acting arterial bleeding and can lead to rapid deterioration of neurological function, whereas subdural hematomas tend to develop more slowly, involving venous bleeding and are frequently seen in the elderly.