Path 370 - W8: Ch.44 Brain Injury

What is the Glascow Coma Scale (GCS)?

*Standardized tool for assessing LOC in numeric form. *Numeric scores based on the patients eye, verbal, and motor reactions. Mild (12 to 15). Moderate (9 to 12). Severe (1 to 8).

Due to ischemia and hypoxia, what cellular operations change that cause neuron death?

1. Anaerobic metabolism. Lactic acid increase acidity that destroy cell membrane. 2. Deterioration of ion gradients. Insufficient ions prevent synapses and causes free radicals.

What is a subarachnoid hemorrhage?

1. Blood between arachnoid membrane and the pia mater. 2. Involves bridging veins that pass through subarachnoid space. 3. Typical result of arterial problems like cerebral aneurysms or arteriovenous malformations.

What is a subdural hematoma?

1. Blood between dura and outer layer of arachnoid membrane. 2. Involves bridging veins with symptoms developing slowly. 3. Typical result of head trauma and common with elderly and alcoholics. Surgical removal of tissue and clot for worse cases.

What is a epidural hematoma?

1. Blood between the dura and the skull. 2. Involves arterial injury that's why it develops instantly and show symptoms. 3. Minor injury but worst cases might need surgery.

The volume of the cranium is composed of what three components?

1. Brain Tissue. 2. Cerebrospinal Fluid. 3. Blood (0 to 15 mm Hg).

During brain injury, excess glutamate causes nearby neurons to do what?

1. Calcium overload leading to cytotoxic edema / swelling. 2. Increase nitric oxide production in which nitrogen become free radicals to cause damage.

What are the three types of intracranial hematomas?

1. Epidural 2. Subdural 3. Subarachnoid

What are common s/s of ICP?

1. Headache, vomiting, and altered consciousness. 2. Blurry vision, and edema of the optic disk. 3. Altered respiratory, unresponsive to stimulation, unable to move, verbalize, or open the eyes.

What three issues can result to increased intracranial pressure (ICP)?

1. Increased brain tissue (lesions): tumor, infection, edema. 2. Increased CSF. 3. Increased blood volume.

How to manage brain injury?

1. Surgery. 2. Medication. 3. Stabilize cerebral pressure. Must be greater than 60 mm Hg. 4. Remove lesion or CSF. 5. Monitor cerebral oxygenation.

How long does the brain have before irreversible brain damage from oxygen deprivation occurs?

5 to 10 minutes

What is primary TBI?

A traumatic brain injury due to blow or injury directly to the head. Focal is a direct trauma. Polar is front or rear impact trauma. Diffused is wide spread / axonal / coma.

What is a complete loss of level of consciousness?

Coma

Is glutamate an excitatory or inhibitory amino acid?

Excitatory - if normal levels, it is important for learning and memory.

During brain injury, what is produced excessively because of impaired membrane integrity?

Glutamate (AKA excitotoxin).

Why does glutamate become excessive during brain injury?

Glutamate removal is dependent on energy. But without ATP due to ischemia and hypoxia, it doesn't get removed.

What brain injury is a protrusion of brain tissue through an opening in the supporting dura of the brain?

Herniation.

What are the two causes of brain injury?

Ischemia and hypoxia. Hypoxia follows ischemia.

How does ischemia and hypoxia cause brain injury?

Lack of oxygen cuts the ability of neurons to generate ATP needed for cell operation.

What is the most sensitive indicator of altered brain function?

Level of Consciousness (LOC)

What is a concussion TBI?

Mild traumatic brain injury with NO TISSUE INJURY. Most common injury encountered by military personnel and athletes - can last 30 minutes but no evidence of brain damage.

What is a contusion TBI?

Mild traumatic brain injury with TISSUE INJURY such as lacerations, bruising, necrosis.

How does reperfusion injury occur during brain injury?

Oxygen reentering the cell can become free radicals (hydroxyl, superoxide, peroxide).

What is secondary brain injury?

Refers to the "after effects" of the primary injury; it includes abnormal processes such as cerebral edema, intracranial hemorrhage, increased ICP, cerebral ischemia and hypoxia, and infection.

What are four types of brain herniation?

STUT! 1. Subfalcine (most common) 2. Tentorial 3. Uncal 4. Tonsillar

What are some treatments to secondary brain injury?

Standard: 1. Cardiopulmonary stabilization. 2. Radiology to check if surgery needed. 3. Maintain normal body temp. 4. Maintain normal PaCO2. 5. Maintain normal glucose levels. 6. Maintain normal blood volume. ICP Issues: 1. Mild: mannitol and sedation. 2. Severe: diuretics, saline. Open Headed Injury: 1. Prophylactic antibiotics. Skull Fractures: 1. Prevent CSF seeping out. 2. Treat black eyes. 3. Treat bruising of ears.

What is TBI?

Traumatic Brain Injury.

What is oculovestibular reflex?

•Impaired reflex implies brainstem dysfunction. •Doll's-eyes maneuver entails rotating the patient's head from side to side. Normally, eyes turn in opposite direction of the head rotation. •Cold caloric: inject cold water into ear and normally eyes deviate toward the side of irritation.

What is the pupil reflex?

•Indicates the function of the brainstem and cranial nerves (CN) II and III •Changes in size, shape, and reactivity of the pupil as early indicator of ICP and possible brain herniation.