etiology head injury

8/6/2019 ETIOLOGY Head Injury

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ETIOLOGY:

The majority of head injuries occur in young adults as a result of sports injuries and accidents

involving cars/motorcycle. In many of these accidents, excessive alcohol intake is a contributing

factor. Unfortunately, a high blood Alcohol level can impede neurologic assessment by making

the signs of injury.

Alcohol, because of its dehydrating effects, tends to delay the onset of cerebral edema and

elevation of ICP, but there may be greater increased ICP at a later time. Other systemic injuries,

such as a chest injury/shock, can have the same effect.

Traumatic brain injury (TBI), a form of acquired brain injury, occurs when a sudden trauma

causes damage to the brain. TBI can result when the head suddenly and violently hits an object,

or when an object pierces the skull and enters brain tissue. Symptoms of a TBI can be mild,

moderate, or severe, depending on the extent of the damage to the brain.

CLINICAL MANIFESTATION:

MILD

may remain conscious or may experience a loss of consciousness for a few seconds or

minutes.

Other symptoms of mild TBI include:

headache

Confusion

Lightheadednessdizziness,

blurred vision or tired eyes

ringing in the ears

bad taste in the mouth,

fatigue or lethargy

a change in sleep patterns

behavioral or mood changes

and trouble with memory, concentration, attention, or thinking.

MODERATE TO SEVERE

may show these same symptoms, but may also have a :

headache that gets worse or does not go away

repeated vomiting or nausea

convulsions or seizures

an inability to awaken from sleep



dilation of one or both pupils of the eyes

slurred speech

weakness or numbness in the extremities

loss of coordination,

and increased confusion, restlessness, or agitation.

CAUSES:

The five most common causes of head injuries or TBI (Traumatic Brain Injury) are:

y Car Accidents (passenger and pedestrian)

y Bicycle /Motorcycle Accidents

y Falls (especially kids and the elderly)

y Sports

y Acts of Violence/Assault

Some head injuries result in prolonged or nonreversible brain damage. This can occur as a

result of bleeding inside the brain or forces that damage the brain directly. These more serious

head injuries may cause:

y Coma

y Chronic headaches

y Loss of or change in sensation, hearing, vision, taste, or smell

y Paralysis

y Seizures

y Speech and language problems

HEAD INJURY OVERVIEW

Head injury is a general term used to describe any trauma to the head, and most

specifically to the brain itself.

TYPES OF HEAD INJURY:

1. CONCUSSION: reversible interference and brain function, usually resulting from a mild blow

to the head, which causes sudden excessive movement of the brain, disrupting neurologic

function and leading to loss of consciousness.

2. CONTUSSION: is a bruising tissue with rupture of small blood vessels and edema that

usually results from a blunt blow to the head.



3. SKULL FRACTURE: A skull fracture is a break in the bone surrounding the brain and other

structures within the skull.

Linear skull fracture: A common injury, especially in children. A linear skull fracture

is a simple break in the skull that follows a relatively straight line. It can occur after

seemingly minor head injuries (falls, blows such as being struck by a rock, stick, or

other object; or from motor vehicle accidents).

Depressed skull fractures: These are common after forceful impact by blunt

objects-most commonly, hammers, rocks, or other heavy but fairly small objects.

These injuries cause "dents" in the skull bone .

Basilar skull fracture: A fracture of the bones that form the base (floor) of the skull

and results from severe blunt head trauma of significant force.

Compound fractures: Involve trauma to the environment and is likely to be

severely damaged because bone fragments may penetrate the tissue and the risk

of infection is high. Comminuted fractures: consist of several fracture lines but may not be

complicated.

4. INTRACRANIAL (INSIDE THE SKULL) HEMORRHAGE (BLEEDING)

Head/brain:

Subgaleal hematoma between the galea aponeurosis and periosteum

Cephalohematoma between the periosteum and skull

Epidural hematoma between the skull and dura mater

Subdural hematoma between the dura mater and arachnoid mater

Subarachnoid hematoma between the arachnoid mater and pia

mater (the subarachnoid space)

Othematoma between the skin and the layers of cartilage of the ear

5. OPENED HEAD INJURIES: are those involving fractures/penetration of the brain by sharp

objects.

6. CLOSED HEAD INJURIES: occurs when the skull is not fractured in the injury, but the brain

tissue is injured and blood vessels may be ruptured by the force exerted against the skull.

7. CONTRECOUP INJURY: occurs when an area of the brain contralateral to the site of direct

damage in injured as the brain bounces off the skull.



DIAGNOSTIC STUDIES

1. CT scan (with/without contrast): Screening image of choice in acute brain injury. Identifies

space-occupying lesions, hemorrhage, skull fractures, brain tissue shift.

2. MRI: Uses similar to those of CT scan but more sensitive than CT for detecting cerebral

trauma, determining neurologic deficits not explained by CT, evaluating prolonged interval of

disturbed consciousness, defining evidence of previous trauma superimposed on acute trauma.

3. Cerebral angiography: Demonstrates cerebral circulatory anomalies, e.g., brain tissue shifts

secondary to edema, hemorrhage, trauma.

4. X-rays: Detect changes in bony structure (fractures), shifts of midline structures

(bleeding/edema), bone fragments.

5. PET/SPECT tomography: Detects changes in metabolic activity in the brain and may be used

for differentiation of head injuries. (These procedures are not in widespread clinical use, but are

more often used for research.)

6. Audiometry, otology, and vestibular function tests: Diagnostic procedures that identifyhearing loss, reasons for balance problems, and/or eighth cranial nerve dysfunction.

7. Lumbar puncture and CSF analysis: May be performed in patient with suspected or known

increased intracranial pressure when CT or MRI is not diagnostic. Generally contraindicated in

acute trauma.

8. ABGs: Determines presence of ventilation or oxygenation problems that may

exacerbate/increase intracranial pressure.

9. Serum chemistry/electrolytes: May reveal imbalances that contribute to increased

intracranial pressure (ICP)/changes in mentation.

10. Toxicology screen: Detects drugs that may be responsible for/potentiate loss of

consciousness.

NURSING DIAGNOSIS:

Disturbed thought processes related to brain damage, confusion, or inability to follow

instructions

Impaired physical mobility related to hemiparesis, loss of balance and coordination,

spasticity, and brain injury

Impaired verbal communication related to brain damage

Ineffective airway clearance and impaired gas exchange related to brain injury

Risk for impaired skin integrity related to immobility

Risk for imbalanced body temperature related to damaged temperature-regulating

mechanisms in the brain

Interrupted family processes related to unresponsiveness of patient, unpredictability of

outcome, prolonged recovery period, and the patients residual physical disability and

emotional deficit

Deficient fluid volume related to decreased LOC and hormonal dysfunction



TREATMENT

Anyone with signs of moderate or severe TBI should receive medical attention as soon as

possible. Because little can be done to reverse the initial brain damage caused by trauma,

medical personnel try to stabilize an individual with TBI and focus on preventing further

injury. Primary concerns include insuring proper oxygen supply to the brain and the rest of the body, maintaining adequate blood flow, and controlling blood pressure. Imaging tests

help in determining the diagnosis and prognosis of a TBI patient.

Patients with mild to moderate injuries may receive skull and neck X-rays to check for

bone fractures or spinal instability. For moderate to severe cases, the imaging test is a

computed tomography (CT) scan.

Moderately to severely injured patients receive rehabilitation that involves individually

tailored treatment programs in the areas of physical therapy, occupational therapy,

speech/language therapy, physiatrist (physical medicine), psychology/psychiatry, and

social support.

PROGNOSIS

The potential for improvement after TBI can be unpredictable. Progress can be painfully slow

and the patient may never be the same as he was before the injury. As the brain heals,

personality and behavior may change and the patient may face new issues and challenges.



Picture of the areas of the brain subject to injury

etiology head injury

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