Head Injury
Intracranial Injuries
Blunt Intracranial Injuries
Epidural Hematoma (EDH)
Mechanism: usualy associated with basilar skull fracture Þ laceration of middle meningeal artery (MMA) near foramen spinosum
Þ underlying brain is not usually damaged therefore good outcome
Head CT: high attenuation extra-axial; Biconvex/lens-shape; Usually does not cross suture lines
- Located at point of impact (coup site) (coup describes a lesion at the side of impact; contra-coup describes a lesion on the opposite side of the brain from the brain sliding into the opposite side of the skull)
Treatment: Surgical Evacuation
- usually emergent, large exposure, necessary to identify and prevent further bleeding from the MMA, tack up dura
Subdural Hematoma (SDH)
Mechanism: bridging cortical veins (connrect brain to sinus) torn through rotatory movement; commonly associated with contusions, intracerebral hematoma, diffuse edema, subarachnoid hemorrhage; outcome much worse than EDH
Head CT: high attenuation extra-axial; concave shape; crosses suture lines
- located opposite point of impact (contra-coup)
Treatment: Surgical Evacuation
- large exposure, usually dont find active bleeding, underlying brain often swollen, place intracranial pressure (ICP) monitor
Contusion/intracerebral hematoma
Mechanism: brain scrapes over irregular surfaces of skull base
Head CT: high attenuation intra-axial; contra-coup; enlarge over first 48 hours
Treatment: surgical evacuation: debride nonviable brain, enter hematoma cavity and remove clot, place ICP monitor
Diffuse Axonal Injury (DAI)
Head CT: punctate hemorrhage, axonal swelling within white matter; corpus callosum and brainstem often disrupted
Treatment: medical management
Subarachnoid Hemorrhage (SAH)
Head CT: high attenuation following sulci and cisterns; in isolation is a minor injury, no surgery; risk of vasopasm if severe
Diffuse Cerebral Edema
Head CT: loss of grey/white differentiation; obliteration of sulci, cisterns
Treatment: medical management; rarely decompressive craniotomy
Penetrating Intracranial Injuries surgical removal of foreign object
- Gunshot wound
: no treatment if poor exam, bihemispheric injury; debridement of scalp, brain; usually do not attempt retrieval of bullet fragments
Skull Fractures
most dont require surgery
- Types
: basilar, linear, suture diastasis, depressed, open sinus
- Indications for surgery
: depressed; involving frontal sinus; open, compound; or associated with surgical intracranial injury
- Pneumocephalus
air within the cranium
Þ high FiO2; Flat in bed; tension pneumocephalus can require surgery
Herniation Syndromes
Uncal: ipsilateral CN III palsy (mydriasis) hemiparesis (UMN symptoms) contra > ipsilateral (Kernohans Phenomenon)
Central (transtentorial) rapid of loss of conciousness; bilateral signs; small pupils common
Subfalcine cingulate gyrus can herniate through the falx cerebri; usually seen on CT
Tonsillar Medullary Compression Syndrome: respiration abnormalities
Transcranial can be iatrogenic
Diagnostic Evaluation
- Resuscitate: airway, breathing, circulation
- Rapid neurologic examination: level of conciousness (Glascow Coma Scale,below), cranial nerves, motor asymmetry
- Physical exam on Head
- site of impact: soft tissue swelling; laceration, bony step-off, penetrating wound
- basilar skull fracture: Battles sign(ecchymoses behind ear),raccoon eyes(ecchymoses around eyes), hemotympanum
- Physical exam of the remainder of the body
- Glascow coma scale (GCS)
- Eyes
(1-4) open:
- 4 Spontaneously
- 3 To voice
- 2 To pain
- 1: none
- Verbal
(1-5):
- 5 oriented
- 4 confused but speaks sentences
- 3 Inappropriate words
- 2 Incomprehensible sounds
- 1 Nonverbal
- Motor
(1-6):
- 6 Follows commands
- 5 Localizes pain
- 4 Complex flexion
- 3 Flexor posturing
- 2 Extensor posturing
- 1 No movement
- Classification
- Mild: 13-15
- Moderate: 9-12
- Severe:
< 8