head trauma Flashcards
anatomy and physiology
● Rigid, nonexpansile skull filled with
brain, CSF, and blood
● Cerebral blood flow (CBF) usually
autoregulated
● Autoregulatory compensation
disrupted by brain injury
● Mass effect of intracranial hemorrhage
monro-kellie doctrine
3 types:
- normal state - normal icp
- compensated state - ICP normal
- Decompensated state - ICP elevated
monro kellie doctrine diagram
volume pressure curve
intracrainal pressure
10mmHg = normal
>20 mm Hg = Abnormal
>40 mm Hg = Severe
cerebral perfusion pressure?
Mean Artrial Pressure (MAP) - ICP = CPP
autoregulation?
If autoregulation is intact, CBF is
maintained constant between a mean
BP of 50 to 60 mm Hg.
● In moderate or severe brain injury,
autoregulation is impaired so CBF
varies with mean BP.
● The injured brain is more vulnerable to
episodes of hypotension, causing
secondary brain injury
types of skull fractures?
- Vault Fractures
a) Fissure (linear) fractures
b) Depressed fractures - Base Fractures
Anterior, middle, posterior fossa.
depressed fractures?
Types:
1) Simple (closed)
Skin intact
Common in children
Overlying hematoma
Cerebral compression is rare
2) Compound (open)
Scalp wound and bleeding
CSF leak or protruded brain parenchyma
Infection
complications?
- Intracerebral hematoma
- Injury to venous sinuses
- Dural tear and infection
- Epilepsy
- Cosmetic
treatment
- Simple depressed fracture
a) Conservative
b) Surgical (elevation of depressed fracture) in case of:
i. Large depressed segment more than one inch
ii. Depression more than thickness of skull
iii. Suspected dural laceration
iv. Deficit related to underlying brain compression by depressed
bone
v. Cosmetic deformity
vi. Fracture overlying air sinus - Compound depressed fracture
Antibiotics are given and the wound is explored in the operating
theatre. Foreign bodies are removed, bone fragments are elevated
and any dural tear is closed.
fracture base?
- Fracture is usually compound (open to exterior)
leading to escape of blood, CSF, or brain matter. Risk
of infection is present- meningitis - Cranial nerve injury may occur due to laceration,
compression by blood clot, scar or callus - Associated brain injury depends on the fossa involved.
anterior crainal fossa injury
3 signs
- rhinorrhoea
- bilateral periorbital haematoma
- subconjuncitval haemorrhage
- Escape of intracranial contents (blood, CSF &
brain) - Cranial nerve injury: 1st-3rd cranial nerves
- Associated brain injury: concussion is usually
severe
middle crainal fossa?
- Escape of intracranial contents
a. Blood: Epistaxis. Blood will clot unless it is mixed with
CSF. Post auricular ecchymosis (Battle’s sign)
b. CSF escape through ears (otorrhea) mixed with blood
c. Surgical emphysema of scalp around and behind the
ear (fractures involving the mastoid antrum and air cells) - Cranial nerve injury from 5 to 8
- Associated brain damage often severe
blood or SF leaking through a torn tympanic membrane must be diffeentiated rom a laceration of external meatus
Battle’s sign: brusing over the mastoid may take 24-48 hours to develop.
posterior cranail fossa?
1.Escape of fluid rarely occurs. Boggy swelling
(haematoma) or discolouration in the
suboccipital area.
2. Cranial nerve injury 9,10,11 may be damaged at
foramen magnum. Hypoglossal usually escapes
Occipital haematoma may irritate upper cervical
nerves- neck rigidity & head retraction
3. Associated brain injury: severe coma due to
injury of pons & medulla. Subtentorial herniation
may lead to bulbar compression and tonsillar
herniation. Death commonly occurs
defining brain injuries by morphology
Focal
● Epidural (extradural)
● Subdural
● Intracerebral
By Morphology – Brain Injuries
Diffuse
● Concussion
● Multiple contusions
● Hypoxic / ischemic injury
glasgo coma scale
Has limitations in chronic conditions and those
with focal abnormalities
locked in syndrome from Pontine infarcts
The use of numbers is not helpful in
communication
Better to describe briefly the assessment.
Opening eyes to pain, no verbal response and flexing to
pain is better than GCS of ????
extradural hematoma?
● Associated with skull fracture
● Classic: middle meningeal artery tear
● Lenticular / biconvex
● Lucid interval
● Can be rapidly fatal
● Early evacuation essential
anatomy of muiddle meningeal artery?
It is a branch of maxillary artery in the
infratemporal fossa.
Middle cranial fossaforamen spinosum (above
the mid zygomatic arch point), it divides into:
a) Anterior branch which passes upwards and
forwards in a bony canal at the pterion. It
overlies the motor cortex (convulsions)
b) Posterior branch passes backwards, grooves
the temporal bone and is overlying the superior
temporal gyrus
concussion stage?
Loss of consciousness starts
synchronuous with trauma
Pulse: rapid & weak. Temperature
subnormal, respiration shallow and slow
Pupils
B.P. low
Reflexes lost, sphincters relaxed
Cold clammy skin
Duration from few minutes to few hours
lucid interval?
The patient regains consciousness and BP
rises enough to cause bleeding from the
injured vessels
In severe trauma patient may not regain
consciousness (no lucid interval) and
passes directly to compression stage
Lucid interval is longer if bleeding is due to
a venous cause
compression stage
(uncal herniation
=tentorial herniation)
i. Consciousness gradually
deterioratesdrowsiness
/semicoma then coma
ii. Contralateral hemiparesis
due to pressure on the
ipsilateral crus
Later ipsilateral hemiparesis
also occurs
iii. The pupils show
characteristic changes
ipsilateral then
contralateral irritation
followed by paralysis of
the 3rd nerve
mass and 3 nerve palsy
eye signs
treatment
Urgent evacuation of the
haematoma and dealing
with the bleeder must be
done before late
compression occurs
subdural haematoma?
Aetiology:
Severe head injury leading to:
a) Rupture of a large cortical vein as it crosses
the subdural space to reach the fixed dural
sinus
b) Cortical lacerationhaemorrhage in subdural
space
subdural hematoma?
● Venous tear / brain laceration
● Covers cerebral surface
● Morbidity / mortality due to
underlying brain injury
● Rapid surgical evacuation
recommended, especially if > 5 mm
shift of midline
extra vs sub dural hematoma
chronic subdural hematoma?
Aetiology:
A trivial blow on the head
which may pass unnoticed
The patient is predisposed by
1. Shrunken brain (old age)
2. Patient at risk of fall
(Hemiplegic, Alcoholic,
Seizures)
3. Coagulation problems:
anticoagulants, liver disease
treatment for chronic subdural hematom
burr holes
craniotomy
Craniotomy – a section of your skull is temporarily removed to allow the surgeon access and remove the haematoma
intracerebral hematoma
● Coup / contracoup injuries
● Most common: frontal / temporal lobes
● CT changes usually progressive
● Most conscious patients: no operation
diffuse head injury
goes throughout the whole of brain
mild brain injury
● GCS score = 13 – 15
● History
● Exclude systemic injuries
● Neurologic exam
● X-rays as indicated
● Alcohol / drug screens as indicated
● Liberal use of head CT
moderate brain injury
● GCS score = 9 – 12
● Initial evaluation same as for mild injury
● CT scan for all
● Admit and observe
● Frequent neurologic exams
● Repeat CT scan
● Deterioration: Manage as severe head
injury
severe brain injury?
● GCS score = 3 – 8
● Evaluate and resuscitate
● Intubate for airway protection
● Focused neurologic exam
● Frequent reevaluation
● Identify associated injuries
when to give ct
those with battle sign
or
high risk
● GCS score still < 15 two hours after injury
● Neurologic deficit
● Open skull fracture
● Sign of basal skull fracture
● Extremes of age
or moderate risk
● “Dangerous mechanism”
● Retrograde amnesia > 30 minutes in
duration
● Severe headache
● Vomiting > 2 episodes
how to manage
● ABCDE
● Minimize secondary brain injury
● Administer oxygen
● Maintain adequate ventilation
● Maintain blood pressure
(systolic > 90 mm Hg)
● Controlled ventilation
● Goal: Paco2 at 35 mm Hg
● Intravenous fluids
● Euvolemia
● Isotonic
● Consult with neurosurgeon
● Mannitol
● Use with signs of tentorial herniation
● Dose: 0.25 to 1.0 g / kg IV bolus
Mannitol
Osmotic Diuretic
Positive inotrope
Free radial scavenger
Use with signs of tentorial herniation
Dose: 1.0 g / kg IV bolus
Consult with neurosurgeon
● Other medications
● Anticonvulsants
● Sedation
● Paralytics
surgical managment
● Scalp Wounds
● Possible site of major blood loss
● Direct pressure to control bleeding
● Occasional temporary closure
scalp injuries
- Skin
- Connective tissue (b.v.
and nerves) - Aponeurosis (galea
aponeurotica) - Loose areolar tissue
- Pericranium (skull
periosteum firmly
attached at the sutures)
scalp hematomas
- Subcutanous
- Subgaleal
- Subperiosteal (Cephalhematoma)
manage scalp hematomas
surgicaly
● Intracranial Mass Lesion
● Can be life-threatening if expanding rapidly
● Immediate neurosurgical consult
● Hyperventilation / mannitol
● Damage control craniotomy: transfer to
neurosurgeon (rural / austere areas)
how to diagnose brain death
