head trauma

Question 1

anatomy and physiology

Answer 1

● 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

Question 2

monro-kellie doctrine

Answer 2

3 types:

1. normal state - normal icp
2. compensated state - ICP normal
3. Decompensated state - ICP elevated

Question 3

monro kellie doctrine diagram

Answer 3

Question 4

volume pressure curve

Answer 4

Question 5

intracrainal pressure

Answer 5

10mmHg = normal

>20 mm Hg = Abnormal

>40 mm Hg = Severe

Question 6

cerebral perfusion pressure?

Answer 6

Mean Artrial Pressure (MAP) - ICP = CPP

Question 7

autoregulation?

Answer 7

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

Question 8

types of skull fractures?

Answer 8

1. Vault Fractures
   a) Fissure (linear) fractures
   b) Depressed fractures
2. Base Fractures
   Anterior, middle, posterior fossa.

Question 9

depressed fractures?

Answer 9

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

Question 10

complications?

Answer 10

1. Intracerebral hematoma
2. Injury to venous sinuses
3. Dural tear and infection
4. Epilepsy
5. Cosmetic

Question 11

treatment

Answer 11

1. 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
2. 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.

Question 12

fracture base?

Answer 12

1. Fracture is usually compound (open to exterior)
   leading to escape of blood, CSF, or brain matter. Risk
   of infection is present- meningitis
2. Cranial nerve injury may occur due to laceration,
   compression by blood clot, scar or callus
3. Associated brain injury depends on the fossa involved.

Question 13

anterior crainal fossa injury

Answer 13

3 signs

1. rhinorrhoea
2. bilateral periorbital haematoma
3. subconjuncitval haemorrhage
4. Escape of intracranial contents (blood, CSF &
   brain)
5. Cranial nerve injury: 1st-3rd cranial nerves
6. Associated brain injury: concussion is usually
   severe

Question 14

middle crainal fossa?

Answer 14

1. 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)
2. Cranial nerve injury from 5 to 8
3. 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.

Question 15

posterior cranail fossa?

Answer 15

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

Question 16

defining brain injuries by morphology

Answer 16

Focal
● Epidural (extradural)
● Subdural
● Intracerebral
By Morphology – Brain Injuries

Diffuse
● Concussion
● Multiple contusions
● Hypoxic / ischemic injury

Question 17

glasgo coma scale

Answer 17

 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 ????

Question 18

extradural hematoma?

Answer 18

● Associated with skull fracture
● Classic: middle meningeal artery tear
● Lenticular / biconvex
● Lucid interval
● Can be rapidly fatal
● Early evacuation essential

Question 19

anatomy of muiddle meningeal artery?

Answer 19

It is a branch of maxillary artery in the
infratemporal fossa.
Middle cranial fossaforamen 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

Question 20

concussion stage?

Answer 20

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

Question 21

lucid interval?

Answer 21

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

Question 22

compression stage

Answer 22

(uncal herniation
=tentorial herniation)
i. Consciousness gradually
deterioratesdrowsiness
/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

Question 23

mass and 3 nerve palsy

Answer 23

Question 24

eye signs

Answer 24

Question 25

treatment

Answer 25

Urgent evacuation of the haematoma and dealing with the bleeder must be done before late compression occurs

Question 26

subdural haematoma?

Answer 26

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 lacerationhaemorrhage in subdural space

Question 27

subdural hematoma?

Answer 27

● 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

Question 28

extra vs sub dural hematoma

Answer 28

Question 29

chronic subdural hematoma?

Answer 29

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

Question 30

treatment for chronic subdural hematom

Answer 30

burr holes craniotomy Craniotomy – a section of your skull is temporarily removed to allow the surgeon access and remove the haematoma

Question 31

intracerebral hematoma

Answer 31

● Coup / contracoup injuries ● Most common: frontal / temporal lobes ● CT changes usually progressive ● Most conscious patients: no operation

Question 32

diffuse head injury

Answer 32

goes throughout the whole of brain

Question 33

mild brain injury

Answer 33

● GCS score = 13 – 15 ● History ● Exclude systemic injuries ● Neurologic exam ● X-rays as indicated ● Alcohol / drug screens as indicated ● Liberal use of head CT

Question 34

moderate brain injury

Answer 34

● 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

Question 35

severe brain injury?

Answer 35

● GCS score = 3 – 8 ● Evaluate and resuscitate ● Intubate for airway protection ● Focused neurologic exam ● Frequent reevaluation ● Identify associated injuries

Question 36

when to give ct

Answer 36

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

Question 37

how to manage

Answer 37

● 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

Question 38

surgical managment

Answer 38

● Scalp Wounds ● Possible site of major blood loss ● Direct pressure to control bleeding ● Occasional temporary closure scalp injuries 1. Skin 2. Connective tissue (b.v. and nerves) 3. Aponeurosis (galea aponeurotica) 4. Loose areolar tissue 5. Pericranium (skull periosteum firmly attached at the sutures)

Question 39

scalp hematomas

Answer 39

1. Subcutanous 2. Subgaleal 3. Subperiosteal (Cephalhematoma)

Question 40

manage scalp hematomas

Answer 40

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)

Question 41

how to diagnose brain death

Answer 41