Neurotrauma Flashcards
What is a Traumatic brain injury (TBI)?
= a form of acquired brain injury, occurs when a sudden trauma causes damage to the brain.
- Can be caused when the head suddenly and violently hits an object or when an object pierces the skull and enters the brain tissue
Anatomy of the brain?
- grey & white matter
- 3 parts = Brainstem, cerebellum, cerebrum
- 4 lobes = Frontal, parietal, temporal, occipital
- R & L Hemispheres
- 12 Crainal nerves
TBI severity (Categories)
Mild = GCS 13-15
Moderate = GCS 9-12
Severe = GCS <8
Three main parts of the brain?
- Brain stem = changes in HR, breathing, BP, Vomiting, swallowing & Digestion
- Cerebrum = intelligence, learning, judgement, speech & memory, hearing, vision, taste & smell, skeletal muscle movements
- Cerebellum = balance, coordination & posture
Pathophysiology of the Brain?
— skull is rigid compartment which holds everything
— Any changes to blood, CSF, Brain, volumes creates pressure build up
— Pressure on the Brain leads to death
What is cerebral blood flow?
— brain has the ability to control its blood supply to match its metabolic requirements
- vasoconstriction and dilation
- CBF increases with
— increase metabolic rate
— Hyperthermia
— seizures
— pain + anxiety
What is cerebrospinal fluid (CBF)?
- purpose = buffer —> thick and buffers the brain through movement (protection
- absorbs
- if blocked = increase of pressure = problem
Types - haemorrhage of the brain
Focal injuries
1. Haematoma
a) Epidural haematoma
b) Subdural Haematoma
c) Subarachnoid haemorrhage
2. Cerebral Contusions
3. Meningitis
Diffused injuries:
1. concussion / mild TBI
2. Diffuse atonal injury DAI
Describe the types of haematomas TBIs?
- Haematoma: haemorrhage of the brain
a) Epidural haematoma (ARTERY) —> middle meningeal artery rupture
— usually due to blow to side of head at pteranodon (thinnest part of skull)
— Rapidly expanding
b) Subdural haematoma (Veins) —> tears in bridging veins that cross the subdural space
— slower symptom onset due to slower nature of bleeding from vein
c) Subarachnoid haemorrhage —> bleeding into the subarachnoid space = raised ICP
What is cerebral contusions?
- Cerebral Contusions —> bruise on surface of the brain
— caused by movement in cranial vault & evolves over time (12-14 hrs to appear on CT)
What is menegitis?
- Meningitis —> inflammation of the meninges of the brain/ spinal cord or both.
Describe concussion/ mild TBI?
- Concussion/ mild TBI
— direct blow
— Diffuse injury
— transient amnesia / LOC
Describe Diffuse atonal injury DAI
- Diffuse atonal injury (DAI)
— Mild-Severe TBI
— Diffuse = microscopic damage
— damages integrity of axon
— ICU ventilated for long period
— MRI diagnosis
Mechanism of injury TBI
— Blunt (common in ED)
— penetrating (bullets, knives)
— MVC
— Falls
— Assults
— Less common:
smoke inhalation, burns, explosion)
What is primary injury TBI?
= injury at time of event
— Primary irreversible injury
— only treatment is prevention of secondary injury —> once damage is done you may not be able to fix
What is secondary injury?
Secondary injury = Follows the initial even (PREVENTABLE)
— e.g. hypoxia, hypercapnia, hypotension (CCP > 60mmHg), metabolic changes
Is concussion a diffuse or focal bleed?
= diffuse
Can diffuse axonal injury be seen on a CT scan?
= no
Is epidural haematoma an arterial or venous bleed?
= Arterial
Is subdural haematoma an arterial or Venous bleed?
= Venous
Can cerebral contusion be seen on a CT scan?
= yes appears over time
After a positive CT scan do all patients need an operation?
= No small bleeds may need to be watched
What are the causes of a secondary brain injury?
— hypoxia
— hypercapnia
— hypotension
— temperature (hypothermia/ hyperthermia)
What is the normal range for ICP?
= >20mmHg
