5. a. Head Injuries Flashcards
What effects does an uncal herniation have?
CN3: dilated pupil
PCA: stroke
Corticospinal tract in midbrain: contralateral hemiparesis
Eventually results in ipsilateral weakness
What effect does a subfalcine herniation have?
ACA: weakness in leg
What effect does a transforaminal herniation have?
Cushing response
- Raised ICP
- Bradycardia
- erratic breathing
What is the mechanism of the Cushing response?
Herniation puts pressure on the brainstem, causing hypoxia in the central chemoreceptors
BP is increased to increase perfusion, and due to high BP baroreceptors in the CVS cause reflex bradycardia
Pressure on the medulla causes erratic breathing
How is cerebral perfusion calculated?
MAP-ICP
How is MAP calculated?
Diastolic + 1/3pulse pressure
What are the systemic causes of secondary brain injury?
Hypoxia, hypercapnia
Hypotension
Hyperthermia
Poor glycaemic control
What are the intracranial causes of secondary brain injury?
Brain swelling Brain shift and herniation Raised ICP Post-traumatic fits Infection
What is the treatment for extradural or acute subdural haematoma?
Emergency craniotomy
How is chronic blood differentiated from acute blood in a subdural haematoma?
Acute is whiter
What patient groups are chronic subdural haematomas seen in?
Elderly, anticoagulants, alcoholism
What is the treatment for a chronic subdural haematoma?
Burr hole drainage
What is the treatment for an intracerebral haematoma?
Usually conservative as blood can be resorbed
Evacuate the haematoma if raised ICP or midline shift
When should a diffuse axonal injury be suspected?
Prolonged unconsciousness without a mass lesion
What is the macroscopic appearance of the brain in diffuse axonal injury?
Ventricles compressed
Sulci visible
What is the treatment for a diffuse axonal injury?
Conservative
Decompressive craniectomy
What are the stages for eyes in the Glasgow coma scale?
- does not open
- opens to pain
- opens to command
- opens spontaneously
What are the stages for verbal response on the Glasgow coma scale?
- no speech
- incomprehensible sounds
- inappropriate words
- confused speech
- orientated
What are the stages for motor response on the Glasgow coma scale?
- no movement
- extension to pain
- abnormal flexion to pain
- normal flexion to pain
- localises to pain
- obeys commands
What is the management of raised ICP?
Keep head at 30 degrees Mannitol and furosemide (avoid low vol) Hypertonic saline Sedation, analgesia Induce hyperventilation and hypothermia
What is the surgical management of raised ICP?
ICP bolt to monitor pressure
Surgical removal of pathology
External ventricular drain
Decompressive craniectomy
