Head Anatomy, Assessment, Injuries: Uncal Herniation, High ICP, 1ary/2ndary Head Injury, Basal Skull Fracture, ED, SD, SA, IC Hemorrhage, Contusion, Diffuse Axonal Injury, Concussion Flashcards
How to calculate cerebral perfusion pressure
-what makes up ICP
CPP = MAP (50-150mmHg) - ICP
ICP
- CSF volume
- blood volume
- brain volume
Epidemiology of head injury
Risk factors
Almost half in children
Risk factors
-alcohol
-extremes of age
Clinical signs of head injury
Head
- bruising
- laceration
- palpable fracture
Basal fracture
- racoon eyes
- Battle signs
- CSF, blood from ear or nose
- CN7, 8 palsy
Neuro signs
How to assess severity of head injury
- GCS after initial resus
- what does each score mean?
GCS
Severe U8
Moderate 9-12
Mild 13-15
Eyes 4 -spontaneous 3-V 2-P 1-U
Speech 5-spontaneous 4-confused 3-words 2-sounds 1-none
Motor 6-spontaneous 5-localising 4-withdrawal from pain 3-flexed on pain 2-extended on pain 1-none
Assessment of head injury
-what would you do?
LOC - GCS
Focal neuro deficit
- pupil size and response - unequal/unresponsive pupils due to ext compression of nerve
- limb mv (long tract involvement)
- posture, reflexes
Signs of ICP
- Cushings triad - bradycardia, irregular RR, wide BP
- headache, vomiting, confusion
Head injury + low BP => look for bleed elsewhere
-bleed in brain always causes ICP
When to admit to hospital
Reduced consciousness Skull fracture Persistent neurological symptoms/signs Difficulty assessing patient - alcohol Significant medical conditions - coagulopathy No carer around
Initial management of head injuries
AIM to optimise O2 supply and perfusion to prevent 2ndary brain injury
Airway - maintain, protect, O2 Breathing - support gas exchange Circulation - maintain arterial pressure Disability - assess, monitor for deterioration Manage pain effectively
When would you do a CT head
- 1hr of risk being identified
- 8hr of injury
GCS U13 initially/not 15 in 2hrs Suspected open/depressed/basal skull fracture Seizure Vomited twice Neurodeficit
LOC/amnesia since injury
- 65+
- Hx of bleeding/clotting
- Dangerous MOI
- Retrograde amnesia
When to refer to neurosurgery
Skull fracture with
- confusion
- depressed level of cosciousness
- focal neuro signs
- fits
Persisting coma, confusion Worsening GCS, focal neurology Seizure without full recovery Penetrating injury Depressed skull/BOS fracture CSF leak
When to discharge from ED
No LOC Minimal post traumatic amnesia No active vomiting No severe headache No seizures Able to walk unaided, ADLs Will leave accompanied by and stay with competent adult No significant other risk factors - not on warfarin, no chronic ETOH
TBI - extradural hematoma
- pathophysiology
- presentation
- causes
- CT head findings
Bleed between dura and skull - often MMA
- blow to side of head
- acceleration, deceleration trauma
High ICP
Lucid interval
Lemon
Conservative
If ICP high => surgical decompression
TBI - subarachnoid hematoma
- pathophysiology
- causes
- presentation
- CT head findings
Spontaneous rupture of vessels in context of head trauma/ruptured aneurysm
Thunderclap occipital headache
Hyperdense blood in SA space
-if no signs but suspect SAH => LP 12hrs from onset to assess for RBC in CSF
Neurosurgery referral
- Nimodipine
- Phenytoin
- Antiemetics, analgesia
- Surgical coiling/clipping if caused by aneurysm
- Ventricular draining if hydrocephalus
TBI - subdural hematoma
- pathophysiology
- causes
- presentation
- CT head findings
Bleed between dura and arachnoid, often around frontal, parietal
Low impact trauma in older adults, alcoholism, AC users
Raised ICP
Lucid interval but symptoms arise slower than extradural
Banana
Reduce ICP - surgical decompression
TBI - intracerebral hematoma/haemorrhagic stroke
- pathophysiology
- presentation
- causes
- CT head findings
- management
Collection of blood within brain from
- HTN
- aneurysm, AVM, infarct
- truma
- brain tumour
Similar presentation to ischemic stroke
May have decrease in consciousness
Hyperdensity within brain
Conservative
-evacuative surgery needed if large clots + impaired consciousness
Secondary brain injury
- what is it
- effects of it
Original injury exacerbated by
- cerebral edema
- ischemia
- infection
- herniation
Cerebral autoregulation disrupted => more susceptible to ICP changes, hypoxia
Signs of ICP
Headache
Vomiting
Reduced consciousness
Papilloedema
Cushing triad
- widening pulse pressure
- low HR
- irregular breathing
Investigations and monitoring
FBC, U&E, LFT, glucose, clotting, cultures - impact on other organs and find cause Toxicology screen CXR - infection? CT head LP if safe
Management of ICP
AIM TO LOWER ICP, AVERT SECONDARY INJURY
Focal cause => neurosurgery
-burr holes, craniotomy
ICP monitoring in GCS3-8 with/without abnormal CT
Holding measures until definitive
- 45 degree head elevation
- IV mannitol/furosemide
- controlled hyperventilation
Basal skull fractures
- pathophysiology
- causes
- presentation
- management
Fracture of cranial floor
Often from falls, RTAs, assault
Racoon eyes CSF from nose and ears Blood in middle ear Battle sign - bruise on mastoid VII, VIII dysfunction => facial paralysis, hearing loss
TBI management
CSF leak management - conservative
-frequent cultures taken for meningitis monitoring
Diffuse axonal injury
- pathophysiology
- causes
- presentation
- management
Mechanical shearing following deceleration => tearing of axons
RTAs, child abuse
Diagnosis only suspected when patients do not make a neurological recovery
CT head generally normal
Preventing secondary effects
-poor prognosis
Contusion vs concussion
- pathophysiology
- causes
- presentation
- management
Concussion - forceful injury to the brain Contusion - bruised brain -headache -LOC -amnesia -ICP symptoms, seizures -confusion, irritability
Concussion - clinical diagnosis
Contusion
-head CT, MRI - assess for hemorrhagic lesions
Both generally resolve with time
-if symptoms do not resolve, complications => neuro management
Uncal herniation
-pathophysiology, presentation
Monroe Kelly doctrine -small ICP => CSF loss -when this is no longer possible => ICP increases rapidly and impairs blood flow -leads to neuronal death CPP = MAP - ICP
ICP => herniation puts pressure on brain vasculature => ischemia
-corticate or cerebrate positioning
Decrease ICP - craniotomy
Basal skull fracture
- presentation
- investigations
- management
Racoon eyes Battle sign Oto, rhinorrhea Hematotympanum Cranial nerve palsy
Head CT within 1hr
ATLS stabilisation and neurosurgery referral
