What is implied by dorsal pontine haemorrhages?
Severe diffuse axonal injury
Why do you get a PCA infarct with raised ICP?
Due to the PCA being compressed against the tentorium
What are the histological features of DAI?
Gliding / shearing forces cause disruption of axoplasmic transport resulting in retraction balls **
What is the grading of DAI?
What is chronic traumatic enchephalopathy?
Repeat head injuries resulting in a neurodegenerative tau pathology (tauopahty) affecting the deep sulci
What is the incidence of TBI?
250 per 100,000 population based on TBI hospital admissions
Alteration in brain function or evidence of brain pathology caused by an external force
What is the weight of the brain?
What is elastance?
Elastance = dPressure / dVolume
What is compliance?
Compliance = dVolume / dPressure
What are the indications for ICP monitoring?
What is the conversion between cmH20 and mmHg?
10cmH20 = 7mmHg
What are Lundberg waves?
A waves = plateau waves B waves =
What is Pouseille's equation?
Where does autoregulation occur? CO2 reactivity?
Pial arteries Pial small vessels
What are Duret haemorrhages?
What is the Marshall classification?
** Diffuse 1 = normal CT Diffuse 2 = visible basal cisterns Diffuse 3 = compression of the basal cisterns Diffuse 4 = signs of raised ICP + shift Mass lesion = mass lesion / ICH >25 cc fill in the rest!
Decision tree of Marshall classification?
Abn yes / no Mass yes / no (mass requiring evacution yes / no) cisterns yes / no midline shift yes / no
How do you classify the mechanisms of TBI?
Closed, penetrating, crush and blast. There is overlap
What are the tiers of treatment for raised ICP?
Tier 1 - HOB, sedation / analgesia, intermittent ventricular drainage, repeat CT Tier 2 - Hyperosmolar therapy, PCo2, paralysis Tier 3 - DHC, barbiturates (hypotherapy in rescueICP has worse outcome)
When should orthopaedic patients be performed in TBI?
Delay for 48 hours until ICP is stable
When should clexane be given in TBI?
Within 72 hours (prophylactic IVC filter can be placed if big contusions etc) Note - 20% of TBI will have a VTE
How should you treat an elderly patient on anticoagulation with ASDH?
Consider it to be similar to EDH as the elderly patient will have minimal brain injury if surgery is performed earlier
Which penetrating injuries carry a very low prognosis?
Transventricular and multilobar path / injury
What is the evidence for abx in penetrating head injury?
How do you remove a penetrating foreign body?
How extensive do you debride a penetrating head injury?
What are the principles of management for penetrating head injury?
Antibiotics Full exposure Control of vascular components Minimal debridement Water tight dural closure (depending on ICP)
What are the complications of penetrating head injury?
Infection Sinus - mucocoele Pseudo-aneurysm ..
How do you manage a pseudo-aneurysm?
What is the relationship between ICP and volume?
How is CBF affected by CO2?
Rising CO2 affects ICP with a sigmoidal relationship
What are the reversible factors of raised ICP?
Sedation / paralysed
Which study showed no difference with using ICP monitoring?
BEST:TRIP (Chestnut et al 2012)
What are the outcomes of DECRA?
Decompressive craniectomy worsens outcome even though ICP was lower
Early decompression at ICP 20mmHg
More people had blown pupils in the surgery group
What are the outcomes of RescueICP?
Overall survival is increased with decompressive hemicraniectomy but they are made vegetative
High proporion of bifrontal craniectomies
Cranioplasty side-effects were not counted
What BP do you aim for in TBI?
What does cerebral microdialysis measure?
Mitochondrial dysfunction: Lactate to pyruvate ration
What is brain tissue oxygenation monitoring?
How does it work?
Explain the rational of jugular venous saturation
What does Xe-CT show?
How does near infrared spectroscopy work?
Different wavelengths correspond to HbO2 etc so able to monitor the response to treatment
Does gender affect TBI outcome?
When would you place a brain tissue monitor?
...Variable, most would place with any depressed GCS
What threshold would you treat at brain tissue oxygenation?
Brain trauma foundation recommend >15 but more recent evidence suggests 20.