INTRACRANIAL BLEEDS Flashcards
Layers of the meninges?
Dura mater - directly under the bones of the skull
Arachnoid mater - directly under dura mater
Pia mater - under the subarachnoid space and tightly adhered to the surface of the brain
What are the 2 layers of the dura mater and what lies between them?
Periosteal layer and meningeal layer
Dural venous sinuses are located in between
Function of the dural venous sinuses?
Venous drainage of the cranium and empty into the internal jugular veins
What are dural reflections and what are the 4 types?
These are where the meningeal layer of the dura mater fold inwards upon itself to divide the cranial cavity into several compartments
Falx cerebri, tentorium cerebelli, falx cerebelli, diaphagma sellae
What is contained within the subarachnoid space?
CSF
What are arachnoid granulations?
Small projections of arachnoid mater into the dura which allow for CSF to re-enter the circulation via the dural venous sinuses
What is a subarachnoid haemorrhage?
An intracranial haemorrhage where there is bleeding in the subarachnoid space (where CSF is located) - this is between arachnoid membrane and pia mater
Causes of subarachnoid haemorrhage?
Traumatic - head injury is the most common cause of SAH overall
Non-traumatic (spontaneous):
- rupture of intracranial saccular aneurysm - 85%
- AVMs
- pituitary apoplexy
- arterial dissections
- use of anticoagulants
Conditions associated with berry aneurysms?
Hypertension
Adult PCKD
Ehlers-danlos
Coarctation of the aorta
Presentation of subarachnoid haemorrhage?
Sudden-onset maximum severity occipital headache that peaks in intensity within 5 minutes
N&V
Meningism
Coma
Seizures
Risk factors for subarachnoid haemorrhages?
Age 45-70
Women
Black ethnic origin
Severe head injury
Hypertension
Smoking
Excessive alcohol
FHx
Cocaine use
SC anaemia
CTD
Neurofibromatoiss
ADPKD
Investigtaions for subarachnoid haemorrhage?
Non-contrast CT head - if this is done >6 hours after Sx onset and is normal then do an LP 12 hours following Sx
After SAH is confirmed CT intracranial angiogram +/- digital subtraction angiogram is done to find the causative
What will subarachnoid haemorrhage look like on a non-contrast CT?
Hyper dense (bright) blood distributed in basal cisterns, sulci and sometimes in severe cases the ventricular system
(Note: a negative CT head does not exclude a subarachnoid haemorrhage especially if after 6 hours!!)
Why must an LP be performed at least 12 hours after the onset of symptoms of ?subarachnoid haemorrhage?
To allow the development of xanthochromia which is a RBC breakdown product - this helps to distinguish SAH from a traumatic tap
Findings of CSF from an LP in a pt with ?subarachnoid haemorrhage?
Raised xanthochromia
May be a normal or raised opening pressure
Management of a confirmed aneurysmal subarachnoid haemorrhage?
Bed rest, analgesia, VTE prophylaxis, discontinue and reverse antithrombotics
Oral nimodipine
Interventional neuroradiology e.g. coil or clipping
What is endovascular coiling?
When you insert a catheter into the arterial system and place platinum coils in the aneurysm, sealing it off from the artery
Why do we give nimodipine following a confirmed subarachnoid haemorrhage?
To prevent vasospasm which is a common complication which can result in brain ischaemia
Complications of aneurysmal subarachnoid haemorrhage?
Re-bleeding - most common in first 12 hours - occurs in 10% and has a very high mortality
Hydrocephalus
Vasospasm (aka delayed cerebral ischaemia)
Hyponatraemia - usually due to SIADH
Seizures
poor prognostic factors for subarachnoid haemorrhage
Increased age
Low conscious level on admission
Large amount of blood visible on CT head