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
mortality rate of subarachnoid haemorrhage?
5% of people die before reaching hopsital or having brain imaging
25% dont survive to hospital discharge
What is a subdural haemorrhage?
A collection of blood deep to the dural layer of the meninges and above the arachnoid layer
What are the 3 types of subdural Haematoma?
Acute: symptoms develop within 48 hours of injury with rapid neurological deterioration
Subacute: symptoms manifest days-weeks post-injury with a gradual progression
Chronic: develop over weeks-months and pts may not recall a specific head injury - common in elderly
Cause of a subdural haematoma?
Trauma - blow to the temporal side of the head, rupturing the bridging cranial veins bridging the dura and the brain
Who are subdural haematomas most common in?
Elderly
Alcoholics
(Both have brain atrophy making the vessels more prone to rupture)
Presentation of a chronic subdural haematoma?
History of head trauma with a lucid interval followed by a gradual decline in consciousness
May also be headache, confusion and lethargy
Presentation of a subdural haematoma?
Altered mental status - mild confusion -> deep coma (fluctuations are common)
Focal neurological deficits dependant on location
Headache - often localised to 1 side and worsening over time
Seizures
Memory loss, personality changes or cognitive impairment
N&V - secondary to raised ICP
Physical examination findings for subdural haematoma?
Papilloedema due to raised ICP
Unilateral dilated pupil on side of haematoma due to compression of CN3
Gait ataxia or weakness in 1 leg
Hemiaparesis or hemiplegia - reflecting mass effect and midline shift
Bradycardia, hypertension and respiratory irregularities (Cushing’s triad)
Investigations for ?subdural haematoma?
FBC, U&Es, LFTs, coagulation studies and group & save
Non-contrast CT head
How will CT head appearance vary dependaning on an acute or chronic subdural bleed?
Acute SDH typically has a hyperdense appearance (bright white).
Chronic SDH typically has a hypodense appearance (black/dark grey).
Non-contrast CT head appearance of a subdural haematoma?
Crescent-shaped collection of blood overlying 1 of the cerebral hemispheres and not limited by suture lines
May cause a midline shift or herniation if large enough to cause a mass effect
Management of a subdural haematoma?
Reversal of anticoagulation
AEDs for 1 week to prevent seizures
Conservative - if small with minimal mass effect and no neurological impairment
Surgical options - trauma craniotomy or if large then a decompressive craniectomy
If chronic then surgical decompression with burr hole craniotomy is done
Complications of subdural haematomas?
Transtentorial herniation
Permanent neurological deficits
Coma
Cerebral oedema and raised ICP
Seizures
Intracranial infection
Recurrent subdural haematoma
Death
What is an extradural haematoma aka?
Epidural Haematoma
What is an extradural Haematoma?
An acute haemorrhage between the dura mater and the inner surface of the skull
What is the Pterion?
The anataomical landmark where the parietal, frontal, sphenoid and temporal bones fuse - particularly vulnerable to fracture as the bone is relatively thin
What lies underneath the pterion?
The middle meningeal artery - making it likely to rupture
Cause of extradural haematomas?
Usually a low impact trauma e.g. blow to the head or a fall
Usually in the temporal region where the pterion is and this causes a rupture of the middle meningeal artery
Pathophysiology of an extradural haematoma?
Blood leaks from the middle meningeal artery into the extradural space which strings the dura mater away from the skull
If it continues to increase in size, the ICP increases and this can cause midline short and tantentorial herniation
Presentation of an extradural haematoma?
History of trauma/fall
Initially loses, briefly regains and then loses consciousness again and further deterioriation - termed “lucid intervals”
N&V
Headache
Examination findings in an extradural Haematoma?
Tenderness of skull
Reduced GCS
Cranial nerve deficits e.g. fixed dilation of ipsilateral pupil
Motor or sensory deficits
Hypereflexia and spasticity
Babinskis sign
Cushings triad - bradycardia, hypertension, irregular breathing
Investigtaions for ?extradural haematoma?
FBC, U&Es, CRP, coagulation and group & save
Non-contrast CT head
CT findings in extradural haematoma?
Biconvex/lentiform hyperdense collection around the surface of the brain that is limited but the suture lines of the skull
Management of extradural haematoma?
Correct anticoagulation
Prophylactic antibiotics may be given especially if open skull fracture
AEDs
Agents to reduce ICP may be given e.g. IV mannitol
If it’s >30cm - manage surgically e.g. burr hole craniotomy or trauma craniotomy or hemicraniotomy
Is <30cm with.. low thickness, minimal midline shift and GCS >8 and no focal neurological deficits = conservative management
Complications of extradural Haematoma?
Transtentorial coning -> coma and death
Infection
Cerebral ischaemia
Seizures
Cognitive impairment
Hemiparesis
Hydrocephalus
Brainstem injury due to raised ICP
Overall mortality rate of extradural haematomas?
30%
Poor prognostic factors for extradural haematomas?
Older age
Temporal location
Low GCS at presentation
Evidence of herniation or raised ICP
What is an intracerebral haemorrhage?
Aka a haemorrhagic stroke
A collection of blood within the substance of the brain e.g. caused by hypertension, brain tumour, aneurysm, infarct
Present similarity to an ischaemic stroke
CT imaging shows a hyperdensity within the substance of the brain
What is terson syndrome?
Intraocular haemorrhage associated with SUH, intracerebral haemorrhage or TBI
Why can an oculomotor nerve palsy occur with a SAH?
Aneurysm of the posterior communicating artery can case it
Increased ICP, midbrain injury or uncal herniation can also cause it
