Revision - Space Occupying Lesions & Cerebral Venous Thrombosis Flashcards
Location of majority of brain tumours in adults vs children?
Adults –> supratentorial (i.e. cerebrum)
Children –> infratentorial (i.e. cerebellum)
which cancer most commonly spreads to brain?
lung
What is the most common 1ary brain tumour in adults?
Glioblastoma
Unusual changes in personality and behaviour would indicate a brain tumour in what location?
Frontal lobe
What are glial cells?
They surround and support the neurones:
1) Astrocytes
2) Oligodendrocytes
3) Ependymal cells
What is a glioma?
Tumour of the glial cells in the brain or spinal cord
How gliomas graded?
1-4 depending on severity
4 is most malignant (glioblastoma multiforme)
What are the 3 types of gliomas?
1) astrocytoma
2) oligodendroglioma
3) ependymoma
What type of glioma is a glioblastoma multiforme?
Astrocytoma
Prognosis of a glioblastoma?
Around 1 year
How do glioblastomas appear on imaging?
Solid tumour with central necrosis and rim that enhances with contrast.
Associated with vasogenic oedema due to disruption of blood brain barrier.
Histology of a glioblastoma?
Pleomorphic tumour cells border necrotic cells
What do meningomas arise form?
Dura mater of the meninges
Are meningiomas usually benign or malignant?
Usually benign
However, they take up space –> can lead to raised intracranial pressure and neurological symptoms
Histology of meningiomas?
Spindle cells in concentric whorls and calcified psammoma bodies
What is the most common 1ary brain tumour in children?
Pilocytic astrocytoma
Histology of a pilocytic astrocytoma?
Rosenthal fibres (corkscrew eosinophilic bundle)
What is a medulloblastoma?
An aggressive paediatric tumour that arises within the infratentorial compartment.
How does a medulloblastoma spread?
Through CSF
Where is an ependymoma commonly seen?
In the 4th ventricle
What may an ependymoma cause?
Hydrocephalus
Where are oligodendromas typically found?
Frontal lobes
What is a haemangioblastoma?
A vascular tumour of the cerebellum
What condition are haemangioblastomas associated with?
von Hippel-Lindau syndrome
Hearing loss in a vestibular schwannoma?
Sensorineural
Typical presentation of a vestibular schwannoma?
1) typically 40-60 y/o
2) unilateral sensorineural hearing loss
3) unilateral tinnitus
4) dizziness or imbalance
5) sensation or fullness in ear
6) facial nerve palsy (if the tumour grows large enough to compress the facial nerve)
What is the most common paediatric SUPRAtentorial tumour?
Craniopharyngioma
What is the 1st line investigation in patients with a possible brain tumour?
MRI
What drugs can cause idiopathic intracranial HTN?
1) COCP
2) Steroids
3) Tetracyclines
4) Lithium
5) Retinoids
Management of idiopathic intracranial HTN?
1) weight loss
2) carbonic anhydrase inhibitors e.g. acetazolamide
3) topiramate (has the added benefit of causing weight loss in most patients)
4) repeated lumbar puncture may be used as a temporary measure but is not suitable for longer-term management
5) surgery
Role of carbonic anhydrase inhibitors (eg, acetazolamide) in idiopathic intracranil hypertension?
Can reduce CSF production at choroid plexus
Which cranial nerve is most common affected by traumatic brain injury and/or elevated ICP?
CN VI (abducens)
What is cerebral venous thrombosis caused by?
Partial or total occlusion of the cerebral veins and sinuses by a thrombus.
What are some genetic thrombophilias that can predispose to CVT?
1) APS
2) Antithrombin III deficiency
3) Protein C deficiency
4) Protein S deficiency
5) Factor V Leiden
6) Hyperhomocysteinemia
What is the most common cause of infection causing CVT?
Staph aureus - spread from infection of the sinuses
Give 3 examples of infections causing CVT
1) Staph. aureus from sinusitis
2) Meningitis
3) Subdural empyema
Give 2 procedures that can cause CVT
1) Jugular venous cannulation
2) LP
Give some examples of chronic inflammatory diseases that can cause CVT
1) SLE
2) IBD
3) Sarcoid
4) Granulomatosis with polyangiitis
What medication increases the risk of CVT?
Steroids
What is the 1ary mechanism of injury in CVT?
1) a cerebral vein or sinus becomes partially or totally occluded by a venous thrombus
2) deoxygenated blood will begin to pool within the brain parenchyma
3) this causes an increase in cerebral venous pressure
Resulting complications from CVT?
1) cerebral ischaemia
2) oedema
3) haemorrhage
4) raised ICP
Symptoms of CVT?
1) headache
2) seizures
3) focal neurological deficits:
- hemiparesis
- fluent aphasia
- sensory/visual field defects
4) changes in metnal state:
- encephalopathy
Symptoms will vary depending upon the site and extent of thrombosis.
What is the most common site of CVT?
Sagittal sinus thrombosis (60%)
How does sagittal sinus thrombosis typically present?
Most commonly presents with bilateral motor deficits and seizures
Which sinus is most likely to be affected by septic CVT?
Cavernous sinus - with infection spreading from nearby sinuses, nose and middle ear
CVT can be classified into what two categories depending upon its aetiology?
1) aspectic CVT
2) septic CVT
What is aseptic CVT?
An embolism arising from a non-infective cause, often due to underlying hypercoagulable state but has a variety of causes.
This is the most common type of CVT
Where does aspetic CVT typically occur?
Superior sagittal sinus
What is septic CVT?
An embolism arising from a primary source of infection, most commonly sinusitis, osteomyelitis, otitis media or rarely septicaemia.
Where does septic CVT typically occur?
Cavernous sinus
What is the most frequent symptom experienced by CVT patients?
Headache
1st line investigation in suspected CVT?
MRI + MR venography
Management of CVT involves what 3 key elements?
1) acute antithrombotic therapy
2) acute symptom management
3) long term management
What is used for acute antithrombotic therapy in CVT?
LMWH or UH
What does acute symptom management involve in CVT?
1) Raised ICP:
- bed elevated
- osmotic therapy (mannitol or hypertonic saline)
- brain herniation may need emergency decompressive surgery
2) Seizures: anticonvulsants
3) Infection/inflammation: Abx, steroids
Mx of raised ICP?
1) elevate bed
2) osmotic therapy: IV mannitol or hypertonic saline
Long term management of confirmed CVT?
Long-term mx with warfarin
What is anticoagulant of choice for long-term mx in CVT?
Warfarin
INR target in patients on warfarin in CVT?
2.5
How long is warfarin continued for in CVT?
Provoked CVT –> 3-6 months
Unprovoked CVT –> 6-12 months
Which artery is typically affected in temporal arteritis that causes vision loss?
Occlusion of the posterior ciliary artery (a branch of the ophthalmic artery) –> ischaemia of the optic nerve head.
What will a temporal artery biopsy show in temporal arteritis?
Multinucleated giant cells –> skip lesions may be present
