Space Occupying Lesions and Tumour Lecture Flashcards
Causes of Raised ICP (5)
Focal lesion in brain (SOL) Diffuse lesion in brain (eg oedema) Increased CSF (hydrocephalus) Increased venous volume Physiological (hypoxia, hypercapnia, pain)
Definition of hydrocephalus
Accumulation of excessive CSF within the ventricular system of the brain
Where is CSF produced and where is it absorbed?
Produced by choroid plexus in the lateral and fourth ventricles
Absorbed by arachnoid granulations
What is CSF composed of?
Lymphocytes, Protein, Glucose
Causes of hydrocephalus (3)
Obstruction to flow of CSF eg inflammation, tumours
Decreased resorption of CSF
Overproduction of CSF - rare - tumour of the choroid plexus
Definition - Non-communicating hydrocephalus
Obstruction to flow of CSF occurs within ventricular system
Definition - Communicating hydrocephalus
Obstruction to flow of CSF outside of the ventricular system eg in the subarachnoid space or at the arachnoid granulations
Outcome is hydrocephalus develops
- before closure of cranial sutures?
- after closure of cranial sutures?
- Enlargement of head
2. Expansion of ventricles and increase in intracranial pressure
Effects of raised ICP (4)
Intracranial shifts and herniations
Distortion and pressure on cranial nerves and vital neurological centres
Reduced level of consciousness
Impaired blood flow
Types of shifts and herniations (4)
- Falcine
- Uncal
- Cerebellar
- Transcalvarium
Clinical signs of raised ICP (4)
Papilloedema
Nausea and vomiting
Headache
Neck stiffness
SOL - 4 examples
Tumours - primary brain tumours, mets
Abscess - single/multiple
Haematoma
Localised brain swelling - eg swelling and oedema around infarct
Astrocytoma grading system
1 - pilocytic astrocytoma - 95% survival at 10yrs
2 – diffuse astrocytoma - median survival 7yrs
3 - anaplastic astrocytoma - median survival 2-3yrs
4 - glioblastoma - median survival 10months
Glioblastoma - which has a better prognosis - primary or secondary?
Primary glioblastoma - sx for under 3months, survival 4.7months, common age 62
Secondary glioblastoma - survival 7.8 months, common age 45
Presentation of brain tumour
Symptoms (5)
Signs (2)
Symptoms - focal symptoms, headache, vomiting, seizures, visual disturbances
Signs - focal deficit, papilloedema
Causes of single abscess (7)
Usually focal cause... Otitis media Sinusitis Nasal Facial and dental infections Skull fracture Penetrating injury Neurosurgical procedures
Causes of multiple abscesses (4)
Usually result from septicaemia.. Acute bacterial endocarditis Bronchiectasis and lung abscess Cyanotic heart disease IV drug abuse
Types of cerebral oedema (5)
Vasogenic Cytotoxic Hydrostatic Interstitial Hypo-osmotic
Picture usually mixed
Extradural haemorrhages - usual cause
Usually due to rupture of meningeal arteries and assoc. with skull fractures
Results of extradural haemorrhage
Compress subjacent dura and flatten gyral crests to underlying brain
- uncal gyral/ cerebellar tonsillar herniation
- brainstem compression
- death
What is a subdural haemorrhage and what causes it?
Collections of blood between the internal surface of dura mater and arachnoid mater.
Can vary in size.
Caused by disruption of bridging veins that extend from the surface of the brain into subdural space
Most common site of subdural haemorrhage?
Cerebral hemisphers
What is an acute or chronic subdural haemorrhage?
Acute - clotted blood
Chronic - liquefied blood clot
Acute subdural heamorrhages
Clear history of trauma
Unilateral or bilateral
Assoc. with other traumatic lesions
Gyral contours preserved - pressure evenly distributed
Swelling of cerebrum on side of haematoma
Mass effect
Chronic Subdural Haemorrhages
Less frequently assoc. with a well defined traumatic insult
Often assoc. with brain atrophy
Composed of liquefied blood/yellow tinged fluid separated from inner surface of dura mater and underlying brain by neomembrane
Clinical symptoms of chronic subdural haemorrhages (2)
Altered mental status
Focal neurological deficits
Types of subarachnoid haemorrhage
Spontaneous or traumatic
Most common cause of a spontaneous subarachnoid haemorrage
Rupture of a saccular aneurysm
Another name for a saccular aneurysm
Berry aneurysm
Where do saccular aneurysms occur (2) and which location is more common
90% arise as arterial bifurcation in territory of internal carotid artery
10% in vertebro-basilar circulation
Morphology of subarachnoid haemorrhage
Rupture of berry aneurysms may result in bleeding into the subarachnoid space
May also get intracerebral haematomas adjacent to aneurysms
Infarcts of brain parenchyma may also develop - due to arterial spasm - seen in 40% cases - mass effect of haematoma and raised ICP
Clinical features of subarachnoid haemorrhage (6)
Onset ABRUPT Assoc with... - severe headache - vomiting - loss of consciousness Usually no history of precipitating factor 50% die within several days of onset
