Subarachnoid haemorrhage and brain tumour Flashcards
Define subarachnoid haemorrhage
Bleeding into the subarachnoid space
Pathophysiology of subarachnoid haemorrhage
It is most commonly caused by trauma.
The most common cause of spontaneous SAH is berry aneurysm.
Other causes include:
Arteriovenous malformation
Vertebral artery dissection
Risk factors for subarachnoid haemorrhage
- Hypertension
- Smoking
- Alcohol excess: there is a significantly increased risk with current alcohol abuse
- Increasing age: most commonly presents in people >50 years old
- Family history
- Polycyctic kidney disease
Where do cerebral berry aneurysms usually occur?
What conditions are berry aneurysms associated with?
The majority of berry aneurysms occur in the circle of Willis
Associated with coarctation of the aorta, connective tissue disorders and adult polycystic kidney disease.
Clinical features of subarachnoid haemorrhage
- Thunderclap headache, severe (worst headache of their life), occipital
- May present with:
- seizures
- vomiting
- depressed level of conciousness
- evidence of meningism (photophoia, neck stifness)
Investigations for subarachnoid haemorrhage
- Urgent non-contrast head CT (hyperattenuating material is seen in the subarachnoid space)
- If initial CT is negative but history is suggestive of SAH then a lumbar puncture may be warrented
- Perform from 12 hours of symptoms onset (not earlier)
- Xanthochromia with normal or raised opening pressure
- Xanthochromia is yellow pigmentation of CSF due to degradation of haemoglobin to bilirubin and is present 12 hours post bleed
- CT angigoraphy required to locate source of the bleed once SAH confirmed
Management of subarachnoid haemorrhage
Immediate referral to neurosurgery (intervention should be performed within 24 hours due to risk of rebleeding)
- Nimodipine: 60mg 4 hourly should be offered to all patients immediately upon diagnosis; this is thought to prevent vasospasm and a 21 day course is usually offered
- Endovascular coiling (majority) by an interventional radiologist or neurosurgical clipping
- If features of raised intracranial pressure: consider intubation with hyperventilation, head elevation (30 degrees) and IV mannitol
Potential complications of subarachnoid haemorrhage
- Rebleeding (most common)
- Vasospasm: treated with (induced) hypertension, hypervolaemia and haemodilution (triple H therapy)
- Hydrocephalus: acutely managed with external ventricular drain or long term atrioventricular shunt
- Seizures: seizure prophylaxis often administered
Prognosis of subarachnoid haemorrhage
At 6 months, 25% of patients are dead and 50% are moderately to severely disabled.
What are the different types of brain tumours?
- Secondary metastases
- Gliomas
- Meningiomas
- Pituitary tumours
- Vestibular Schwannoma
How can brain tumours present?
- Focal neurological lesions depending on the location of the lesion
- Symptoms and signs of raised intracranial pressure
- Change in behaviour and personality in a frontal lobe tumour
The most common cancers that metastasis to the brain are:
- Lung
- Breast
- Renal cell carcinoma
- Melanoma
What are gliomas?
What are the three types to remember? (Listed from most to least malignant)
Gliomas are tumours of the glial cells in the brain or spinal cord.
- Astrocytoma (glioblastoma multiforme is the most common)
- Oligodendroglioma
- Ependymoma
(Gliomas are graded from 1-4. Grade 1 are most benign (possibly curable with surgery). Grade 4 are the most malignant (glioblastomas))
What are meningiomas?
Meningiomas are tumours growing from the cells of the meninges in the brain and spinal cord.
They are usually benign, however they take up space and this mass effect can lead to raised intracranial pressure and neurological symptoms.
If pituitary tumours grow large enough they can press on the optic chiasm causing a visual field defect. What is this defect called?
Bitemporal hemianopia
This causes loss of the outer half of the visual fields in both eyes
