Brain metastases Flashcards
Brain tumours are abnormal growths within the brain. There are many different types of brain tumour. They vary from benign tumours _______ to highly malignant ________
benign: meningiomas
highly malignant: glioblastoma
Presentation of a brain tumour?
Often do not have any symptoms, particularly when they are small
As they develop they present with focal neurological symptoms depending on the location of the lesion
Brain tumours often present with symptoms and signs of raised intracranial pressure. As a tumour grows within the skull it takes up space. This leaves less space for the other contents of the skull (such as the CSF) to squeeze in to and leads to a rise in the pressure within the intracranial space.
TOM TIP: A common exam question asks the location of the lesion based on the neurology. A popular exam question describes a patient that has had an unusual change in personality and behaviour. This indicates a tumour in the frontal lobe. Remember that the frontal lobe is responsible for personality and higher-level decision making.
Tom tip
Causes of raised ICP
Brain tumours
Intracranial haemorrhage
Idiopathic intracranial hypertension
Abscesses or infection
Investigation for raised ICP
Papilloedema is a key finding on fundoscopy
Concerning features of a headache that should prompt further examination and investigation include:
Constant
Nocturnal
Worse on waking
Worse on coughing, straining or bending forward
Vomiting
Other presenting features of raised intracranial pressure may be:
Altered mental state
Visual field defects
Seizures (particularly focal)
Unilateral ptosis
Third and sixth nerve palsies
Papilloedema (on fundoscopy)
Pathophysiology of papilloedema?
Papilloedema is a swelling of the optic disc secondary to raised intracranial pressure. Papill- refers to a small rounded raised area (the optic disc) and -oedema refers to the swelling. The sheath around the optic nerve is connected with the subarachnoid space. Therefore it is possible for CSF under high pressure to flow into the optic nerve sheath. This increases the pressure around the optic nerve where it connects with the back of the eye at the optic disc, causing optic disc swelling. This can be seen on fundoscopy examination.
Fundoscopic changes of papilloedema?
Blurring of the optic disc margin
Elevated optic disc (look for the way the retinal vessels flow across the disc to see the elevation)
Loss of venous pulsation
Engorged retinal veins
Haemorrhages around optic disc
Paton’s lines which are creases in the retina around the optic disc
Types of brain tumours include:
Secondary metastases
Gliomas
Meningiomas
Pituitary tumours
Acoustic Neuroma (AKA vestibular schwannoma)
Secondary metastases causes: common cancers that metastasise to the brain are:
Lung
Breast
Renal cell carcinoma
Melanoma
What are gliomas?
Gliomas are tumours of the glial cells in the brain or spinal cord. There are three types to remember (listed from most to least malignant):
Astrocytoma (glioblastoma multiforme is the most common)
Oligodendroglioma
Ependymoma
How are gliomas graded?
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.
What are pituitary tumours, symptoms?
Pituitary tumours tend to be benign. If they grow large enough they can press on the optic chiasm causing a specific visual field defect called a bitemporal hemianopia. This causes loss of the outer half of the visual fields in both eyes. They have the potential to cause hormone deficiencies (hypopituitarism) or to release excessive hormones leading to:
Acromegaly
Hyperprolactinaemia
Cushing’s disease
Thyrotoxicosis
