Brain Tumours

• Brain tumours range from benign (e.g., meningiomas) to highly malignant (e.g., glioblastomas).
• Brain tumours may be asymptomatic, particularly when they are small.
• As brain tumours grow, they present with progressive focal neurological symptoms depending on the location of the lesion.
• Brain tumours often present with symptoms and signs of raised intracranial pressure (intracranial hypertension).
• A growing tumour takes up room within the skull, leaving less space for the other contents (such as the cerebrospinal fluid), causing a rise in the pressure within the intracranial space.
• A common exam scenario is an unusual change in personality and behaviour, which indicates a frontal lobe tumour.
• The frontal lobe is responsible for personality and higher-level decision-making.
• The main options for the management of brain tumours are surgery, chemotherapy, radiotherapy, and palliative care.
• Acoustic neuromas are benign tumours of the Schwann cells that surround the auditory nerve, which innervates the inner ear.
• Acoustic neuromas occur at the cerebellopontine angle and are sometimes called cerebellopontine angle tumours.
• Acoustic neuromas are also called vestibular schwannomas.
• Pituitary tumours can cause hormone deficiencies or release excessive hormones, leading to conditions such as Acromegaly, Hyperprolactinaemia, Cushing’s disease, Thyrotoxicosis, and Acoustic Neuroma.
• Biopsy gives the definitive histological diagnosis, usually obtained during surgery to remove the tumour.
• Schwann cells provide the myelin sheath around neurons of the peripheral nervous system.
• The management of brain tumours depends on the type and grade, guided by the multidisciplinary team.
• The typical patient with an acoustic neuroma is a 40-60 year old presenting with a gradual onset of unilateral sensorineural hearing loss, unilateral tinnitus, dizziness, or imbalance, a sensation of fullness in the ear, and facial nerve palsy if the tumour grows large enough to compress the facial nerve.
• Acoustic neuromas are usually unilateral.
• Bilateral acoustic neuromas are associated with neurofibromatosis type 2.
• Management options for acoustic neuromas include conservative management with monitoring, surgery to remove the tumour, radiotherapy to reduce the growth, and MRI scan is the first-line investigation in patients with a possible brain tumour.
• The cancers that most often spread to the brain are Lung, Breast, Renal cell carcinoma, Melanoma, and Pituitary Tumours.
• Gliomas are graded from 1 to 4.
• Papill-oedema refers to the swelling of the optic disc.
• Meningiomas are usually benign, but they take up space, and this “mass effect” can lead to raised intracranial pressure and neurological symptoms.
• In patients presenting with headaches, the concerning features that may indicate intracranial hypertension include constant headache, nocturnal (occurring at night) headache, worse on waking, worse on coughing, straining or bending forward, vomiting, and papilloedema on fundoscopy.
• Papilloedema can be seen on fundoscopy as blurring of the optic disc margin, elevated optic disc, loss of venous pulsation, engorged retinal veins, haemorrhages around the optic disc, Paton’s lines, and more.
• The main three types of gliomas, from most to least malignant, are Astrocytoma, Oligodendroglioma, and Ependymoma.
• Pituitary tumours tend to be benign.
• Gliomas are tumours of the glial cells in the brain or spinal cord.
• Glial cells include astrocytes, oligodendrocytes and ependymal cells.
• Intracranial Hypertension can be caused by brain tumours, intracranial haemorrhage, idiopathic intracranial hypertension, abscesses or infection.
• Glial cells surround and support the neurones.
• The sheath around the optic nerve is connected with the subarachnoid space.
• Grade 1 is the most benign (possibly curable with surgery), and grade 4 is the most malignant (e.g., glioblastoma multiforme).
• Papilloedema is a crucial fundoscopy finding in patients with increased intracranial pressure.
• Other presenting features of raised intracranial pressure may include altered mental state, visual field defects, seizures (particularly partial seizures), unilateral ptosis (drooping upper eyelid), third and sixth nerve palsies, and papilloedema.
• Meningiomas are tumours growing from the cells of the meninges.
• The raised cerebrospinal fluid (CSF) pressure flows into the optic nerve sheath, increasing the pressure around the optic nerve behind the optic disc causing the optic disc to bulge forward.