Glioblastoma

Question 1

What are causes of seizures?

Answer 1

• Stroke
• Electrolyte imbalances; e.g. hyponatraemia, hyperglycaemia, hypocalcaemia, hypomagnesia
• Abscess
• Meningitis
• Drugs
• Underlying epilepsy

Question 2

What areas of the brain are associated with memory and personality? Be specific.

Answer 2

Personality is formed by the limbic system and projections to the prefrontal cortex.

Decision-making and reward is associated with dorsomedial prefrontal cortex.

Short term memory depends on dorsolateral prefrontal cortex. Limbic system (mammillary bodies in particular) are critical as well.

Hippocampus is important in encoding short term to long term memories.

Long term memories are widely stored throughout the cerebral cortex.

Question 3

Describe the Papez circuit.

Answer 3

Papez circuit is the limbic system which is associated with mood, emotions, personality and memory.

It involves cingulate gyrus, mammillary bodies, anterior thalamic nucleus, amygdala, fornix and hippocampus.

Cingulate gyrus –> hippocampus –> fornix –> mammillary bodies –> hypothalamus and ant. thalamus input –> response

Question 4

What pharmacological agents do you give (2) for patients with cerebral oedema?

Answer 4

1. Dexamethasone (corticosteroid)

2. Mannitol (osmotic diuretic)

Question 5

How would you manage a patient who is post-icterus seizure with signs of raised ICP with underlying primary brain tumour?

Answer 5

• Intubation and adequate temporary ventilation
• Prophylactic anticonvulsant (e.g. Keppra)
• Tumour resection
• Brain MRI every 6 months to 1 year
• Radiotherapy or radiosurgery can be used if tumour is inaccessible

Question 6

What are the different types of primary brain tumours and where are they likely to be located at?

Answer 6

Can be classified by cell types:

• Glioblastoma multiforme
• Meningioma
• Schwannoma
• Astrocytoma
• Medulloblastoma
• Ependymoma
• Oligodendroglioma

Tumours in adults tend to arise above tentorium cerebelli, and children below it.

Question 7

What are the characteristics of glioblastoma multiforme?

Answer 7

• Most aggressive form of astrocytoma
• Most common
• Arises in cerebral hemisphere and crosses midline
• It is associated with coagulative necrosis, central area of necrosis and surrounding edge

Question 8

What are the characteristics of oligodendroglioma?

Answer 8

It forms calcified tumour in the white matter.

It usually involves the frontal lobe, which can present with seizures.

Question 9

What are the characteristics of meningiomas?

Answer 9

They are benign, more common in females. They express oestrogen receptors, and does not invade into the cortex.

Question 10

What are the characteristics of ependymomas?

Answer 10

They are common in kids, and it arises in the 4th ventricle. Therefore, it can cause obstructive hydrocephalus.