Radiological Investigations in Neurology

Question 1

Where is speech predominantly controlled in the brain?

Answer 1

• For most people, speech is controlled on the left side of the brain (partly in frontal, partly in superficial temporal).
• So, in a patient with speech difficulty you would expect to see weakness on the right hand side.

Question 2

What is the time window for thrombolysis in stroke?

What are the risks of thrombolysing after this window?

Answer 2

• 4.5 hours.
• After this window, the risk:benefit is skewed.
• You can actually cause bleeding by thrombolysing outwith this 4.5 hour window.

Question 3

Why is contrast used in a patient who is having brain imaging as a result of suspected stroke?

Answer 3

It gives more than a static image; it gives an idea of the behaviour of the structure, particularly when inserting contrast into the vessels because stroke is a vascular problem.

Question 4

Why, with an extradural haemorrhage is there a lucid period before the onset of confusion?

Answer 4

• The pterior is bumped (middle meningeal is bleeding) and it bleeds into and outside the cranium. To begin with, the pressure is low so there is a lucid period because the brain is, as yet, not being compressed.
• After bleeding for longer, the pressure builds and starts to compress the brain matter, causing the confusion.