Question 1

A CT head (non-contrast) was performed:

Which of the following intracranial abnormalities is shown?

Extra-dural and sub-dural haematoma are extra-axial collections.

Question 2

MRI brain was performed:

Which of the following defects is most likely to be found on examination?

The MRI shows a pituitary tumour. Pituitary adenomas can be divided into marcoadenomas and microadenomas. A macroadenoma is greater than 10mm in size and is the more common type. The tumours can be further classified into functioning and non-functioning depending on whether they exhibit endocrine activity. The most common functional tumour is a prolactinoma.

The normal pituitary lies within the pituitary fossa, but when it enlarges compresses on the superiorly situated optic chiasm causing a bilateral temporal hemianopia (bitemporal hemianopia). See more on the visual pathway and defects at: http://www.unmc.edu/Physiology/Mann/pix_7/vis_field.gif

Question 3

Masses at the cerebellopontine angle may present clinically with a cerebellopontine angle syndrome. This is caused by a space occupying lesion at the junction of the cerebellum and the pons, which includes important structures such as the Vth, VIIth and VIIIth cranial nerves,

Signs of CPA syndrome include:

• ipsilateral deafness (sensori-neural)
• nystagmus
• reduced corneal reflex
• Vth and VIIth nerve palsies
• ipsilateral cerebellar signs

The commonest cause (accounting for approximately 80% of masses) is a vestibular schwannoma (acoustic neuroma). These are usually benign tumours of the vestibular portion of the VIIIth cranial nerve. They are associated with neurofibromatosis Type 2.

Neurofibromatosis Type 2 (remember 2!)
Chromosome 22
2 (bilateral) acoustic neuromas

Question 4

This is a classical appearance of multiple sclerosis on MRI. MRI is the premier imaging modality for visualizing the inflammatory demyelinating plaques which are a feature of the disease. Plaques may occur in the cerebral hemispheres, cerebellum, brainstem, and spinal cord, classically in a periventricular distribution (see image).

However, multiple sclerosis is a clinical diagnosis, supported by imaging and CSF analysis findings. It is a sporadic disease process.

Question 5

What other clinical problem would fit with the diagnosis of anti-phospholipid syndrome?

Anti-phospholipid syndrome (APS) is a condition characterized by recurrent venous or arterial thrombosis and/or fetal losses in conjunction with persistently elevated levels of antibodies directed against membrane phospholipids typically anti-cardiolipin antibody. Several autoimmune diseases are associated with APS, the commonest being systemic lupus erythromatosis.