Name the components of the hind brain from caudal to rostral, how are the cranial nuclei organized in each component.

How are the clinical signs organized that is characteristic of a brainstem lesion?

Wallenberg's (lateral medullary) syndrome is probably the most typical following VBI. List five signs or symptoms found in Wallenberg's syndrome.

List five causes (other than VBI) of brainstem signs/symptoms.

If you suspect a vasulogenic brainstem lesion, what would you suggest to the physician would be the best imaging investigation to carry out?

Medulla, Pons, Midbrain, Thalamus, Cerebellum. Apart from the olfactory which is parked under the frontal lobe, the remainder are situated in reverse order from caudal to cranial:

• 12,11,10,9 in the medulla
• 8,7,6 in the pons
• 5,4,3 in the midbrain
• 2 in the thalamus/midbrain junction and in the thalamus

Typically they are ipsilateral cranial nerve signs and contralateral long tract signs.

Nystagmus, vertigo, dizziness, dysphagia, dysarthria, Horner's syndrome, ataxia, facial ana/hypoaesthesia, hemilateral pain and temperature sensation loss, dysphonia, perioral numbness/tingling, diplopia.

Intra and extra-axial tumors, hemorrhage, hematomas, vascular malformations, multiple sclerosis, aneurysms, meningitis, arachnoid cysts.

MRI and MRI angiography if VBI suspected. Angiography is the definitive study but presents dangers to the patient that non-invasive imaging does not. However, it is worth noting that there are documented cases of patients stroking from a vertebrobasilar generated brainstem infarction while being positioned for various imaging investigations.