Cases for finals #6 – Examination

  • Speech – normal
  • HMF – normal
  • Cranial nerves – right facial weakness (including forehead); failure of lateral gaze to right
  • ULs – tone normal; power EF 4/5, EE 3/5, distal power 4/5, reflexes brisk on left
  • LLs – tone normal; power HF 3/5, HE 5/5, KF 4/5, KE 5/5, reflexes brisk on left
  • Sensation intact

 

Okay, so this does look like a brainstem lesion, and the abrupt onset suggests “vascular” – ischaemic, haemorrhage, AVM etc.

Forehead-involving weakness should be “peripheral” – like in Bell’s palsy – but if you knobble the facial nerve nucleus in the pons, then you get a “lower” looking palsy.

The sixth nerve nucleus controls abduction, and is very close to the seventh. How do I know? Seven comes after six.

So far, so good.

There is an UMN/pyramidal weakness on the left too, so this must be “central”.

Why would a young man develop a brainstem stroke? Neck pain in this setting is likely to be a vertebral artery dissection. It’s not a rare as you might think, and doesn’t always relate to preceding trauma.

Image result for vertebral artery dissection

Aside from the usual ABC stuff, and bloods, you are going to want to get an ECG and then a scan of the brain and contrast-enhanced angiography.

CT will rule out a bleed, but MRI will tell you far more.

Image result for right pontine stroke mri
right pontine infarct
Image result for right pontine stroke dwi
this fuzzy image is diffusion weighted imaging (aka DWI) – it is bright in acute stroke and is a very useful MRI sequence to look at if you suspect stroke.

Speak to the radiologists beforehand and they will (happily) advise on what scans to do.

Image result for vertebral artery dissection mri
angiography (CT or MR) will show a rather weedy looking vessel
Image result for vertebral artery dissection mri
note the crescent of high signal in the right vertebral artery. This is probably the best way to pick up a vertebral dissection.

The lecture on stroke and TIA gives you a little more on how to approach vascular neurology.

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