Friday, September 14, 2012

Vertigo



Today we talked about a patient with vertigo who ended up having something really rare.

It gave us a chance to revisit the often tricky approach to vertigo.

Here are some important points:

1) Key question is distinguishing a peripheral from a central cause of vertigo, as the central causes are the most dangerous. There are some clues on history and physical exam that can help:
History: 
- Stroke risk factors: central
- Presence of other neuro symptoms: central
- Presence of other ear-related symptoms: peripheral

Physical:
- Vertical or gaze-evoked (ie changes direction depending on where patient looks) nystagmus: central
- Nystagmus suppresses with visual fixation: peripheral. Note: would also increase when fixation removed, can test this by using fundoscopy, nystagmus seen with ophthalmoscope to increase when you cover the other eye
- Severe unsteadiness (even with eyes open): central (note in peripheral may tilt to side of lesion, romberg positive)
- Any other neuro findings: central

2) Consider brain imaging even if history and physical suggest a peripheral cause in the following cases:
- older patient
- stroke risk factors
- and acute onset vertigo that persists for more than 48 hours

MRI/MRA are needed in this case since CT is not great for our areas of interest: the brainstem and cerebellum.

 Note that a labyrinthine TIA/stroke will look like a peripheral lesion on history and physical.

3) The image above probably depicts something similar to the Dix-Hallpike maneuver, used to diagnose Benign Paroxysmal Positional Vertigo.

Follow this link to see a video of the nystagmus seen in such patients.

Follow this link for a great NEJM review of acute vertigo. It's an oldie but a goodie.

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