NOTE — THE COMMENTS BELOW ONLY REFER TO A PATIENT WHO HAS ACTIVE VERTIGO & NYSTAGMUS AT THE MOMENT, there in the office (which is pretty uncommon).
One study found 100% sensitivity & 96% specificity for Stroke if any of the following 3 bedside tests were positive (performed on a patient with active vertigo & nystagmus:
- Horizontal Head Thrust (the most important)
- Direction-Changing Nystagmus with eccentric gaze
- Have them focus continuously on a spot straight ahead
- Turn their head abruptly to one side
- If Labyrinthine disease, response is abnormal: eyes move involuntarily with the head, then dart back to regain focus (bottom pix)
- If Stroke, eyes maintain normal focus (top pix)
- Patients with a peripheral etiology for their vertigo have an abnormal response.
- Normal persons without illness have a “normal response”
- Stroke patients also have a “normal response” [some with cerebellar stroke might have an abnormal response].
2) Direction-Changing Nystagmus with eccentric gaze.
- Nystagmus present when staring straight ahead
- Ask patient to look to right & then left
- If nystagmus starts beating the other way, think Stroke
- Patient focuses continuously straight ahead.
- Cover one eye.
- Uncover it, and cover the other
- Keep repeating
- If you see one eye staring off with skewed alignment for a moment when uncovered, think Stroke
Remember — All the above tests imply that the patient comes in with active vertigo and nystagmus, which is not too common.
Here’s the whole article, for anyone interested [though it’s all a little obscure]: