www.emtldr.com

Step 1: Take a breather. Look at the eyes!

The elephant in the room is a posterior TIA or stroke, but less than 1% of posterior strokes are missed. Ensure a standard stroke screener (NIHSS) has been completed. The missed ones almost always are NIHSS <4 in which case urgent thrombolysis / clot retrieval would have likely not made a difference, though sometimes having earlier secondary prevention can have a significant benefit for patients. Eye findings are more useful than MRI, which are in turn more useful than CT Brain + neck angiogram.

Step 2: Be Diagnostically Hungry

…assuming NIHSS 0, and all diagnositc criteria for the following differentials are met.

Triggered Positional Vertigo / BPPV:
– triggered by head movement, relieved lying still.
– Positive dix/hallpike with (1) delayed onset, (2) fatiguing, (3) typical vertical upbeating/rotating inducible nystagmus.

Intermittent Episodic Vertigo: Vestibular migraine
– formally diagnosed migraine (MRI negative, meeting IHS criteria)
– has had previous episodes of similar aura>>HA>>vertigo.

Acute Vestibular Syndrome (continuous nystagmus): Vestibular Neuritis
– Clear the HINTS exam
— Catch up saccades observed on head impulse to the ____.
— Nystagmus fast beating to one horizontal direction only. Otherwise no pathological nystagmus (no rotational, vertical, or bidirectional vertigo)
— Negative test of skew.
– Able to walk: people with vestibular neuritis can usually walk – with some difficulty but they can walk. People with posterior strokes cannot comprehend their body’s position in time/space and will even have difficulty transferring from a chair to bed.
– Gross hearing test normal: any hearing deficit suggests a stroke.

Step 3: Posterior Stroke Workup

If unable to diagnose BPPV / Vestibular migraine / Vestibular Neuritis with all clinical criteria required.

1) Perform a focused examination for posterior stroke signs.

2) Imaging
Acutely in ED, this would be a CT Brain + Neck/COW angiogram to identify major occlusions to the vertebrobasilar system / posterior circulation. Ultimately a MRI is required to look at the posterior circulation territories

3) Disposition Planning
Stroke admission for ongoing symptoms, vs discharge on a TIA pathway for secondary prevention.

Many pearls from this article were from the Vertigo Talk at ASM2024 by Stuart Swadron, FACEP