1ST STEP — Before you go anywhere, determine if it’s Vertigo on the one hand, or non-specific, non-vertiginous dizziness / lightheadedness on the other. They’re two entirely different & unrelated symptoms; their etiologies have nothing to do with each other.
The key to defining Vertigo is that it’s unidirectional. It may be perceived as the person spinning, the environment spinning, the person being thrust upon the environment, or the environment being thrust upon the person. But whichever, everything keeps moving in the same direction.
Dizziness, on the other hand, is anything else. It may be a feeling of wobbling, fuzziness, about to faint, unsteadiness, whatever. All that matters is that it isn’t vertigo!
Some patients can’t explain sufficiently for me to decide, but I have to know! Otherwise it’s impossible to proceed with a differential. Two tricks help:
1. Demonstrate. Spin around on your exam chair [if it doesn’t rotate, just spin around yourself]. Sweep circles in the air with your finger. And ask, “Are you, or is the room spinning in on direction, like this? Or, are things moving every which way?” Then wobble yourself a tiny bit in erratic directions.
People with true vertigo are invariably able to pinpoint the difference. If the patient doesn’t quite understand what you’re aiming at, it’s probably not vertigo.
2. If the patient thinks they actually had vertigo, that things were spinning, I inquire, “Which direction? This way [sweep your finger in circles to the right…], or that way [then to the left]?” Even though the difference might be useful in localizing a lesion, I don’t really care. All I want is to get an idea that things were really moving unidirectionally.
So if the patient stops to think hard, trying to decide, and I get the sense they know exactly what I’m talking about but just can’t remember which way they spun, I’m happy. It’s vertigo. However, if they respond, “Huh? No, not like that,” then I chart, “Dizziness NOS, not vertigo” and go on from there.
Let’s go on from there. Say you’ve decided the chief complaint is…
DIZZINESS — Tough. We’ll hardly discuss this [remember when your English teacher always taught you how not to begin an essay?]. That’s because Dizziness is so non-specific, it could mean almost anything. The most common cause is anxiety, but it could also be something like stroke, sepsis, hypoxia, angina, metabolic derangements, etc. You’ll need to seek a better symptom to work off of for the differential.
Start by seeking the serious ones:
- If the dizziness is exertional, inquire about simultaneous dyspnea, chest pain, nausea, diaphoresis, coronary artery risk factors. Explore cardio-pulmonary causes if this inventory is suggestive.
- If the patient is febrile, search for serious infections.
- If the dizziness is orthostatic (occurs upon arising), review new meds, be sure there’s no reason for impending shock, consider Addisons [???], encourage fluid intake
- If there have been falls, do a good neuro exam, particularly cerebellar function.
- Be concerned if the symptom acute and continuous, with no prior history thereof. Be much less worried if the symptom is more long-standing, or comes & goes throughout the day, or has recurred in the past.
- Watch out if an elderly patient complains of new, acute dizziness (or new, acute anything, for that matter).
My best diagnosis of “dizziness” came when I was right out of school. Having no idea, I performed a thorough exam. In the middle of lung auscultation, as I was compulsively checking all fields, the patient stopped taking their deep breaths to exclaim, “My dizziness! It just came back again!” Hyperventilation, due to generalized anxiety. Ask about paresthesias in the hands and lips to clinch the diagnosis.
This isn’t complete, but from now on, we’ll only talk about our current focus: VERTIGO.
The etiology of vertigo will be either:
- Peripheral — vestibular apparatus (labyrinth) of the inner ear (8th cranial nerve)
- Central — brainstem or cerebellum
I wager that virtually all the cases you see will be one of the two most common causes, both peripheral. However, some rare ominous possibilities lurk; our job is to efficiently rule those out. So here’s our differential:
CAUSES OF VERTIGO
| Peripheral | Central |
** Benign Paroxysmal Positional Vertigo (BPPV) — Far and away the most common cause. Ostensibly due to calcium debris in the semicircular canals (labyrinth). Most common >60 y.o., but occurs at any age.
Keys to Diagnosis:
- Occurs only with change of head position
- Duration <1 min. (usually much less)
- Recurrent repetitive attacks, for a median of 2 weeks (may last months)
- No other neuro Sx to suggest a stroke [see below] (nausea / vomiting may occur with any etiology of vertigo)
Physical exam is normal: ENT, Cranial Nerves, Coordination (Cerebellar Function). But the Dix-Hallpike Test is often Positive (click for summary).
Treatment: Might as well do it then and there, with the Epley Maneuver. Goal is to clear the debris. Click for description.
** Acute Labyrinthitis — a.k.a. “Vestibular Neuritis” & other similar terms. Presumed viral, but nobody knows. Patients present with active vertigo & nystagmus [as opposed to the momentary bursts of BPPV, only upon head movement]. The main problem is ruling out Stroke (vertebro-basilar territory: brainstem or cerebellum).
Natural History of Labyrinthitis: severe vertigo for 24-48 hours, which then diminishes significantly, though mild symptoms continue up to a few weeks, and subtle non-specific dizziness or imbalance may persist for months. But that’s no help, because you don’t want to sit on a stroke for 24-48 hours.
Both Stroke and Labyrinthitis begin abruptly. Both cause nystagmus. Never diagnose Labyrinthitis if there is any suggestion of Stroke:
SUGGESTION OF STROKE AS CAUSE OF VERTIGO
Stroke Risk Factors
|
Signs of Vertebro-Basilar Stroke on Exam
|
By the way, DON’T say “nystagmus” if it’s only present on far-lateral gaze. That’s normal; physiologic for everyone. It’d be like charting, “Nose: 2 nostrils present.” “Nystagmus” means it’s present while focusing straight, or with the least little bit of horizontal eye movement.
Special Note: One study found that in the patient with acute vertigo & active nystagmus (objectively seen in the office), suggestive findings in either the hHT or one of 2 other bedside tests were 100% sensitive & 96% specific in distinguishing Vestibular from Central disease, better than an MRI in the first 48 hours! Click here for summary & link (same link as in Table).
I spent a lot of time searching PubMed for information on how often Stroke presents with isolated vertigo (& no other symptom). Seems to be around 1%, which is very reassuring. So if you inquire about other vertebro-basilar symptoms and perform a solid neuro exam, you should be fine. Patient too.
** Transient Ischemic Attack (brainstem or cerebellum) — Say a patient came in with an episode or more of recent vertigo, but now they’re fine. Exam will be normal, the above tests won’t help at all. Who do you work-up?
- Patients with risk factors (see above)
- Patients with a convincing history of Stroke Symptoms during the attack (see above)
What’s the work-up? MRI for signs of having had a stroke. But more important, MR or CT Angiogram, to see if there’s vertebro-basilar insufficiency that’ll cause another TIA, or worse.
First time I did this, I ordered a “Brain MRI & MRA.” Radiology obeyed, & concluded, “looks like a likely stenosis upstream.” So from now on, I order “MRI brain. MRA head & neck.” The “brain” image rules out stroke and finds basilar artery stenosis, the “neck” study captures the vertebral artery.
Don’t order a carotid ultrasound. That’s good for middle cerebral artery territory — hemiparesis, aphasia, sudden monocular blindness (amaurosis fugax). But not for the posterior circulation (vertigo & other brainstem / cerebellar symptoms).
Unfortunately, there’s no endarterectomy-like option for posterior TIAs. Risk-factor control is the mainstay of therapy. If a patient with known vertebro-basilar insufficiency passes out, tell family to have the ambulance rush them to the nearest stroke center (not ER) for heroic embolectomy.
** Multiple Sclerosis — Up to 50% of people with MS have vertigo, but rarely is it the presenting symptom. Maybe that’s because they all get diagnosed with “Labyrinthitis”???
MS is a clinical diagnosis, defined by dysfunction in at least two different central nervous system pathways:
- episodes are separated in time
- deficits resolve at least partially
So Vertigo would be one episode. Don’t worry about MS in the midst of acute vertigo. But once it has resolved, assuming the patient is youngish (20-40), not stroke age, see them back in follow-up. Then inquire about past episodes, lasting at least 24 hours, of other neurological symptoms typical for MS:
- Sensory symptoms: paresthesias, numbness, coldness, etc.
- Uthoff Phenomenon: sensory Sx ↑ w/ heat (fevers, hot showers)
- Lhermitte’s Sign: electric shock runs down body upon neck flexion
- Visual disturbances, w/ or w/o eye pain (optic neuritis)
- Double vision
- Weakness in just one part of the body, especially if disturbed gait
- Urinary incontinence / retention (exaggerated)
Do a targeted physical exam, looking for residua in any symptoms that might have been mentioned (e.g. decreased pinprick wherever sensory symptoms may have been felt). Be sure to include an ocular fundoscopic (for Optic Atrophy: unilateral pallor of the optic disk), and check the pupils for an Afferent Pupillary Defect.
Send to Neuro if suspicious. The diagnosis of MS has life-long implications, and treatment decisions early-on are very tricky.
We’ll discuss Migrainous Vertigo later. We’ve already covered a lot for today. Next posting Vertigo – 2, we’ll go into other Peripheral causes, and summarize our overall approach.
DiagnosisDude 