Dizziness, Disease, and Doctors' Dizz-Ease

As clinicians, it is obvious that we don't love dizziness.

Not that we have a problem with the idea of it in general.  It's just that it's so.... common.  Vague.  Banal.  Potentially worrisome.  Hard to understand.  Harder to approach.  Tempting to investigate to the nth degree, with an array of tests that's, well, dizzying, and may well leave you just where you started.  Unsure of what is going on, and your dizzy patient is no better off.


Anybody feeling their head spin yet?

Yet we get referred dizzy patients all the time.  In General Medicine, they usually come with the additional label of "R/O [insert ominous disease here]".  Alarming, except that we know that most dizzy patients have a benign underlying diagnosis - in the sense that their symptoms don't connote a life-shortening underlying disease.  How do we sort this out?

We discussed an approach which tries to maximize the value of information that is already at hand.

First, classify the dizziness into one of 4 basic syndromes:

• Presyncope - the feeling of impending faint.  Look for tunnel vision, "dissociated" hearing, blood pressure changes, orthostatic symptoms, vagal stimuli.
• Vertigo - the illusion, often visual, that the person or the environment is rotating.  Note, patients are aware that this is an illusion!
• Dysequilibrium - patient describes the inability to remain upright, tendency to fall or stumble, feeling as if intoxicated or walking on the deck of a ship at sea.  This is really the subjective feeling of ataxia.
• Ill-defined lightheadedness - a grab bag of other descriptions.  Note, this could include patients who belong in the other 3 categories but you didn't understand their story well!

Next, look for the association:

• Presyncope usually connotes a cardiovascular cause - changes in BP
• Vertigo can be central or peripheral - see below
• Dysequilibrium is often a disorder of cerebellar coordination, dorsal columns or peripheral nerves responsible for proprioception

The following article helps to go over these possibilities:

Differential diagnosis of dizziness (U of T link)

In addition, the more difficult problem of analyzing dizziness in older patients is addressed in this 2 part series:

Dizziness in the older adult, Part 1. Evaluation and general treatment strategies (U of T link)

Dizziness in the older adult, Part 2. Treatments for causes of the four most common symptoms  (U of T link)

When vertigo is the best description of the patient's complaint, the key is to distinguish central from peripheral causes.  Bottom line:

• Peripheral causes of vertigo usually have very well defined presentations, which often match classic descriptions - the prototype for this is BPPV.
• Peripheral causes are very unlikely to be associated with non-horizontal nystagmus.  Note, central causes can be associated with any type of nystagmus.
• Autonomic symptoms are more common with many peripheral causes of vertigo.
• The response to the Dix-Hallpike manoeuvre is usually immediate, dramatic, and fatigues rapidly in peripheral causes of vertigo.

This article takes a statistical approach - what is this likely to be?  Note they focus on what presents in ER, rather than on a general population.

An approach to dizziness and vertigo in the emergency department (U of T link)

And what about central causes?  They are what we really worry about, yet we don't usually have a good approach to them, apart from "get an MRI".  This article goes over these issues.

Central vertigo and dizziness: epidemiology, differential diagnosis, and common causes (U of T link)

Finally, what to do about it?

Here is a very useful article about BPPV .  (U of T Link)  Otherwise, see the link above for treatment of symptoms in dizzy patients in general.

Finally, here is a YouTube animated video of the Dix Hallpike manoeuvre and the associated Epley's manoeuvre which treats BPPV specifically.