Mr. J is a 32-year-old man who comes to your office complaining of dizziness.
What is the differential diagnosis of dizziness? How would you frame the differential?
CONSTRUCTING A DIFFERENTIAL DIAGNOSIS
The differential diagnosis for dizziness is extensive, encompassing diseases of the inner ear, central and peripheral nervous system, cardiovascular system and psychiatric disease. Fortunately, an organized approach greatly simplifies evaluating the dizzy patient. The first step recognizes that most patients who complain of dizziness are actually complaining of 1 of 4 distinct symptoms: vertigo, near syncope, disequilibrium, and ill-defined lightheadedness. Each of these symptoms has its own particular differential diagnosis and evaluation.
The first pivotal step in evaluating the dizzy patient is to clarify which symptom the patient is experiencing, since this limits the differential diagnosis and focuses the evaluation on the appropriate set of diagnostic possibilities for that particular symptom. Therefore, the first and most important pivotal question is “What does it feel like when you are dizzy?” At this point, patients must be given enough time, without interruptions or suggestions, to describe their dizziness as clearly as possible (Figure 14-1). Commonly used descriptions, their precipitants, and differential diagnosis are listed in Table 14-1.
Table 14-1.Classification and characteristics of dizziness. ||Download (.pdf) Table 14-1. Classification and characteristics of dizziness.
| ||Vertigo ||Near Syncope ||Dysequilibrium ||Nonspecific Dizziness |
|Chief complaint ||Spinning or sensation of self motion (when none is occurring) ||Sense of impending loss of consciousness ||Unstable while seated, standing or walking ||Floating, vague |
|Typical precipitants || |
Turning over in bed Looking up to shelf
Moving the head
|Standing ||Walking ||Stress |
|Important historical features || |
CNS signs or symptoms (eg, dysarthria, ataxia, diplopia, headache, neck pain)
Peripheral symptoms (eg, hearing loss, tinnitus)
Syncope during exercise
Melena or rectal bleeding
Multiple somatic complaints
Feeling down or hopeless
|Key physical exam findings || |
Cranial nerve exam
Orthostatic blood pressure and pulse
Cardiac exam for murmur or S3
Cranial nerve exam
|Differential diagnosis || |
Central: Cerebrovascular disease, MS, cerebellar hemorrhage, migraine, brainstem tumors
Multiple sensory deficits
Cerebellar degeneration or stroke
Normal pressure hydrocephalus
Generalized anxiety disorder
Step 1: Approach to the patient with dizziness.
In practice, many patients often have difficulty describing their symptom and have ill-defined lightheadedness. Therefore, the second pivotal ...