“Dizziness” is a nonspecific term often used by patients to describe symptoms. The most common disorders lumped under this term include vertigo, nonspecific “dizziness,” disequilibrium, and presyncope. The first and most important step in the evaluation is to fit the patient into one of these more specific categories.
The evaluation of vertigo and presyncope (the evaluation of which is the same as the syncope evaluation) are can be reviewed at the Critical Care Assessment pages
Dizziness is a feeling that may be hard to describe, but often includes a feeling that you are spinning or tilting, or that you are about to fall or pass out. Dizziness can also cause you to feel lightheaded or giddy, or have difficulty walking straight.
Many people who feel dizzy have vertigo, a specific type of dizziness. Vertigo causes a sense of spinning dizziness, swaying, or tilting. You may feel that you are moving or that the room is moving around you. Vertigo can be caused by a number of different problems involving the inner ear or brain. Some of these problems are not serious while others can be life threatening.
Vertigo is a symptom of illusory movement. Almost everyone has experienced vertigo as the transient spinning dizziness immediately after turning around rapidly several times. Vertigo can also be a sense of swaying or tilting. Some perceive self-motion whereas others perceive motion of the environment.
Vertigo is a symptom, not a diagnosis. It arises because of asymmetry in the vestibular system due to damage to or dysfunction of the labyrinth, vestibular nerve, or central vestibular structures in the brainstem.
Vertigo is a troubling problem for many clinicians because it is symptomatic of a large range of diagnoses from benign to immediately life threatening. However, in most cases, the clinical history, especially the tempo of the symptoms, with examination findings that distinguish between central and peripheral etiologies identify those patients that require urgent diagnostic evaluation.
Vertigo is only one type of dizziness. Other disorders that present with dizziness include presyncopal faintness, disequilibrium, and nonspecific or ill-defined light-headedness. The initial approach to the patient who complains of dizziness is to localize the cause of the symptom into one of these broad categories. This is described separately.
The most common symptoms of vertigo include a feeling of:
These feelings come and go, and may last seconds, hours, or days. Patients may feel worse when they move their head, change positions (stand up, roll over), cough, or sneeze. Along with vertigo, you may:
If you seek treatment for vertigo, you should mention how long these symptoms last, what triggers the symptoms, and any other associated problems. These clues can help point to the cause of vertigo.
COMMON CAUSES OF VERTIGO
The most common causes of vertigo include:
The vestibular system is the system of balance and equilibrium. The vestibuloocular reflex (VOR) forms the basis for many of the clinical tests used to evaluate balance function. The vestibular system controls reflexes that maintain stable vision and posture.
Vestibular function tests are tests of function. The tests are used to determine potential causes of balance disturbances, and they tests help to determine if there is a problem with the vestibular portion of the brainstem and inner ear. The balance system depends on the inner ear, the eyes and the muscles and joints to send information related to the body’s movement and orientation in space. When there are problems with the inner ear or other parts of the balance system, the patient may present with symptoms of vertigo, dizziness, imbalance or other symptoms.
Indications for vestibular function testing include:
A complete picture of the patient is necessary to determine if diagnostic testing is warranted. A complete history, physical exam and review of medications must be performed before ordering diagnostic tests.
By performing the history and physical and medication review, the physician can often differentiate between vestibular and non-vestibular dizziness. The differentiation of the two is important because true spinning vertigo is often inner ear related and non-vertigo symptoms may be due to inner ear problems as well as CNS, cardiovascular, or systemic diseases or by medications that cause cardiovascular, CNS or ototoxic symptoms. In the case where it is clearly evident that the symptoms are non-vestibular in nature, then vestibular testing should not be done. However, if the physician cannot definitively differentiate between the two and feels vestibular testing is justified, then the medical record should clearly support the need to proceed with vestibular testing.
Evaluating the VOR requires application of a vestibular stimulus and measurement of the resulting eye movements. Quantitative test of physiological processes under vestibular control can be useful in identifying the cause of the patient’s symptoms, confirming findings noted on the history and physical exam, planning therapeutic interventions and monitoring the response to those interventions.
A standard vestibular function test battery includes 1.) tests of visual ocular control; 2.) a careful search for pathologic nystagmus with fixation and with eyes open in darkness and with 3.) measurement of induced physiologic nystagmus.