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  The patient’s definition of “dizziness” must be clarified with a careful and explicit history taken by the health care provider.

  
  
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  True vertigo must be differentiated from other types of dizziness.

  
  
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  Attempt to distinguish peripheral from central vertigo.

  
  
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  Consider life-threatening causes of dizziness such as cardiac syncope and cerebellar infarct or hemorrhage in all patients, especially the elderly.

Dizziness is one of the most common emergency department (ED) presentations and one of the most difficult to characterize. Dizziness means different things to different people and crosses language and cultural boundaries. The precise definition ranges from weakness, giddiness, and anxiety to true vertigo, presyncope, disequilibrium, or nonspecific lightheadedness. A very careful history from the patient, friends, or family is the most important part of the initial evaluation of the dizzy patient.

Dizziness can be divided into 4 main types: vertigo, presyncope, disequilibrium, and lightheadedness. Vertigo is defined as the perception of movement where no movement exists. Patients often describe feeling the room spinning. It can be further divided into central and peripheral types. Peripheral vertigo is usually benign and caused by an inner ear problem, whereascentral vertigo is usually serious and involves pathology within the cerebellum or brainstem. Presyncope is defined as lightheadedness derived from feeling an impending loss of consciousness. Disequilibrium refers to a feeling of unsteadiness, imbalance, or a sensation of floating while walking. Lightheadedness is the most difficult type of dizziness to characterize. Many patients in this group have vague, poorly defined symptoms, such as just not feeling right, that do not fall into one of the other categories.

The central nervous system (CNS) coordinates and interprets sensory inputs from visual, vestibular, and proprioceptive systems. These 3 systems give us the sense of position in our 3-dimensional universe. The disruption of any 1 of these 3 can produce vertigo. The most common forms of vertigo involve dysfunction of the vestibular apparatus and are thus considered peripheral vertigo. By far the most common cause of vertigo is benign paroxysmal positional vertigo (BPPV), which is caused by a mechanical disorder of the inner ear. It is due to the accumulation of floating calcium carbonate particles in either the left or right semicircular canals. These particles stimulate the labyrinth, causing asymmetric input from the normal and affected semicircular canals, which produces the sensation of vertigo. Clinically, BPPV is characterized by vertigo precipitated by certain head movements, which aggravate this unilateral dysfunction. Other causes of peripheral vertigo include Ménière disease, labyrinthitis, and vestibular neuronitis. Ménière disease is a disorder in which there is an increase in volume and pressure of the endolymph of the inner ear, eventually leading to damage of the endolymphatic system and deafness. The pathophysiology of labyrinthitis is not completely understood, although many cases are associated with systemic or viral illnesses, which is thought to cause inflammation in the vestibular apparatus. Viral infection of the vestibular nerve is believed to be the most common cause of vestibular neuronitis.

Central vertigo is much less common than peripheral vertigo and is due to CNS dysfunction. Cerebellar infarct or hemorrhage, cerebellopontine angle tumors and schwannomas, and vertebrobasilar insufficiency frequently cause central vertigo symptoms.

History

The cause of dizziness can be elicited by history alone in more than half of all cases. Patients with vertigo complain of a sensation of movement, or “the room spinning” around them, with associated nausea and vomiting. BPPV usually has an abrupt onset, lasts <1 minute, and is provoked by head movement. ED physicians should be aware that some causes of central vertigo such as vertebrobasilar insufficiency (VBI), transient ischemic attack, and cerebellar hemorrhage may also have an acute onset. Ménière disease is associated with hearing loss and tinnitus, and the vertigo usually lasts for hours. The vertigo caused by labyrinthitis and vestibular neuronitis usually lasts for a few days. In contradistinction, the symptoms of central vertigo are usually less acute, more persistent, and may have associated neurologic symptoms (Table 81-1).

Patients with presyncope often complain of feeling as though they are going to pass out. This may be associated with a stressful event (vasovagal episode), exertion (aortic stenosis), sudden change in posture (hypovolemia), or palpitations (dysrhythmia). Disequilibrium is most often a complaint of elderly patients. Their sense of loss of balance is usually worse at night (limited visual acuity is further impaired) and later in the day (more fatigued). Patients with lightheadedness usually have vague complaints. Past medical history and associated chronic medical conditions should be ascertained in an attempt to find a cause for their complaints.

Physical Examination