Vertigo and Dizziness
Because many health conditions can cause dizziness, physicians must systematically exclude diagnostic possibilities during evaluation of patients who present with dizziness. Ruling out urgent causes of vertigo and dizziness, such as stroke, is vital (Kerber 2009b; Tarnutzer 2011; von Brevern 2015; Lin 2013). Sudden onset of severe dizziness accompanied by neurologic symptoms such as numbness or weakness of a limb or the face, difficulty swallowing, or speech or language difficulties may indicate stroke (Wetmore 2013).
Usually, the initial differential diagnosis involves ruling out the most common causes of dizziness, such as positional vertigo and orthostatic hypotension. If the cause of dizziness is not then immediately obvious, physicians may try to categorize each case to facilitate further diagnostic precision. Categories (Table 2) of dizziness include vertigo, pre-syncope, disequilibrium, and lightheadedness (Susanto 2014; Post 2010; Samuels 2010; Hogue 2015). A newer approach has been proposed as well, based upon the timing and triggers of dizziness (Edlow 2016). This strategy groups cases into one of three categories: vestibular syndrome, common benign causes (eg, positional vertigo), and dangerous causes (eg, stroke).
The patient’s eyes are often helpful in the evaluation of dizziness. Nystagmus (involuntary, rapid eye movements) may manifest differently depending on the cause of dizziness; diligent clinicians may be able to rule out certain causes of dizziness upon observation of the pattern of nystagmus or other eye movement abnormalities (Edlow 2016). However, the utility of this approach depends in large part on the level of physician knowledge and also the time he or she takes in evaluating the patient.
A specialized maneuver called the Dix-Hallpike test utilizes rapid head rotation while moving from a seated to lying position, and may help diagnose positional vertigo. If the maneuver recreates vertigo and a particular pattern of nystagmus, it points to positional vertigo as the cause (AHRQ 2014; Vanni 2014).
Blood tests are generally not necessary in the diagnosis of dizziness and vertigo, though they may help detect abnormalities such as anemia, infection, and thyroid or autoimmune disease. Additional diagnostic tests such as MRI and CT scans are indicated when central causes are suspected, while hearing tests may help differentiate among possible causes of vertigo (Vanni 2014; AHRQ 2014; Strupp 2008; Wetmore 2013).