Mr. D is a 40-year-old white man who complains of dizziness. His past medical history is unremarkable except for controlled hypertension. Detailed questioning reveals that he has had a constant spinning sensation for the last 3–4 days. He has no history of similar episodes or hearing loss. Although head movement exacerbates the symptom, it is persistent even when he is still.
At this point, what is the leading hypothesis, what are the active alternatives, and is there a must not miss diagnosis? Given this differential diagnosis, what tests should be ordered?
RANKING THE DIFFERENTIAL DIAGNOSIS
As noted in the beginning of the chapter the first pivotal point in dizzy patients distinguishes vertigo from near syncope or dysequilibrium (see Figure 14-1). Clearly, Mr. D is suffering from vertigo. The second step searches for CNS signs or symptoms that might suggest central vertigo (Figure 14-3). This requires a careful neurologic history and exam searching for cranial nerve or cerebellar findings.
Mr. D denies any history of significant headaches. He denies any history of prior or current neurologic complaints, such as diplopia, visual loss, ataxia, or unexplained motor or sensory symptoms. He does note some intermittent nausea. On physical exam his vital signs are BP, 126/82 mm Hg; pulse, 74 bpm; RR, 16 breaths per minute; temperature, 37.0°C. HEENT exam reveals that his pupils are equal, round, react to light and accommodation. Extraocular movements are intact. Neurologic exam reveals normal gait, motor strength, sensation, negative Romberg sign, and intact cranial nerves.
Mr. D has no obvious symptoms or signs to suggest central vertigo. As noted above, the next step in vertiginous patients without obvious CNS symptoms or signs is to review the time course of the vertigo as well as its trigger to determine the appropriate evaluation and differential diagnosis (see Figure 14-3).
Mr. D repeats that his vertigo has been present for days. He reports that head motion makes it worse, but that it is also present even while he is still. He has never had any prior similar episodes.
Unlike our first patient Mr. J, Mr. D has vertigo that is continuous, lasting for days and spontaneous (that is present even without head motion). Patients with a single prolonged episode (days) of spontaneous vertigo (present without motion) are classified as having the acute vestibular syndrome. Its differential diagnosis includes vestibular neuritis, stroke, and other CNS causes (ie, MS). Of these, vestibular neuritis is the most common and the leading hypothesis. Mr. D’s history of hypertension increases his risk of stroke, but his young age makes it less likely. He has not had any prior symptoms suggestive of MS (eg, diplopia, dysarthria, weakness) but this could still represent his initial presentation. Additionally, he has no history of cancer making metastatic disease unlikely but a primary CNS neoplasm ...