A 62-year-old woman comes to the emergency department feeling "dizzy." While at a grocery store today, the patient was looking up at a high shelf when she suddenly experienced a spinning sensation accompanied by nausea. She closed her eyes and sat down in the aisle, and the symptoms resolved after about a minute. The patient has had no headache, earache, tinnitus, or hearing impairment. The symptoms recurred 30 minutes later when she bent down to get into her car. Currently, she feels well and has no symptoms. Medical history is significant for hypertension, hyperlipidemia, and type 2 diabetes mellitus. She previously smoked a pack of cigarettes a day but quit 10 years ago. Which of the following is most likely to reveal the underlying cause of this patient's symptoms?

Question

A 62-year-old woman comes to the emergency department feeling "dizzy."  While at a grocery store today, the patient was looking up at a high shelf when she suddenly experienced a spinning sensation accompanied by nausea.  She closed her eyes and sat down in the aisle, and the symptoms resolved after about a minute.  The patient has had no headache, earache, tinnitus, or hearing impairment.  The symptoms recurred 30 minutes later when she bent down to get into her car.  Currently, she feels well and has no symptoms.  Medical history is significant for hypertension, hyperlipidemia, and type 2 diabetes mellitus.  She previously smoked a pack of cigarettes a day but quit 10 years ago.  Which of the following is most likely to reveal the underlying cause of this patient's symptoms?

Quizplus · Accepted Answer

11ec25c8_d592_fefd_bc81_57c03210e95f_MD0003_00 "Dizziness" is a common presenting concern of patients and may represent presyncope, disequilibrium, or vertigo. Vertigo is often described as a spinning sensation and can be due to dysfunction of either the central or peripheral nervous system. Patients with peripheral vertigo typically have shorter episodes, fatigable nystagmus inhibited by gaze fixation, preserved ambulation, and no other central nervous symptoms (eg, headache, diplopia, dysarthria). This patient's brief (<1 min), episodic vertigo triggered by head position changes (eg, looking up, bending down) is consistent with benign paroxysmal positional vertigo (BPPV), the most common cause of vertigo. BPPV is due to crystalline debris (canaliths) in the semicircular canals that disrupt the normal flow of fluid in the vestibular system. This leads to contradictory signaling from the corresponding canals on each side, which is interpreted as a spinning sensation (vertigo). To confirm the diagnosis, the patient's head position is manipulated to cause free canaliths to move in their respective canals and provoke a symptomatic episode. The Dix-Hallpike maneuver is the best-known provocative head positioning maneuver and assesses the posterior semicircular canals. The result is positive if vertigo and nystagmus are triggered as the patient quickly lies back into a supine position with the head rotated 45 degrees. Dix-Hallpike maneuver (Choice A) Some disorders (eg, Ménière disease, labyrinthitis) cause both vertigo and hearing loss, the latter of which would be seen on an audiogram. BPPV affects only the semicircular canals and therefore does not cause hearing loss. (Choice B) Transient ischemic attack or cerebrovascular accident of the posterior circulation (evaluated by MRI) can present as vertigo in an elderly patient; however, these are central causes of vertigo and would be unlikely to cause recurrent, discrete episodes of vertigo. Rarely, mechanical vertebral artery compression at the cervical level can cause vertigo with head movements, but this is much less common than BPPV and is classically associated with tinnitus, blurred vision, and syncope, not seen in this patient. (Choice C) MRI of the internal auditory canals is used to diagnose vestibular schwannoma (acoustic neuroma), which typically presents with unilateral hearing loss. Imbalance is often present but not spinning vertigo. (Choice D) Orthostatic blood pressure measurement can diagnose orthostatic hypotension, which can cause "dizziness" on changing positions. However, orthostatic hypotension typically causes presyncope rather than vertigo. Educational objective: Benign paroxysmal positional vertigo causes brief (<1 min) episodes of vertigo triggered by changes in head position. Triggering an episode by using provocative head positioning maneuvers (eg, Dix-Hallpike) is diagnostic. References: Benign paroxysmal positional vertigo. (http://www.ncbi.nlm.nih.gov/pubmed/30828628)

A 62-Year-Old Woman Comes to the Emergency Department Feeling "Dizzy