A 38-year-old woman presents to the emergency department with a 24-hour history of severe, room-spinning dizziness, nausea, and multiple episodes of non-bilious emesis. She reports that the symptoms began suddenly yesterday morning and are significantly worsened by any head movement. She denies any associated hearing loss, tinnitus, or sensation of fullness in her ears. She also denies headache, double vision, or limb weakness, though she notes she had a mild upper respiratory infection approximately two weeks ago. Past medical history is otherwise negative. Vital signs are within normal limits. On physical examination, the patient appears distressed and is leaning toward the right side while sitting. There is spontaneous, horizontal-torsional nystagmus that beats toward the left. The intensity of the nystagmus increases when the patient looks toward the left and is suppressed by visual fixation. A head-thrust test reveals a corrective saccade when the head is rapidly turned toward the right. Hearing is found to be preserved bilaterally on finger rub and Weber and Rinne testing. Neurological examination, including finger-to-nose and heel-to-shin testing, is otherwise unremarkable.
Which of the following is the most likely diagnosis?
The correct answer is:
E) Vestibular neuritis
The patient is presenting with vestibular neuritis, an inflammation of the vestibular nerve (CN VIII), often following a viral prodrome. It is characterized by the sudden onset of continuous, severe vertigo, nausea, and gait instability. On physical examination, patients exhibit signs of a peripheral vestibulopathy with spontaneous horizontal nystagmus (beating away from the affected side) and a positive head-thrust test. A key diagnostic feature that distinguishes vestibular neuritis from other peripheral causes is the absence of auditory symptoms such as hearing loss or tinnitus. The leaning toward the affected side (the side of the lesion) and the corrective saccade during the head-thrust test also points to a right-sided vestibular deficit.
Answer choice A: Benign paroxysmal positional vertigo, is incorrect. Benign paroxysmal positional vertigo (BPPV) presents with brief, episodic vertigo (usually lasting less than one minute) triggered specifically by changes in head position, such as rolling over in bed. It does not cause the continuous, prolonged vertigo seen in this patient.
Answer choice B: Labyrinthitis, is incorrect. Labyrinthitis involves inflammation of both the vestibular and cochlear branches of CN VIII. While it presents with continuous vertigo similar to vestibular neuritis, it is characterized by acute sensorineural hearing loss, which is absent in this case.
Answer choice C: Meniere disease, is incorrect. Meniere disease presents with a classic triad of episodic vertigo lasting 20 minutes to several hours, sensorineural hearing loss, and tinnitus or aural fullness. The continuous nature of this patient's symptoms and the lack of auditory changes make this diagnosis unlikely.
Answer choice D: Vertebrobasilar stroke, is incorrect. A central cause of vertigo, such as a posterior circulation stroke, must always be considered. However, central vertigo typically presents with "D" symptoms (dysarthria, dysphagia, diplopia, dysmetria) and nystagmus that is vertical or direction-changing. This patient’s nystagmus is suppressed by visual fixation, and her cerebellar testing is normal, which is highly suggestive of a peripheral rather than central etiology.
Key Learning Point
Vestibular neuritis is a peripheral vestibular disorder presenting with acute, continuous vertigo and a positive head-thrust test, typically following a viral illness. It is differentiated from labyrinthitis by the preservation of hearing, and from central vertigo (e.g., stroke) by the absence of focal neurological deficits and the suppression of nystagmus with visual fixation. Initial management is symptomatic with antiemetics and vestibular suppressants (e.g., meclizine) for the first 24–48 hours, followed by early mobilization and vestibular rehabilitation.
