A 61-year-old woman is evaluated in the emergency department for the sudden onset of severe, continuous room-spinning dizziness that began 6 hours ago. The dizziness is present even when she is perfectly still, but it is severely exacerbated by any head movement. She also reports intractable nausea and two episodes of vomiting. Her medical history includes hypertension and hyperlipidemia. Her blood pressure is 154/90 mm Hg, and her pulse is 88/min. She is unable to walk without assistance. On physical examination, the patient is awake and alert. Oculomotor examination reveals spontaneous, horizontal-torsional nystagmus that beats toward the left; the nystagmus increases in amplitude when she looks to the left but does not change direction when she looks to the right. The examiner asks the patient to fixate on a target and rapidly rotates her head to the right; a corrective saccade is observed as her eyes snap back to the target. Rapid head rotation to the left produces no corrective saccade. An alternate cover test reveals no vertical misalignment of the eyes. Otoscopic and hearing examinations are unremarkable. A basic metabolic panel shows a serum sodium of 133 mEq/L and potassium of 3.8 mEq/L. Which of the following is the most appropriate diagnostic interpretation and next step in management based on these physical examination findings?
- The physical examination reliably localizes the lesion to the right peripheral vestibular system; the patient should receive symptomatic medical therapy without the need for urgent neuroimaging.Cevap
- BThe patient's vascular risk factors and profound gait instability supersede the bedside examination, mandating urgent magnetic resonance imaging of the brain to exclude a posterior circulation stroke.
- CThe presence of prominent nystagmus in the setting of acute vertigo is diagnostic of benign paroxysmal positional vertigo; an immediate canalith repositioning maneuver is indicated.
- DThe observation of a unilateral corrective saccade requires the immediate performance of the Dix-Hallpike maneuver to accurately identify the involved semicircular canal.
- EThe clinical presentation is a direct neurologic manifestation of the isolated hyponatremia; targeted intravenous correction of the serum sodium is the primary required intervention.