Abstract
RATIONALE: Characteristic nystagmus often predicts a responsible lesion and aids in the differential diagnosis of dizziness or vertigo. Upbeat-torsional nystagmus usually presents with posterior canal benign paroxysmal positional vertigo, which occurs after a few seconds of latency following a change in head position. However, it can also be observed in patients with central lesions. This case report aims to highlight the importance of neurologically examining characteristic nystagmus in detecting central lesions. PATIENT CONCERNS: A 56-year-old woman suddenly developed dizziness. Neurological examinations revealed torsional nystagmus with a mild upbeat component that was not triggered by head position changes. No other neurological manifestations were present. DIAGNOSIS: Brain magnetic resonance imaging revealed a left dorsal pontine hemorrhage. INTERVENTIONS: The patient received antihypertensive treatment. Adenosine triphosphate disodium hydrate was administered as a symptomatic treatment for the patient's dizziness. OUTCOMES: The torsional nystagmus gradually decreased in frequency and resolved around the 4th day of hospitalization. The patient was able to walk steadily and was discharged home on the 14th day of hospitalization. LESSONS: Although dizziness with torsional nystagmus is known to be observed in patients with posterior canal benign paroxysmal positional vertigo, when it is sudden, persistent, and occurs independent of head repositioning, central lesions should be considered. Stroke in the brainstem should be considered first, especially in patients with vascular risk factors.