Central Cause of Vertigo: Physical Examination Findings
Right-beating nystagmus on lateral gaze is the most concerning finding for a central cause of vertigo in this patient with sudden onset of persistent symptoms.
Key Distinguishing Features of Central vs. Peripheral Vertigo
Nystagmus Patterns That Indicate Central Pathology
The nystagmus characteristics are critical for distinguishing central from peripheral causes:
- Direction-changing nystagmus without changes in head position is a hallmark of central vertigo, meaning the nystagmus changes direction with gaze (e.g., right-beating when looking right, left-beating when looking left) 1
- Pure vertical nystagmus (upbeating or downbeating) without a torsional component strongly suggests a central lesion 1, 2
- Gaze-evoked or gaze-holding nystagmus that persists in different gaze directions is typical of central pathology 3, 1
- Baseline nystagmus present without provocative maneuvers indicates a central cause 3, 1
- Nystagmus that is NOT suppressed by visual fixation points to central pathology 1, 4
Analysis of the Presented Options
Corrective saccade with head rotation (Option 1): This describes a positive head impulse test, which indicates peripheral vestibular dysfunction, not central 5. When the vestibulo-ocular reflex is impaired peripherally, corrective saccades are needed to refixate on a target.
Eye deviation with cover-uncover test (Option 2): This describes a skew deviation, which is part of the HINTS examination and can suggest central pathology 5. However, this finding alone has lower specificity compared to certain nystagmus patterns.
Right-beating nystagmus on lateral gaze (Option 3): This is direction-changing, gaze-evoked nystagmus - a classic central finding 1, 2. If the nystagmus beats in the direction of gaze (right-beating when looking right, presumably left-beating when looking left), this indicates central pathology requiring urgent evaluation.
Vertigo with Dix-Hallpike maneuver (Option 4): This describes a peripheral cause (BPPV). Peripheral BPPV produces torsional and upbeating nystagmus with latency (5-20 seconds), crescendo-decrescendo pattern, and resolution within 60 seconds 6, 1.
Red Flags Requiring Urgent Neuroimaging
In a patient with sudden onset of persistent vertiginous symptoms, the following findings mandate immediate evaluation for stroke:
- Downbeating nystagmus on Dix-Hallpike without torsional component 1, 7
- Direction-changing nystagmus without head position changes 3, 1
- Severe postural instability with inability to stand or walk 1
- Nystagmus that does not fatigue with repeated testing 1, 4
- Associated neurological symptoms such as dysarthria, dysphagia, diplopia, or focal motor/sensory deficits 1
Critical Clinical Context
The description of "sudden onset of persistent" symptoms is particularly concerning, as this suggests acute vestibular syndrome rather than episodic BPPV 1. Approximately 25% of patients presenting with acute vestibular syndrome have cerebrovascular disease, rising to 75% in high vascular risk cohorts 3. Importantly, focal neurologic deficits may be absent in one-third to two-thirds of stroke patients with vertigo 3, 7.
Common Pitfall to Avoid
Do not assume that absence of focal neurologic deficits rules out stroke - up to 80% of patients with stroke-related acute vestibular syndrome may have no associated focal neurologic deficits 3. The nystagmus pattern and HINTS examination are more sensitive than early MRI (100% vs. 46% sensitivity when performed by trained practitioners) 3.