Table 3.
Nystagmus characteristics in key peripheral and central vestibular disorders
| Vestibular Condition | Test Maneuver | Nystagmus Duration | Trajectory/Direction | Variation in Direction |
|---|---|---|---|---|
| Triggered Episodic Vestibular Syndrome* (episodic nystagmus triggered by specific positional maneuvers) | ||||
| posterior canal BPPV | head hanging with 45° turn to each side (Dix-Hallpike) | 5–30 seconds † | upbeat-torsional ‡ | direction reversal on arising |
| horizontal canal BPPV | supine roll to either side (Pagnini–McClure) | 30–90 seconds † | horizontal | spontaneous reversal during test |
| central paroxysmal positional vertigo | any (usually head hanging) | 5–60+ seconds † (sometimes persistent if position is held) | any (usually downbeat or horizontal) | any (often direction-fixed) |
| Spontaneous Acute Vestibular Syndrome* (spontaneous nystagmus that may be exacerbated non-specifically by various head maneuvers) | ||||
| vestibular neuritis or labyrinthitis | gaze testing § | persistent | dominantly horizontal | direction-fixed (acutely) |
| stroke | gaze testing § | persistent | any (usually dominantly horizontal, occasionally vertical or torsional) | direction-fixed or direction-changing with gaze position |
Abbreviations: BPPV – benign paroxysmal positional vertigo
Key – green – very likely peripheral nystagmus; red – very likely central nystagmus; black – indeterminate nystagmus (other eye movement features may be diagnostic)
Only two syndromes (t-EVS, s-AVS) are shown in this table because the other two syndromes (s-EVS, t-AVS) lack characteristic, diagnostic patterns of nystagmus.
BPPV nystagmus usually begins after a delay (latency) of a few seconds, peaks in intensity rapidly, then decays monophasically as long as the head is held stationary. In the horizontal canal variant, the nystagmus may be biphasic, with a spontaneous direction reversal after the initial nystagmus, even if the head is held motionless. Central paroxysmal positional vertigo may begin immediately or after a delay, may decay or persist, and may or may not change direction during testing.
Torsion with the 12 o’clock pole (top) of the eye beating towards down-facing (tested) ear, sometimes referred to as ‘geotropic’ (i.e., towards the ground).
In the acute vestibular syndrome, gaze testing is useful but positional tests are not. With peripheral lesions, nystagmus should increase in intensity when the patient’s gaze is directed towards the fast phase of the nystagmus, and should not reverse. With central lesions, this same pattern may occur, but more than one third of the time, the nystagmus will reverse direction when the patient’s gaze is directed away from the fast phase of the nystagmus (i.e., is ‘direction-changing’ with gaze position).