Table 2.
Common eye movement patterns, their nystagmus characteristics, and typical causes.
| Pattern Types | Nystagmus Characteristics | Typical Cause(s) |
|---|---|---|
| Peripheral Vestibular Patterns | Upbeat-torsional nystagmus triggered by the Dix-Hallpike test and that is transient (lasting <30 seconds) | BPPV (posterior canal)a |
| Dominantly horizontal spontaneous nystagmus (i.e., present in primary gaze during routine gaze testing) that is uni-directional (i.e., never changes direction with gaze shifts or head shaking) but increases in velocity with gaze in the direction of the nystagmus fast phase and decreases with gaze in the opposite direction | Vestibular neuritis (less commonly caused by a central lesion typically associated with other findingsb) | |
| Central Vestibular Patterns | Dominantly vertical (upbeat or downbeat) or torsional spontaneous nystagmus (i.e., present in primary gaze during routine gaze testing) Dominantly horizontal gaze-evoked direction changing nystagmus (i.e., persistent left-beat on left gaze and persistent right-beat on right gaze) Non-fatiguing positional down-beat nystagmus triggered by a positional test such as the Dix-Hallpike test |
Stroke, multiple sclerosis, Chiari malformation, other structural central disorders, medication side effects (e.g., anti-epileptic medications) |
| Physiological Patterns | Few beats of end-gaze nystagmus (non-sustained left beat nystagmus on far left gaze with symmetric right-beat nystagmus on far right gaze) | Normal variant |
BPPV = benign paroxysmal positional vertigo
a
The second most common variant of BPPV is the horizontal canal variant which is characterized by transient horizontal nystagmus (rather than upbeat-torsional nystagmus) triggered by a head turn to either side while lying supine (e.g., head turn to right triggers right-beat horizontal nystagmus, head turn to left triggers left-beat horizontal nystagmus).
b
See Chapters 2, 10, and 11 for information regarding findings suggesting a central vestibular lesion in the presence of uni-directional spontaneous nystagmus.