By Marcello Cherchi, MD PhD
For patients
Spontaneous up beat nystagmus is an eye movement that can occur with disease, though can also be found in some apparently normal persons. If your doctor identifies spontaneous up beat nystagmus, they may consider checking several tests or doing brain imaging.
For clinicians
Overview
Spontaneous up beat jerk nystagmus (SUBJN) on primary position of gaze often reflects pathology, but can also occur in some otherwise apparently normal individuals. The mechanism of SUBJN is unclear, and may vary depending on the underlying pathology. SUBJN is sometimes suppressed by visual fixation and thus may not be evident on face-to-face examination, only becoming apparent under infrared video oculography.
Introduction
Spontaneous up beat jerk nystagmus (SUBJN) is an abnormal eye movement in which on primary position of gaze, the patient’s eyes slowly drift down, and then snap back up, and the cycle repeats.
Pathophysiological mechanism of disease
The mechanism of spontaneous up beat nystagmus is unclear, and may vary depending on the disease in question. For example, some investigators suspect that the spontaneous up beat nystagmus found with nicotine is due to an influence on the vestibular ocular reflex (Pereira et al. 2000; Pereira et al. 2001).
Clinical presentation
The clinical presentation depends on the underlying disease (see below on differential diagnosis).
Oculomotor examination
Leigh and Zee (Leigh and Zee 2015) make the following general observations about spontaneous up beat nystagmus:
- Unlike spontaneous down beat nystagmus, up beat nystagmus does not usually increase on lateral gaze.
- Up beat nystagmus that is present in central position usually follows Alexander’s law, becoming greatest in up gaze. Sometimes, however, the nystagmus is accentuated on looking down, and then the slow phase is more likely to be increasing-velocity rather than linear.
- Prevention of visual fixation (e.g., by using infrared goggles) may alter the frequency of quick phases but usually does not influence slow-phase velocity.
- Convergence enhances the nystagmus in some patients, suppresses it in others, and converts it to down beat nystagmus in others.
Testing: vestibular
Spontaneous up beat nystagmus may be suppressed by visual fixation, and only become apparent when a patient is examined under infrared video oculography.
Differential diagnosis
Spontaneous up beat nystagmus is uncommon, and its differential diagnosis is somewhat broad. The following list is adopted from Leigh and Zee (Leigh and Zee 2015).
- Infarction of medulla, pontomesencephalic junction, or superior cerebellar peduncle
- Wernicke’s encephalopathy
- Multiple sclerosis
- Tumors of the medulla
- Ataxia telangiectasia
- Cerebellar degeneration
- Brainstem encephalitis
- Creutzfeldt-Jacob disease
- Cerebellar vermis tumor
- Paraneoplastic phenomenon
- Associated with anti-Ma2 antibodies
- Meningitis
- Associated with anti-GAD antibodies, including stiff-person syndrome
- Leber’s congenital amaurosis and other congenital disorders of the anterior visual pathways
- Tobacco and nicotine
- Organophosphate poisoning and organoarsenic poisoning
- Transient finding in infants
- Can be found in some normal adults
Our clinical experience is that spontaneous up beat nystagmus is most commonly encountered in association with nicotine (Kim et al. 2000; Pereira et al. 2001; Sibony, Evinger, Manning 1987).
Treatment and prognosis
Treatment and prognosis of spontaneous up beat nystagmus depends on the underlying cause. Glasauer and colleagues report that 4‑aminopyridine may improve fixation suppression of spontaneous up beat nystagmus (Glasauer et al. 2005).
References
Glasauer S, Strupp M, Kalla R, Buttner U, Brandt T (2005) Effect of 4-aminopyridine on upbeat and downbeat nystagmus elucidates the mechanism of downbeat nystagmus. Ann N Y Acad Sci 1039: 528-31. doi: 10.1196/annals.1325.060
Kim JI, Somers JT, Stahl JS, Bhidayasiri R, Leigh RJ (2000) Vertical nystagmus in normal subjects: effects of head position, nicotine and scopolamine. J Vestib Res 10: 291-300.
Leigh RJ, Zee DS (2015) The neurology of eye movements, 5th edn. Oxford University Press, Oxford ; New York
Pereira CB, Strupp M, Eggert T, Straube A, Brandt T (2000) Nicotine-induced nystagmus: three-dimensional analysis and dependence on head position. Neurology 55: 1563-6.
Pereira CB, Strupp M, Holzleitner T, Brandt T (2001) Smoking and balance: correlation of nicotine-induced nystagmus and postural body sway. Neuroreport 12: 1223-6.
Sibony PA, Evinger C, Manning KA (1987) Tobacco-induced primary-position upbeat nystagmus. Ann Neurol 21: 53-8. doi: 10.1002/ana.410210110
