NEUROLOGY 2008;70:e96
© 2008 American Academy of Neurology
Resident and Fellow Section
Teaching Video NeuroImage: Acquired or congenital gaze-evoked nystagmus?
Matthew J. Thurtell, MBBS,
Konrad P. Weber, MD and
G. Michael Halmagyi, MD
From the Department of Neurology (M.J.T., K.P.W., G.M.H.), Institute of Clinical Neurosciences, Royal Prince Alfred Hospital and the University of Sydney, Australia; and Department of Neurology (M.J.T.), University Hospitals Case Medical Center, and the Daroff-Dell'Osso Ocular Motility Laboratory, Louis Stokes Department of Veterans Affairs Medical Center, Cleveland, OH.
Address correspondence and reprint requests to Dr. Matthew J. Thurtell, Department of Neurology, Hanna 5040, University Hospitals Case Medical Center, 11100 Euclid Avenue, Cleveland, OH 44106 matthewt{at}icn.usyd.edu.au
A 40-year-old female migraineur reported intermittent unsteadiness with headache. On examination, she had gaze-evoked horizontal-torsional nystagmus that was also evident during pursuit (video). Nystagmus recordings showed increasing-velocity slow phases typical for congenital nystagmus (CN) (figure 1). A relative subsequently confirmed that the nystagmus was long-standing.
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Figure 1 Three-dimensional search-coil recordings of the patient's nystagmus
The patient is attempting to fixate leftward (A), central (B), and rightward (C) targets (Fix), indicated by arrowheads next to the horizontal traces. The traces show leftward-upward-counterclockwise jerk nystagmus (A), alternating-direction horizontal-torsional jerk nystagmus with extended foveation (B), and rightward-upward-clockwise jerk nystagmus with extended foveation (C). Each nystagmus slow phase increases in velocity with time. Positive directions are rightward, upward, and clockwise, as indicated.
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While usually isolated, CN can be associated with visual system abnormalities or strabismus.1 It is usually conjugate, horizontal with a subtle torsional component,2 and minimized in a certain "null" position. Eye movement recordings help differentiate it from other nystagmus types (figure 2).1 Confirmation that it is long-standing supports the diagnosis, helping to avoid unnecessary investigations.
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Figure 2 Typical nystagmus waveforms
(A) Increasing-velocity slow phase waveform typical of congenital nystagmus. (B) Decreasing-velocity slow phase waveform typical of cerebellar gaze-evoked nystagmus. (C) Constant-velocity slow phase waveform typical of vestibular nystagmus. Position of fixation target (Fix) is indicated by arrowheads. While the search-coil technique is the current gold standard, satisfactory eye movement recordings can be obtained using electro-oculography, infrared-, or video-based techniques, often through a neuro-otology or otolaryngology service.
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ACKNOWLEDGMENT
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The authors thank Dr. Louis F. Dell'Osso for reviewing the manuscript and for suggestions.
Supplemental data at www.neurology.org
Supported by Garnett Passe and Rodney Williams Memorial Foundation (K.P.W.).
Disclosure: The authors report no disclosures.
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REFERENCES
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- Leigh RJ, Zee DS. The Neurology of Eye Movements, 4th ed. Oxford: Oxford University Press; 2006.
- Averbuch-Heller L, Dell'Osso LF, Leigh RJ, Jacobs JB, Stahl JS. The torsional component of "horizontal" congenital nystagmus. J Neuro-ophthalmol 2002;22:22–32.[Medline]
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