Perverted Downbeat Head-Shaking Nystagmus
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Title: Perverted Downbeat Head-Shaking Nystagmus
Authors: Anthony Mai, MD, University of Utah; Meagan Seay, DO, University of Utah
Date: 2/7/2023
Keywords/Main Subjects: Nystagmus
Diagnosis: Perverted downbeat head-shaking nystagmus
Brief Description:
This video illustrates head-shaking-induced vertical nystagmus starting immediately after horizontal head movement and lasting for 49 seconds. This is consistent with perverted downbeat head-shaking nystagmus (pdHSN), which refers to nystagmus occurring in a plane different from that of the vestibular stimulus (i.e. vertical nystagmus when the stimulus was horizontal head shaking). Head shaking nystagmus (HSN) is caused by peripheral, central, or latent tone imbalance of the vestibulo-ocular reflex. pdHSN, conversely, is assumed to be caused by abnormal cross-coupling of the vestibular response attributed to lesions in central vestibular pathways, including the vestibulo-cerebellum. Experimental lesions of the vestibular nuclei have produced pdHSN in monkeys. Etiologies include stroke, multiple sclerosis, multiple system atrophy, cerebellar degenerations, and drug intoxications. Although the patient in this video did not have a brainstem or cerebellar lesion found on a MRI brain scan, her pdHSN was presumed to be caused by a subtle long-standing demyelinating lesion in the setting of previously diagnosed multiple sclerosis. There is currently no established standard treatment for pdHSN, although possible options include baclofen, gabapentin, and benzodiazepines.
Format: mp4
References:
- Strupp M. Perverted head-shaking nystagmus: two possible mechanisms. J Neurol. 2002 Jan;249(1):118-9. PMID: 11954862.
- Leigh, R. John, and Zee, David S. The Neurology of Eye Movements /. Fifth ed. 2015. Contemporary Neurology Ser. Web.
Faculty Approval by: Meagan Seay, DO
Copyright: Copyright Anthony Mai, Meagan Seay, ©2023. For further information regarding the rights to this collection, please visit: http://morancore.utah.edu/terms-of-use/
Identifier: Moran_CORE_126749