(DRG) Departments of Neurology, Ophthalmology, Neurosurgery, Otolaryngology - Head & Neck Surgery, Emergency Medicine, and Medicine, The Johns Hopkins School of Medicine, Baltimore, Maryland
Subject
Voluntary nystagmus; Ocular flutter
Description
Despite its name, this movement is not technically a form of nystagmus in the absence of slow phases. Instead, it is more reminiscent of ocular flutter given back-to-back horizontal saccades without an intersaccadic interval. While ocular flutter is often due to dangerous etiologies, voluntary nystagmus is often functional or a "party trick" (which it was for this patient). The ability to volitionally produce these movements often runs in families. Benign voluntary nystagmus can be diagnosed and distinguished from potentially dangerous ocular flutter when the following are present: association with eyelid fluttering; inability to sustain movements for greater than a few seconds; activation of the near triad is often necessary to produce the movements, so convergence effort and miosis can be appreciated; absence of central ocular motor signs or neurologic abnormalities and a long duration of symptoms (e.g., months to years).
