Optokinetic vertical ocular dysmetria. Divergence nystagmus. Counterolling, pure rotatory positioning nystagmus. Inversion of optokinetic after-nystagmus (OKAN). Vertical congenital nystagmus and inversion of optokinetic nystagmus (OKN). [ncbi.nlm.nih.gov]

Cogan DG: Ocular Dysmetria: Flutter like oscillation of the eyes and opsoclonus. Arch Ophthal 51:318-335, 1954. 8. Goldberg RT. Jampel RS: Flutter like oscillations of the eyes in cerebellar disease. Amer J Ophthal 55:1229-1233, 1963. 9. [healio.com]

Cerebellar Eye Signs: Overview Periodic Alternating Nystagmus Nystagmus Nomenclature Down-beat Nystagmus Chiari Malformation: Eye Movements Up-beat Nystagmus Alexander’s Law Up-beat Nystagmus with Palatal Myoclonus Ocular Palatal Myoclonus Ocular Dysmetria [novel.utah.edu]

Individuals with spinocerebellar ataxia [ 75 ] and Friederich’s ataxia [ 76 ] show a similar pattern of reduced velocity, increased duration and dysmetria as seen in our patients. [molecularautism.biomedcentral.com]

Involvement of the dorsal vermis and fastigial nuclei typically causes saccadic dysmetria and impaired smooth pursuit, which appears “saccadic” on clinical examination. [frontiersin.org]

Vertical spontaneous nystagmus to lower eyelid or so-called "downbeat nystagmus." Downbeat nystagmus seen in bilateral labyrinthine dysfunction. [ncbi.nlm.nih.gov]

These acquired types include: Downbeat nystagmus Upbeat nystagmus Horizontal nystagmus Torsional nystagmus Pendular nystagmus Seesaw nystagmus Vestibular nystagmus Gaze-evoked nystagmus Periodic alternating nystagmus Abducting nystagmus Spasmus nutans [healthhype.com]

Gaze-evoked nystagmus (GEN) as well as downbeat nystagmus (DBN) are also found with cerebellar lesions in MS. [frontiersin.org]

Downbeat Nystagmus Downbeat nystagmus is unusual in children. It is typically worse on lateral gaze and can reflect pathology at the cervicomedullary junction. [aao.org]

Treatment of downbeat nystagmus with 3, 4-diaminopyridine: a placebo-controlled study. Neurology 2003 ; 61 : 165 –70. [jnnp.bmj.com]

According to Duke-Elder3 it is "typical of cerebellar disease." [healio.com]

Greater drop implies deficient VOR gain, though some cases of cerebellar disease have hyperactive VOR (49). The head thrust maneuver tests each horizontal semicircular canal separately (Video “head thrust test” ). [neuroophthalmology.ca]

PubMed Google Scholar Golla H, Tziridis K, Haarmeier T, Catz N, Barash S, Thier P: Reduced saccadic resilience and impaired saccadic adaptation due to cerebellar disease. Eur J Neurosci. 2008, 27: 132-144. [molecularautism.biomedcentral.com]

An increased number of SWJs is seen in cerebellar disease, progressive supranuclear palsy, and multiple system atrophy. During fixation saccadic oscillations and nystagmus should also be noted. [jnnp.bmj.com]

Upbeat Nystagmus Possible causes include damage, disease or disorders of the: Medulla Cerebellum (specifically of the anterior vermis) This type of nystagmus may also occur with benign paroxysmal positional vertigo. [healthhype.com]

Glasauer S, Kalla R, Buttner U, Strupp M, Brandt T. 4-Aminopyridine restores visual ocular motor function in upbeat nystagmus. [frontiersin.org]

Upbeat nystagmus, when present in the primary position, is usually associated with focal brainstem lesions in the tegmental grey matter. The most common causes are multiple sclerosis, tumour, infarction, and cerebellar degeneration. [jnnp.bmj.com]

Optokinetic vertical ocular dysmetria. Divergence nystagmus. Counterolling, pure rotatory positioning nystagmus. Inversion of optokinetic after-nystagmus (OKAN). Vertical congenital nystagmus and inversion of optokinetic nystagmus (OKN). [ncbi.nlm.nih.gov]

Cogan DG: Ocular Dysmetria: Flutter like oscillation of the eyes and opsoclonus. Arch Ophthal 51:318-335, 1954. 8. Goldberg RT. Jampel RS: Flutter like oscillations of the eyes in cerebellar disease. Amer J Ophthal 55:1229-1233, 1963. 9. [healio.com]

Cerebellar Eye Signs: Overview Periodic Alternating Nystagmus Nystagmus Nomenclature Down-beat Nystagmus Chiari Malformation: Eye Movements Up-beat Nystagmus Alexander’s Law Up-beat Nystagmus with Palatal Myoclonus Ocular Palatal Myoclonus Ocular Dysmetria [novel.utah.edu]