Research advances on mechanism and lesion location of vertical nystagmus / 临床耳鼻咽喉头颈外科杂志

Summary@#Vertical nystagmus is a vertical nystagmus caused by structural abnormalities and/or dysfunction of the central vestibular system and observed in situ in the center of the eyeball. There are two kinds of nystagmus （UBN） and downbeat nystagmus （DBN） according to the direction of nystagmus. The diagnosis of UBN is mainly made by naked eye or electronystagmography/viewer. It is a common neuro-ophthalmologic sign in the field of vestibular medicine. In this paper, the mechanism of vertical nystagmus formation and the location of lesions were briefly introduced, in order to provide help for the diagnosis and treatment of Vertigo.

Research advances on mechanism and lesion location of vertical nystagmus / 临床耳鼻咽喉头颈外科杂志

Vertical nystagmus is a vertical nystagmus caused by structural abnormalities and/or dysfunction of the central vestibular system and observed in situ in the center of the eyeball. There are two kinds of nystagmus （UBN） and downbeat nystagmus （DBN） according to the direction of nystagmus. The diagnosis of UBN is mainly made by naked eye or electronystagmography/viewer. It is a common neuro-ophthalmologic sign in the field of vestibular medicine. In this paper, the mechanism of vertical nystagmus formation and the location of lesions were briefly introduced, in order to provide help for the diagnosis and treatment of Vertigo.

Nistagmo vertical hacia abajo / Downbeat nystagmus

RESUMEN El downbeat nystagmus o nistagmo vertical hacia abajo es el nistagmo de fijación adquirido más frecuente, que en la mayoría de los casos es causado por patología a nivel del sistema nervioso central que genera disrupción del control inhibitorio del flóculo y paraflóculo cerebeloso sobre los núcleos vestibulares. Entre sus causas se encuentran enfermedades neurodegenerativas y vasculares de cerebelo o tronco cerebral, tumores y traumas, pero cerca del 40% de los casos son idiopáticos y hasta la mitad de los pacientes presentan estudio imagenológico negativo. En este artículo presentamos dos casos que consultaron en el Servicio de Otorrinolaringología del Hospital Clínico de la Universidad de Chile.

ABSTRACT Downbeat nystagmus is the most frequent acquired fixation nystagmus and it is generally caused by central pathology disrupting the inhibitory control of the cerebellar flocculus and paraflocculus over the vestibular nuclei. Among its causes are neurodegenerative and vascular diseases of cerebellum or brainstem, tumors and trauma, but nearly 40% of the cases are idiopathic and up to half the patients have negative imaging study. In this article we present two cases that were evaluated in the Otolaryngology Department of the Clinical Hospital of the University of Chile.

Clinical and electrophysiological results of eye muscle surgery in 17 patients with downbeat nystagmus

Purpose: To test the hypothesis that eye muscle surgery in treatment of patients with acquired downbeat nystagmus results in improvement measures of visual and ocular motor function. Methods: This is a prospective, interventional case series analysis of clinical and electrophyisological data before and after eye muscle surgery in 17 patients with acquired downbeat nystagmus who did not respond to medical treatments. Outcome measures included: 1) routine demography and clinical characteristics, 2) subjective oscillopsia (SO), 3) binocular best-corrected visual acuity in the null position (BVA), 3) primary position strabismic deviation (SD), 5) anomalous head posture (AHP), 6) contrast sensitivity function (CS), and 7) nystagmus slow phase velocity (SPV). All patients were followed at least 12 months. Parametric and non-parametric statistical analysis of outcome measure data above pre- and post-treatment were perfomed using standard software on grouped data using computerized software. Results: Patients' age ranged from 5 to 85 years (average 27 years). About 59% were male. Follow up ranged from 1–10 years (average 2.0 years). Around 70% had an associated central nervous systemic diagnosis, 100% had an AHP, oscillopsia and decreased CS, 53% had other eye disease, and 59% had strabismus. There were no complications from surgery. There were signficant post-treatment improvements in mean/median group BVA, SO, SD, AHP, CS, and SPV. Conclusion: This study supports the hypothesis that eye muscle surgery as treatments for patients with acquired downbeat nystagmus can result in improvements in multiple aspects of ocular motor and visual functions.

Unique case of midbrain tuberculoma presenting as isolated inferior rectus palsy with nystagmus

Isolated brain stem tuberculoma constitutes about 5% of all intracranial tuberculomas. A case of isolated inferior rectus palsy with downbeat nystagmus due to presumed midbrain tuberculoma in an immunocompetent patient is described here. This report documents a rare entity of a combination of partial third nerve palsy with pupil involvement along with downbeat nystagmus.

Síndrome de nistagmo vertical hacia abajo: reporte de 2 casos y revisión de la literatura / Downbeat nystagmus syndrome: a report of 2 cases and literature review

El síndrome de nistagmo vertical hacia abajo (NVA) es una forma común de nistagmo de fijación adquirido que se presenta con nistagmo persistente con fase rápida en dirección descendente, mareo, oscilopsia y alteraciones de la marcha. Se considera un trastorno vestíbulo-cerebelar debido a un defecto en las células de Purkinje en el flóculo del cerebelo. Las causas reportadas con mayor frecuencia son los trastornos degenerativos cerebelares e isquemia cerebelar, sin embargo, en un gran porcentaje de los pacientes la etiología permanece incierta (forma idiopática). El NVA se puede dar en un contexto más amplio de neuropatía somatosensorial y ataxia cerebelar en el síndrome CANVAS. Las medidas terapéuticas incluyen evitar la posición supina y prona al descansar, rehabilitación vestibular y tratamiento farmacológico con aminopiridinas, entre otros. En este artículo presentamos dos casos de NVA así como la revisión de la literatura.

Downbeat nystagmus syndrome (DBN) is a frequent form of acquired fixation nystagmus, it presents with persisting nistagmus with fast phases directed downward, dizziness, oscillopsia and gait disturbances. It is considered a vestibulocerebellar disorder due to a bilateral defect of the Purkinje cells in the cerebellar flocculus. Most reported causes are degenerative disorders of the cerebellum and cerebellar ischemia, nevertheless the etiology remains unknown in a large percentage of patients (idiopathic form). DBN may present in a broader context of somatosensory neuropathy and cerebellar ataxia as in CANVAS syndrome. Therapeutic measures includes avoiding the supine and prone position when resting, vestibular rehabilitation, and pharmacologic treatment with aminopyridines, among others. In this article we present two cases of DBN and review of literature.

Clinical Characteristics of Spontaneous Downbeat Nystagmus in Koreans: Analysis of 218 Cases

BACKGROUND: Downbeat nystagmus is the most-common type of central nystagmus. However, no published study has attempted to analyze the etiology and clinical features of downbeat nystagmus in a large sample of Korean patients. METHODS: We analyzed the demographic and clinical features of spontaneous downbeat nystagmus in 218 Korean patients who had been evaluated at the Dizziness Clinic of Seoul National University Bundang Hospital from 2003 to 2014. RESULTS: All patients were aged from 15 to 92 years (mean+/-SD: 58.7+/-18.0 years), and they included 117 (53.7%) men. Underlying causes were found in 162 patients (74.3%, secondary group), while no etiology was identified in the remaining patients (idiopathic group). The age and sex distributions did not differ between the idiopathic and secondary groups. The underlying etiology included hereditary disorders (n=48, 22.0%), vascular diseases (n=46, 21.1%), and inflammatory diseases (n=19, 8.7%). Infarctions (n=34, 15.6%) and episodic ataxia (n=32, 14.7%) were the most-frequent underlying disorders. The most-common site of lesions identified by MRI was the cerebellum (68.9%), followed by the brainstem (28.6%). Among the 74 patients with lesions confirmed by MRI, 25 (33.7%) showed an isolated cerebellar involvement, while 35 (47.6%) had lesions in multiple areas. CONCLUSIONS: This study extends the clinical features of spontaneous downbeat nystagmus to Korean patients. Cerebellum is the most-common lesion site, which is consistent with the results of previous studies. The prevalence of Arnold-Chiari malformation is relatively low, which may be a distinct finding relative to those of previous studies involving other ethnic populations.

Various Nystagmus Patterns and Their Clinical Significance in Benign Paroxysmal Positional Vertigo of Anterior Semicircular Canal / 대한평형의학회지

OBJECTIVE: The purpose of this study was to identify the diverse patterns of nystagmus and analyze their clinical significance in benign paroxysmal positional vertigo (BPPV) of the anterior semicircular canal. METHODS: Fifty-three patients diagnosed with anterior canal BPPV (AC-BPPV) were analyzed retrospectively. Patients were classified according to the presence or absence of the torsional component of the nystagmus and the direction of Dix-Hallpike test which induced the nystagmus. We compared the clinical characteristics and treatment outcomes among the different patient groups. RESULTS: There were 11 patients with unilateral down beat (DB) nystagmus, 11 patients with bilateral DB nystagmus, 14 patients with ipsilateral torsional down beat (TDB) nystagmus, 7 patients with contralateral TDB nystagmus, and 7 patients with bilateral TDB nystagmus. There were no differences between the unilateral and the bilateral DB groups in terms of the duration of nystagmus or vertigo and the number of treatment sessions. In addition, the ipsilateral TDB group showed no significant clinical difference compared to the contralateral or bilateral TDB group. CONCLUSION: Various nystagmus patterns can be seen in AC-BPPV. There was no statistically significant difference in the clinical characteristics according to the different nystagmus patterns. This information may be helpful for clinicians in counseling and managing the patients with AC-BPPV.

Treatment of Downbeat Nystagmus in Arnold-Chiari Malformation using 3,4-Diaminopyridine

No abstract available.

Downbeat, Gaze-evoked and Perverted Head-shaking Nystagmus Associated with Dapsone Toxicity / 대한평형의학회지

Dapsone is an agent commonly used to treat leprosy and its most common adverse effect is a hemolytic anemia. We present a patient who showed transient downbeat, bilateral horizontal gaze-evoked nystagmus (GEN), and perverted head-shaking nystagmus after taking a large dose of dapsone. These oculomotor abnormalities are assumed to be a reversible vestibulocerebellar dysfunction caused by over-dose of dapsone.

A Case of Spinocerebellar Ataxia Type 6 Presenting Downbeat Nystagmus Alone

No abstract available.

Acquired Hepatocerebral Degeneration Presenting with Downbeat Nystagmus and Ataxia: A Case Report

Nystagmus or ataxia is a rare manifestation of acquired hepatocerebral degeneration (AHCD). A 49-year-old woman presented with downbeat nystagmus and limb and gait ataxia. She was diagnosed as primary biliary cirrhosis with a gastric varix. Brain MRI showed cerebellar vermian atrophy and characteristic T1 high-signal intensities in bilateral globus pallidi and ventral midbrain. We report a rare case of AHCD manifesting prominent cerebellar symptoms. This has not yet been reported in Korea.

Lithium-Induced Downbeat Nystagmus with Reversible Splenial Lesion

Lithium is recognized as a cause of reversible or permanent downbeat nystagmus. Many patients who were treated with lithium for psychiatric illness developed downbeat nystagmus and other neurological manifestations. Reversible splenial lesions of corpus callosum are commonly seen on diffusion-weighted imaging (DWI) in various neurological disorders including metabolic/toxic encephalopathy, encephalitis, patients with epilepsy receiving antiepileptic drugs. Herein, we report a patient with reversible downbeat nystagmus, disturbance of smooth pursuit, and gait ataxia who was treated with lithium. Also, we can observe reversible splenial lesion of corpus callosum on DWI in this patient.

Downbeat Nystagmus Associated With Brainstem Compression by Vertebral Artery

Rarely, downbeat nystagmus can occur due to compression of the lower brainstem by the ectatic vertebral artery and be resolved by microvascular decompression. We present a case of a 67-year-old man with downbeat nystagmus associated with brainstem compression by ectatic vertebral artery. He presented with oscillopsia and vertigo. When he turned his head upward, his symptoms were aggravated and a gait disturbance occurred. Magnetic resonance imaging and computed tomographic angiography demonstrated compression of the medulla oblongata by the left ectatic vertebral artery and other medical causes of downbeat nystagmus were ruled out. Retromastoid craniotomy was performed and after lifting the vertebral artery off the medulla, a trough-shaped indentation in the lower brainstem was identified. The ectatic vertebral artery was repositioned and a Teflon was inserted between the brainstem and the ectatic vertebral artery. Postoperatively, downbeat nystagmus had disappeared.

Downbeat, Positional, and Perverted Head-Shaking Nystagmus Associated with Lamotrigine Toxicity

Lamotrigine is an effective antiepileptic drug with few adverse effects. Nystagmus is one of the commonly observable signs of lamotrigine overdose, which may result from central nervous system involvement. However, the physiologic basis of lamotrigine-induced nystagmus is not fully understood. Here we report a patient who presented with lamotrigine-associated nystagmus that was probably related to cerebellar dysfunction.

Episodic Ataxia Type 2 with Downbeating Nystagmus Caused by Mutation in the CACNA1A: A Case Report

Episodic ataxia type 2 (EA 2) is a rare disorder characterized by intermittent episodes of ataxia with interictal nystagmus. The authors report a patient with EA 2, who presented with recurrent episodes of vertigo, gait ataxia and interictal downbeat nystagmus, which had developed about 16 years before. The chromosomal analysis revealed a translocation between chromosome 7 and chromosome 19 (t(7;19)). The break point in chromosome 19 was the P13 locus of the CACNA1A gene.

Mechanism of Downbeat Nystagmus While Normal Subjects HaveHead Upside-down Position in Darkness

BACKGROUND: Bohmer and Straumann have proposed that downbeat nystagmus is due to an asymmetry of the geometry of the vertical semicircular canals of the vestibular labyrinth. This hypothesis does not predict any sustained change in vertical nystagmus when subjects are placed in a head-upside-down position. METHODS: Using the magnetic search coil technique, I measured vertical eye movements in darkness in three normal human subjects while they maintained head-erect or head-upside-down positions. RESULTS: Two subjects had upbeat nystagmus and one downbeat nystagmus with their heads erect (slow-phase velocity < 1 deg/sec). All developed sustained nystagmus with quick phases directed towards their chins while in the head-upside-down position. CONCLUSIONS: These findings suggest that factors other than canal imbalance - otolithic or ocular - may also cause downbeat nystagmus.