Forms Of Nystagmus Research Articles

Historical descriptions of nystagmus and abnormal involuntary eye movements in various ancient cultures.

Original texts and expert translations from various ancient cultures covering a time span from the 2nd millennium BC to the ninth century AD were searched for historical observations of involuntary eye movements. Abnormal, spontaneous eye movements are an easily recognisable neuro-ophthalmological symptom that can be both congenital and acquired. Ocular oscillations termed 'hippos' by Hippocrates (460-370BC) and Galenos (129-216AD) are synonymous with nystagmus, a term first introduced in the eighteenth century. The original description of hippos suggests an innate onset, which retrospectively can be related to either congenital (infantile) nystagmus or continuous involuntary eye movements of the blind. Other descriptions of abnormal involuntary eye movements with different beating directions, possibly associated with vertigo, seizures or ear symptoms and their impact on patients' quality of life (e.g. oscillopsia, blurred vision) are preserved in many fragmentary ancient documents including papyrus scrolls and stone tablets from Egypt, Mesopotamia, India, China, Greece, Rome and the Middle East. Although the sparse original descriptions of the direction and type of eye movements may inspire daring medical interpretations, caution is required when attempting to assign them to distinct nystagmus forms according to our current clinical classification of ocular motor disorders.

See-saw nystagmus associated with retinitis pigmentosa.

See-saw nystagmus is an uncommon form of nystagmus, and its pathophysiology remains poorly understood since the first case reported by Maddox in 1913. 1 Furthermore, see-saw nystagmus associated with retinitis pigmentosa is very rare. To the best of our knowledge, only 2 cases of see-saw nystagmus associated with retinitis pigmentosa have been reported since 1986. 2 Here, I report a case of seesaw nystagmus associated with retinitis pigmentosa. There were no clinical cranial nerve deficits and no cerebellar signs. Magnetic resonance imaging of the brain showed no lesions of the brainstem, cerebellum or evidence of demyelination. This case shows a rare association between see-saw nystagmus and retinitis pigmentosa. It is therefore important to recognise this, and future studies are needed to provide clarity on the underlying mechanism of this clinical entity.

Nystagmus in Children - a Survey

Nystagmus describes an involuntary, periodic movement of one or both eyes. About 1/600 children and adolescents have nystagmus, most of them idiopathic infantile nystagmus (IIN), also called "congenital nystagmus", which can be caused by mutations in the FRMD7 gene. Other frequent forms of nystagmus are latent nystagmus, which is usually associated with infantile strabismus, and nystagmus associated with albinism. Sometimes difficult to distinguish in young infants is a sensory nystagmus, where a defect in the visual system reduces vision and causes nystagmus. Causes include retinal dystrophies, congenital stationary night blindness and structural ocular defects including optic nerve hypoplasia or dense bilateral congenital cataracts. Unilateral nystagmus can be the sign of an anterior visual pathway lesion. Seesaw nystagmus may be associated with suprasellar and mesodiencephalic lesions and - rarely - with retinal dystrophies.The ophthalmology plays a key role in identifying the form of nystagmus. Children with new onset nystagmus, with spasmus nutans, with vertical or unilateral nystagmus and those with seesaw nystagmus require neurologic evaluation including imaging of the brain.The treatment of nystagmus depends on the underlying cause. Even minor refractive errors should be corrected, contact lenses offer advantages over glasses.Gabapentin and memantine, possibly also carbonic anhydrase inhibitors, are effective in treating IIN, nystagmus in albinism and sensory nystagmus. Nevertheless, pharmacologic treatment of nystagmus is rarely used in children; the reasons are the limited effects on vision, the need for lifelong therapy, and potential side effects. Eye muscle surgery (Anderson procedure, Kestenbaum procedure) can correct a nystagmus-related anomalous head posture. The concept of "artifical divergence" of Cüppers may help to decrease nystagmus intensity in patients whose nystagmus dampens with convergence. The four-muscle-tenotomy, which involves disinsertion and reinsertion of the horizontal muscles at the original insertion of both eyes, has a proven but limited positive effect on visual acuity.

FRMD7 Gene Alterations in a Pakistani Family Associated with Congenital Idiopathic Nystagmus.

Congenital idiopathic nystagmus (CIN) is an oculomotor disorder characterized by repetitive and rapid involuntary movement of the eye that usually develops in the first six months after birth. Unlike other forms of nystagmus, CIN is widely associated with mutations in the FRMD7 gene. This study involves the molecular genetic analysis of a consanguineous Pakistani family with individuals suffering from CIN to undermine any potential pathogenic mutations. Blood samples were taken from affected and normal individuals of the family. Genomic DNA was extracted using an in-organic method. Whole Exome Sequencing (WES) and analysis were performed to find any mutations in the causative gene. To validate the existence and co-segregation of the FRMD7 gene variant found using WES, sanger sequencing was also carried out using primers that targeted all of the FRMD7 coding exons. Additionally, the pathogenicity of the identified variant was assessed using different bioinformatic tools. The WES results identified a novel nonsense mutation in the FRMD7 (c.443T>A; p. Leu148 *) gene in affected individuals from the Pakistani family, with CIN resulting in a premature termination codon, further resulting in the formation of a destabilized protein structure that was incomplete. Co-segregation analysis revealed that affected males are hemizygous for the mutated allele c.443T>A; p. Leu148 * and the affected mother is heterozygous. Overall, such molecular genetic studies expand our current knowledge of the mutations associated with the FRMD7 gene in Pakistani families with CIN and significantly enhance our understanding of the molecular mechanisms involved in genetic disorders.

Conserved subcortical processing in visuo-vestibular gaze control

Gaze stabilization compensates for movements of the head or external environment to minimize image blurring. Multisensory information stabilizes the scene on the retina via the vestibulo-ocular (VOR) and optokinetic (OKR) reflexes. While the organization of neuronal circuits underlying VOR is well-described across vertebrates, less is known about the contribution and evolution of the OKR and the basic structures allowing visuo-vestibular integration. To analyze these neuronal pathways underlying visuo-vestibular integration, we developed a setup using a lamprey eye-brain-labyrinth preparation, which allowed coordinating electrophysiological recordings, vestibular stimulation with a moving platform, and visual stimulation via screens. Lampreys exhibit robust visuo-vestibular integration, with optokinetic information processed in the pretectum that can be downregulated from tectum. Visual and vestibular inputs are integrated at several subcortical levels. Additionally, saccades are present in the form of nystagmus. Thus, all basic components of the visuo-vestibular control of gaze were present already at the dawn of vertebrate evolution.

Dissociated Vertical-Torsional Nystagmus in Vestibular Nucleus Lesion

Dissociated vertical-torsional nystagmus is a unique form of nystagmus characterized by conjugate torsional but disparate vertical components. It has been mainly reported in internuclear ophthalmoplegia or medial medullary lesion involving the medial longitudinal fasciculus (MLF). The patterns of the nystagmus may be explained by a disruption of vestibulo-ocular reflex pathways from vertical semicircular canal or utriculo-ocular reflex within the MLF, but it is debatable. We described a dissociated upbeat-torsional nystagmus in a patient with vestibular nucleus infarction without involvement of MLF.

Characteristics of nystagmus and its therapeutic effect in the reduction of posterior semicircular canal benign paroxysmal positional vertigo

Objective:By observing the nystagmus forms at different positions during Epley reduction in patients with posterior semicircular canal benign parochial positional vertigo（PC-BPPV）, to compare the effects of the first reduction, and to further summarize the possible causes of reduction failure and the prognosis of patients with different nystagmus forms. Methods:A retrospective analysis of 191 PC-BPPV patients diagnosed with PC-BPPV showed that 95 cases had positive nystagmus during the reduction process（group A）, 69 cases had no nystagmus （group B）, and 27 cases had reverse nystagmus （group C）. All the patients were diagnosed by G-Force BPPV and were treated through simulative Epley CRP. The form of nystagmus and the effect of the first reduction were compared. Results:The first reduction effect of group A was better than that of group C（P<0.05）. The reduction effect of group B was better than that of group C（P<0.05）. There was no significant difference in the reduction effect between group A and group B（P>0.05）. Conclusion:The form of nystagmus in the reduction process of PC-BPPV has a certain guiding significance for the evaluation of the first reduction effect and the successful reduction. The reverse nystagmus during the reduction process indicates a poor reduction effect.

Analysis of Dix-Hallpike maneuver induced nystagmus based on virtual simulation

Background How to interpret the various forms of nystagmus induced by the Dix-Hallpike maneuver has been the hotspot and difficulty of research. Objectives Analysis of the types of nystagmus induced by Dix-Hallpike maneuver, and establish a diagnosis strategy based on dynamic nystagmus observation. Materials and methods We observed the otolithic movements at different locations during the Dix-Hallpike maneuver through physical virtual simulation experiments and inferred the nystagmus performance, so as to establish the nystagmus interpretation rules for the repeated Dix-Hallpike maneuver. Results There are six types of nystagmus induced by the Dix-Hallpike maneuver. Nystagmus induced by the unilateral Dix-Hallpike maneuver does not accurately locate the otolith. The typical nystagmus that is consistent before and after the repetition of the Dix-Hallpike maneuver is the outward and upbeat nystagmus, considering the ipsilateral posterior semicircular canal BPPV. Conclusion The atypical nystagmus often turns negative when the Dix-Hallpike maneuver is repeated. If the repeat test is positive and consistent with the results of the first diagnostic test, the otolith can be accurately located.

Ocular movement and nystagmus: basics and clinical diagnosis

Eye movements are one of the most complex motor functions of the central nervous system (CNS). Eye movement disorders including nystagmus occur in diseases of the CNS and the vestibular system. Asystematic clinical examination often allows atopodiagnostic classification of the lesion. The basics of eye movements, the role of the cerebellum, the clinical examination of the oculomotor system, and the most important forms of nystagmus and their diagnostic implications are described. A literature analysis assessing eye movements, cerebellar control of eye movements, clinical examination of eye movement, and nystagmus was performed. In disorders of eye movement, diseases of the oculomotor cranial nerves and the central nervous structures are to be distinguished from diseases of the orbit, eye muscles, and motor end plates. The former result in cranial nerve-related paralysis of extraocular muscles, disturbances of saccadic and smooth pursuit eye movements, vertical or horizontal gaze palsy, internuclear ophthalmoplegia, or impaired gaze holding. Nystagmus in combination with other disturbances of ocular movement is highly related to alesion within the CNS. Intense nystagmus with arotatory component that decreases during fixation usually has aperipheral vestibular cause. Clinical examination of eye movements and nystagmus enables the diagnosis of typical eye movement disorders with astrong relation to distinct lesions of the CNS or the peripheral vestibular pathway.

Wernicke encephalopathy—a rare complication of hyperemesis gravidarum

We report a rare case of Wernicke encephalopathy (WE) in a 35-year-old woman with hyperemesis gravidarum (HG). Initially, the disease manifested as passivity, a loss of interest, sleeping too much, apathy and disorientation. The correct diagnosis was established after the detection of typical pathological findings of WE in the thalamus by magnetic resonance imaging (MRI), which was indicated for the appearance of eye symptomatology in the form of nystagmus. Subsequent treatment with thiamine led to rapid improvement in the patient's clinical status and a favorable course of pregnancy.

Surgical Treatment of a Patient with See-Saw Nystagmus (SSN): Case Report

Background: Acquired See-saw Nystagmus (SSN) is a rare form of nystagmus characterized by elevation and intorsion of one eye with synchronous depression and intorsion of the contralateral eye in the first half cycle, followed by a reversal in the direction of the movements during the next half cycle. We herein report a case of a 47-year-old woman with a 3-year history of constant diplopia as a consequence of multiple neurosurgical interventions due to hemorrhage from a cavernous angioma located in the subthalamic region. She also had a history of major depressive disorder and ulcerative colitis. The patient underwent a surgical intervention with a 5 mm bilateral recession of the superior and inferior rectus muscles. Five years after surgery, the patient reported less recurrent and prominent episodes of transient horizontal deviation with horizontal diplopia, with a prevalence of well-being and comfort.

Arnold-Chiari Type 1 Malformation Mimicking Benign Paroxysmal Positional Vertigo

Arnold-Chiari malformation type 1 is a congenital disease characterized by herniation of the cerebellar tonsils through the foramen magnum. Most common clinical symptom is pain, including occipital headache and neck pain, upper limb pain exacerbated by physical activity or valsalva maneuvers. Various otoneurological manifestations also occur in patients with the disease, which has usually associated with dizziness, vomiting, dysphagia, poor hand coordination, unsteady gait, numbness. Patients with Arnold-Chiari malformation may develop vertigo after spending some time with their head inclined on their trunk. Positional and down-beating nystagmus are common forms of nystagmus in them. We experienced a 12-year-old female who presented complaining of vertigo related to changes in head position which was initially misdiagnosed as a benign paroxysmal positional vertigo. Keywords: Arnold-Chiari malformation; Dizziness; Benign paroxysmal positional vertigo; Headache 중심 단어: 아놀드-키아리 기형, 어지럼증, 양성돌발성두위현훈, 두통

Central positional nystagmus: Characteristics and model-based explanations.

The central vestibular system operates to precisely estimate the rotational velocity and gravity orientation using the inherently ambiguous information from peripheral vestibular system. Therefore, any lesions disrupting this function can generate positional nystagmus. Central positional nystagmus (CPN) can be classified into the paroxysmal (transient) and persistent forms. The paroxysmal CPN has the features suggesting a semicircular canal origin regarding the latency, duration, and direction of nystagmus. Patients with paroxysmal CPN commonly show several different types of nystagmus classified according to the provoking positioning. The persistent form of CPN mostly appears as downbeat nystagmus while prone or supine, or apogeotropic or geotropic horizontal nystagmus when the head is turned to either side while supine. CPN may be ascribed to erroneous neural processing within the velocity-storage circuit that functions in estimating angular head velocity, gravity direction, and inertia. Paroxysmal CPN appears to be post-rotatory rebound nystagmus due to lesions involving the cerebellar nodulus and uvula. In contrast, persistent CPN may arise from erroneous gravity estimation. The overlap of lesion location responsible for both paroxysmal and persistent CPN may account for the frequent coexistence of both forms of nystagmus in a single patient.

An Overview of Central Vertigo Disorders.

Head motion recorded by the vestibular labyrinths is conveyed to specific brainstem and cerebellar structures that relay velocity information to eye muscles to stabilize vision, and to the axial and limb muscles necessary to stabilize balance. Neural networks enhance and extend the primary vestibular signal, and create adaptation to movement when appropriate. Pathological lesions to one or more of these structures may cause central vertigo and imbalance, and may be localized by specific forms of nystagmus and other abnormal neurological signs. Vertigo treatment may be directed to the underlying disease, or it may be lessened by one of several centrally acting pharmacologic agents that have recently shown promise.

The clinical characteristics of the evoked nystagmus in the non-affected side during Dix-Hallpike test in the unilateral posterior semicircular canal benign paroxysmal positional vertigo

Objective: To investigate the clinical characteristics of the evoked nystagmus in the non-affected side during Dix-Hallpike test(D-H test)in unilateral posterior semicircular canal benign paroxysmal positional vertigo(PC-BPPV). Method: Two hundred and thirty-six patients were diagnosed with unilateral PC-BPPV in the Tinnitus and Dizziness clinic.Among them,14 patients exhibited positive nystagmus when the non-affected side was stimulated by D-H test. The clinical data from this subgroup of patients were retrospectively analyzed. Result: The upbeat and torsional nystagmus of 14 patients were all evoked by D-H test in the affected side. 11 cases were right PC-BPPV and 3 cases were left PC-BPPV. Among these 14 patients, 5 patients exhibited the upbeat and torsional nystagmus during D-H test in the non-affected side, which was in the same direction as that evoked in the affected side. Among them, 4 cases were right PC-BPPV and 1 case was left PC-BPPV. However, the downbeat nystagmus of the remaining 9 patients were evoked by D-H test in the non-affected side, in which 7 cases were right PC-BPPV and 2 cases were left PC-BPPV.The nystagmus and vertigo of all patients completely disappeared after performing the Epley or Semont repositioning maneuvers on the affected side. Conclusion: The bilateral positive nystagmus of unilateral PC-BPPV can be evoked by D-H test. The form of nystagmus on the non-affected side is related with the initial position of otoconia in affected semicircular canal and the moving direction of otoconia during the positional test. It is effective to perform Epley or Semont repositioning maneuvers on the affected side. Meanwhile, both the effect of maneuvers and the type of nystagmus evoked by D-H test can verify which side is affected.

Long-Term Follow-up of Spasmus Nutans

ABSTRACTPurpose: Spasmus nutans is an acquired form of nystagmus that is classically associated with torticollis and titubations of the head, often presenting in the first year of life and spontaneously resolving within the next 2 years. The purpose of our study was to record and characterize the long-term prognosis of children diagnosed with spasmus nutans.Methods: All patients under the age of 21 years with a diagnosis of spasmus nutans were included. Parameters of age, nystagmus symmetry and quality, presence of titubations, torticollis, and strabismus, and findings on CT or MRI were recorded.Results: Our 22 patients had an average age of onset of 9.8 and a follow-up of 62.6 months. Nystagmus was unilateral in 5 children, asymmetric in 5, symmetric in 10, and inapparent in 2. Titubations were identified in 10 and torticollis in 7. Nystagmus persisted in 16 of 20 children, titubations in 3, and torticollis in 6. Neuroimaging, performed on 17 of the 22 children, was negative for any space-occupying lesions.Conclusion: In conclusion, we are reluctant to assure parents of children who have even the most typical spasmus nutans that their child will be normal after a predictable interval. Instead, we advise them that many children do well, assuming normal imaging, but that nystagmus, torticollis, and even titubations may persist. Follow-up, especially for strabismus and amblyopia, should be continued throughout childhood.

Clinical significance of spontaneous nystagmus in pediatric patients

ObjectiveTo analyze spontaneous nystagmus recorded in pediatric patients and determine its diagnostic value. Materials and methodsRetrospective review of 86 patients (mean age = 13.9 ± 4.7 years) with definitive spontaneous nystagmus recorded by videonystagmography (VNG). Spontaneous nystagmus was categorized and analyzed based on its characteristics. Correlations between spontaneous nystagmus and established clinical diagnoses were explored. ResultsAmong the patients seen in a period of three years at our pediatric vestibular clinic, 15.4% (86 out of 560) were found to have spontaneous nystagmus and half of them had horizontal nystagmus with a fixed-direction. The majority of cases with spontaneous nystagmus (77%, 66/86) were present without fixation only, while the presence of spontaneous nystagmus with and without fixation was found in 16 patients (19%). Most patients with spontaneous nystagmus without fixation only (68%) were diagnosed with a peripheral vestibular disorder (e.g., vestibular neuritis) or vestibular migraine. In contrast, vertical nystagmus was found in 15 patients, most of whom had central vestibular disorders. Other rare forms of nystagmus or abnormal eye movements, such as pendular nystagmus, ocular oscillation or flutter were recorded in only four patients. ConclusionsSpontaneous nystagmus in children and young adults with possible vestibular impairments may vary in clinical presentation. Identification of its characteristics may help to make an accurate clinical diagnosis. While spontaneous nystagmus associated with peripheral vestibular disorders can be readily recognized, spontaneous nystagmus in pediatric patients with vestibular migraine appears to be more complex and variable in form.

Nystagmus.

The clinical and laboratory assessment of nystagmus in patients with neurologic disorders can provide crucial elements for a state-of-the-art differential diagnosis. An increasing number of publications in the fields of neuro-otology and neuro-ophthalmology have nystagmus in the center of interest, which makes frequent updates on the diagnostic and therapeutic relevance of these contributions indispensable. This review covers important clinical studies and studies in basic research relevant for the neurologist published from January 2016 to August 2017. Current themes include vestibular nystagmus, positional nystagmus, optokinetic nystagmus and after-nystagmus, vibration-induced nystagmus, head-shaking nystagmus, postrotatory nystagmus, caloric nystagmus, nystagmus in cerebellar disorders, differential diagnosis of nystagmus and treatment approaches (whereas infantile nystagmus syndrome is not addressed in this review). These studies address mechanisms/pathomechanisms, differential diagnoses and treatment of different forms of nystagmus. In clinical practice, a structured description of nystagmus including its three-dimensional beating direction, trigger factors and duration is of major importance. The differential diagnosis of downbeat nystagmus is broad and includes acute intoxications, neurodegenerative disorders and cerebrovascular causes amongst others. In patients with positional nystagmus, the distinction between frequent benign peripheral and rare but dangerous central causes is imperative.

Infantile nystagmus: an optometrist&amp;rsquo;s perspective

Infantile nystagmus (IN), previously known as congenital nystagmus, is an involuntary to-and-fro movement of the eyes that persists throughout life. IN is one of three types of early-onset nystagmus that begin in infancy, alongside fusion maldevelopment nystagmus syndrome and spasmus nutans syndrome. Optometrists may also encounter patients with acquired nystagmus. The features of IN overlap largely with those of fusion maldevelopment nystagmus syndrome, spasmus nutans syndrome, and acquired nystagmus, yet the management for each subtype is different. Therefore, the optometrist’s role is to accurately discern IN from other forms of nystagmus and to manage accordingly. As IN is a lifelong condition, its presence not only affects the visual function of the individual but also their quality of life, both socially and psychologically. In this report, we focus on the approaches that involve optometrists in the investigation and management of patients with IN. Management includes the prescription of optical treatments, low-vision rehabilitation, and other interventions such as encouraging the use of the null zone and referral to support groups. Other treatments available via ophthalmologists are also briefly discussed in the article.

Incidence and Types of Pediatric Nystagmus

To report the incidence, prevalent subtypes, and clinical characteristics of pediatric nystagmus diagnosed over a 30-year period. Retrospective, population-based study. Using the Rochester Epidemiology Project, we reviewed the medical records of all children (<19 years) diagnosed as residents in Olmsted County, Minnesota, with any form of nystagmus from January 1, 1976, through December 31, 2005. Seventy-one children were diagnosed during the 30-year period, yielding an annual incidence of 6.72 per 100,000 younger than 19 years (95% confidence interval [CI], 5.15-8.28) Infantile nystagmus, onset by 6months, comprised 62 (87.3%) of the study patients, corresponding to a birth prevalence of 1 in 821. The median age at diagnosis for the cohort was 12.7months (range, 0days to 18.6 years) and 42 subjects (59.2%) were male. The main types of nystagmus, in declining order, were nystagmus associated with retinal/optic nerve disease in 23 (32.4%), idiopathic or congenital motor nystagmus in 22 (31.0%), manifest latent nystagmus or latent nystagmus in 17 (24.0%), and 2 (2.8%) each associated with Chiari malformation, medication use, tumor of the central nervous system, and no diagnosis. Developmental delay was diagnosed in 31 (43.6%), strabismus in 25 (35.2%), and amblyopia in 10 (14.1%). Eighty percent had 20/40 (or equivalent) or better vision at presentation in at least 1 eye. This study provides population-based data on incidence and clinical characteristics of childhood nystagmus in North America. Idiopathic and nystagmus associated with retinal/optic nerve disease were the most common presentations, with most patients having good vision. Developmental delay, strabismus, and amblyopia were common in this cohort.