Changes In Nystagmus Research Articles

Evolution of Vestibular Findings During and Between the Attacks of Meniere Disease: Update.

The diagnosis of Meniere disease (MD) has based on characteristics of vertigo and findings of audiologic evaluation. This review focuses on the recent findings of the evolution of vestibular function and their underlying physiology during and between the attacks of MD and thus aims to help identify this common disorder with many faces according to the phase. During the attacks, the direction of spontaneous nystagmus changes over time, beating initially toward the affected ear (irritative nystagmus), then toward the healthy ear (paretic nystagmus), and finally back toward the affected ear again (recovery nystagmus). Apart from these direction changes, atypical forms of spontaneous nystagmus, such as downbeat, discordant horizontal-torsional, and aperiodic alternating nystagmus, can be observed. Head impulse tests (HITs) are mostly normal during the irritative/recovery phases, but positive in more than half of patients during the paretic phase. By contrast, caloric tests are usually abnormal irrespective of the phases, although paradoxical caloric hyper-responsiveness can be observed in 18% of patients during the irritative/recovery phases. Thus, dissociation in the findings of caloric tests-HITs can be observed during and between the attacks. Horizontal head shaking tends to augment spontaneous nystagmus during each phase, while skull vibration mostly induces nystagmus beating toward the healthy ear irrespective of the phases. During the attacks, ocular vestibular-evoked myogenic potentials (VEMPs) may be enhanced, whereas cervical VEMPs are usually decreased during stimulation of the involved ear. Recognizing these evolutions of vestibular findings during and between the attacks of MD would provide insights into its pathophysiology and aid in treatments and diagnosis.

Analysis of etiology and clinical features of spontaneous downbeat nystagmus: a retrospective study.

To investigate the topical diagnosis, possible etiology and mechanism of spontaneous downbeat nystagmus (sDBN) patients with dizziness/vertigo. The clinical features of dizziness/vertigo patients accompanied with DBN were retrospectively reviewed in the Vertigo Center of our hospital from January 2018 to March 2021. The clinical features of dizziness/vertigo patients accompanied with DBN were reviewed. Comprehensive VNG, bithermal caloric testing, video-head-impulse test (vHIT), vestibular-evoked myogenic potentials (VEMP), head magnetic resonance imaging (MRI), three-dimensional fluid-attenuated incersion recovery magnetic resonance imaging (3D-FLAIR MRI) in the inner ear, serum immunology and other examinations were to determine the lesion site, and analyze its possible etiology and mechanism. A total of 54 patients were included. Among them, 70.4% (n = 38) of DBN patients were diagnosed with episodic vestibular syndrome (EVS), 22.2% (n = 12) with chronic vestibular syndrome (CVS), and 7.4% (n = 4) with acute vestibular syndrome (AVS). Among all the patients, 51.9% of DBN patients had clear etiology, with central lesions of 29.6% and peripheral diseases of 22.2%. The most common diseases in DBN patients were cerebellar lesions (13.0%, n = 7) and vestibular migraine (13.0%, n = 7), followed by benign positional paroxysmal vertigo (7.4%, n = 4) and drug-related dizziness/vertigo (5.6%, n = 3). The other 48.1% of the patients had unknown etiology. 53.8% (14/26) of patients with idiopathic DBN had decreased semicircular canal function, with 42.9% (6/14) decreased posterior semicircular canal function. The posterior semicircular canal gain in DBN patients decreased compared to the anterior semicircular canal in the same conjugate plane. Patients with peripheral DBN were more prone to horizontal/torsional nystagmus during positional testing. In our study, DBN patients have a relative decrease in posterior semicircular canal gain, which is possibly a particular result found in a subset of downbeat nystagmus patients. The changes in nystagmus during positional testing may be helpful in distinguishing between peripheral and central causes.

Clinical evaluation of acute phase nystagmus associated with cerebellar lesions

To determine the characteristics of acute phase nystagmus in patients with cerebellar lesions, and to identify a useful indicator for differentiating central lesions from peripheral lesions. Acute phase nystagmus and the appearance of neurological symptoms were retrospectively investigated in 11 patients with cerebellar stroke. At the initial visit, there were no patients with vertical nystagmus, direction-changing gaze evoked nystagmus or pure rotatory nystagmus. There were four cases with no nystagmus and seven cases with horizontal nystagmus at the initial visit. There were no neurological symptoms, except for vertigo and hearing loss, in any cases at the initial visit. The direction and type of nystagmus changed with time, and neurological symptoms other than vertigo appeared subsequently to admission. It is important to observe the changes in nystagmus and other neurological findings for the differential diagnosis of central lesions.

Modern technologies of the diagnostics of vestibular dysfunction in neurological practice

Assessment of vestibular dysfunction is a fine criterion of the functional state of brain systems responsible for spatial comfort. Long-term studies of oculomotor reactions in neurological and otological practice clearly showed nystagmus as an important sign of the CNS disorder. Being an objective, temporal clinical phenomenon, nystagmus is seen visually, it can be easily registered and assessed quantitatively. Most difficult is to detect latent vestibular dysfunction, i.e. cases when nystagmus cannot be observed on routine neurological examination. The use of special equipment allows to evaluate quantitative and qualitative parameters of nystagmus, especially those not seen visually (dysrhythmia) or hardly registered (amplitude irregularity, nystagmus changes after different functional tests, etc.). Potential and clinical evaluation of modern technologies of the diagnostics of vestibular dysfunction are presented on a number of clinical cases.

Upbeat nystagmus changes to downbeat nystagmus with upward gaze in a patient with Wernicke's encephalopathy

We describe a patient with Wernicke's encephalopathy who showed spontaneous upbeat nystagmus with decelerating slow phases that changed to downbeat nystagmus during upward gaze and increased during downward gaze. He also showed horizontal gaze-evoked nystagmus and impaired upward smooth pursuit. Magnetic resonance imaging demonstrated symmetric lesions involving the bilateral medial thalami, periaqueductal gray matters and inferior cerebellar peduncles. In this patient, the decelerating slow phases and disobedience to Alexander's law of upbeat nystagmus suggest both deficient (leaky) and unstable neural integrators subserving vertical eye motion. Dysfunction of the interstitial nucleus of Cajal or its descending pathway to the vestibulocerebellum via the paramedian tract cell groups may be responsible for the upbeat nystagmus and its modulation by gazes in our patient with Wernicke's encephalopathy.

A study of acute phase nystagmus in 15 patients with cerebrovascular lesions

It is known that gaze-evoked nystagmus, upbeat nystagmus, down beat nystagmus and pure rotatory nystagmus are associated with central lesions, but these types of nystagmus do not always appear in the acute phase of vertigo in patients with a central disorder. In this study, we retrospectively investigated acute phase nystagmus in 15 patients with cerebrovascular lesions. All patients were attending an ENT clinic because of a lack of marked findings concerning neurological dysfunction except vertigo, but finally they were diagnosed as having vascular lesions in the posterior fossa, 3 patients with medulla infarction, 3 patients with pons infarction, 8 patients with cerebellar infarction and 1 patient with cerebellar hemorrhage.At the initial visit to the ENT clinic, spontaneous nystagmus was observed in all patients with a brainstem infarction and in 3 out of 9 patients with cerebellar lesions. Their nystagmus was the horizontal type or the horizontal type with a torsional component. All patients initially were suspected of having peripheral lesions at the initial visit or on admission, but the direction and the type of nystagmus changed periodically and neurological symptoms except vertigo appeared subsequently to admission. Diagnosis of central lesion was made with MRI. It is difficult to differentiate central lesions from peripheral lesions on the grounds of the direction and type of nystagmus, but it is important to observe the changes in nystagmus and other neurological findings for the differential diagnosis of central lesions.

Implication of vibration induced nystagmus in Meniere's disease

Conclusion. The incidence of ipsilesional beating vibration induced nystagmus (VIN) is significantly higher in Meniere's disease (MD) with lower canal paresis (CP) group on caloric test and the intensity of VIN shows significant positive correlation with CP. Considering previous reports showing predominant loss of type II hair cells in MD and discrepancy of the results between caloric test and head thrust test in MD patients, VIN may provide valuable information regarding the functional reservoir of vestibular type II hair cells in MD. Objectives. Clinical presentation of MD is dynamic and nystagmus changes phase to phase, which is attributed to the recovery process in addition to central compensation after active vertigo attack of MD. VIN has been shown to reflect the side difference of peripheral vestibular excitability and is well correlated with the severity of caloric weakness in vestibular neuritis. Aim of this study was to compare the intensity and the direction of VIN with CP in unilateral MD. Materials and methods. 52 patients with unilateral definite MD on AAO-HNS guideline (1995) were included. Auditory and vestibular function tests including caloric test, post-head shaking nystagmus (HSN) and VIN were evaluated during symptom free period and cases with spontaneous nystagmus were excluded. Vibratory stimuli (100 Hz) were applied to either mastoid alternatively. Eye movement was recorded using video nystagmography system. The horizontal component of VIN was compared with HSN and caloric test. Results. 37 patients (71%) showed VIN. VIN to ipsilesional side was in 10 and to contralesional side in 27. In patients with CP over 43% (N =23), 2 beated to ipsilesional side, 17 to contralesional side and 4 showed no VIN. In patients with CP of less than 43% (N =29), 8 beated to ipsilesional side, 10 to contralesional side and 11 showed no VIN (p<0.05). 33 patients (63%) showed HSN and 24 patients of them (72%) showed contralesional nystagmus. The intensity of VIN shows significant positive correlation with the degree of CP on caloric test (Spearman's rho =0.340, p<0.05).

Habituation of Horizontal Nystagmus of the Eyes in Pigeons in Conditions of Alternating Central and Eccentric Rotations

Intact pigeons (n=19) were rotated in the dark in the horizontal plane in different orientations relative to the axis of rotation. In central (evoking habituation) rotations, the animal's head was located on the axis of rotation; in eccentric rotations, the animal's head was 0.6 m from the axis of rotation. Pigeons were subjected to series of alternating central and eccentric rotations; rotation directions were also alternated. Series consisted of 2-5 rotation using a trapezoidal program. Each stimulus evoking habituation was used no more than 14 times during the experiment. Eccentric rotations were found not to prevent the gradual decrease in the peak rates of the slow components of primary nystagmus occurring on the transition from one series of central rotations to another in 17 individuals (group 1); these were increased in two individuals (group 2). Group 1 showed direct relationships between changes in this measure of primary nystagmus, changes in the duration of nystagmus, and changes in the peak rates of secondary nystagmus. Modifications of nystagmus within series varied. When two identical stimuli did not follow immediately one after the other, the second stimulus induced the same changes in nystagmus as observed in the individual in the first and next series of central rotations. If two identical stimuli followed one immediately after the other, the second stimulus in the pair often induced increases in the peak rates of primary and secondary nystagmus, along with increases in the time taken to reach the peak rate of primary nystagmus. These changes were non-random at a probability of >95%.

Pathophysiology and diagnosis of congenital periodic alternating nystagmus

Purpose Not many cases of congenital periodic alternating nystagmus have been reported in Japan. We investigated the pathophysiology and diagnosis of congenital periodic alternating nystagmus, noting the age when this disease began, which had not been reported previously. Subjects Ninety-one patients with congenital nystagmus who were seen in our department in the Teikyo University School of Medicine between July 1994 and January 2002 were studied. Results Eighteen patients (19.8%) among the 91 congenital nystagmus patients were diagnosed with congenital periodic alternating nystagmus. A manifestation of the periodic face turning was seen between the ages of 3 and 9 years. Visual acuity over 0.6 with correction was obtained in all patients. Almost all the patients had an asymmetric cycle of null point shifting, and the face turning was seen at one side for a long time. Conclusion When we see congenital nystagmus patients whose face turning alters periodically with fairly good vision over the age of three, we must check out the direction of jerk nystagmus changes at the same gazing point using electronystagmography or video cassette recording to detect the possibility of congenital periodic alternating nystagmus.

Fragmentary control of vestibuloocular responses.

Intact pigeons (n = 64) were rotated in the dark in the horizontal plane at different orientations relative to the axis of rotation. The overall patterns of changes in nystagmus of the eyes arising as a result of displacement of the otolith membranes in several directions were analyzed. In ten pigeons, all changes in nystagmus (type 1 general patterns) could be explained in terms of the dynamics of peripheral neuron activity and non-specific (identical for all combinations of interacting inputs) central influences. In the remaining pigeons, part of the change in nystagmus (type 2 general patterns) was associated with central influences which were not identical for different combinations of interacting inputs. Repeated unusual combinations of vestibular stimuli and subsequent treatment with Nembutal transformed type 2 general patterns into type 1 general patterns. These data provide evidence for the fragmentary control of eye movements, whereby there is selective (fragmentary) modification of only some (individually specific) combinations of canal and otolith signals out of the whole set of vestibuloocular responses arising in response to stimulation of paired vestibular inputs; modification is mediated by changes in the sign of otolith influences on the canal components of these responses.

Relationships among visual acuity demands, convergence, and nystagmus in patients with manifest/latent nystagmus

Background: We investigated the role convergence plays in nystagmus dampening, in particular, relationships among visual acuity demands, convergence, and nystagmus. Previously we showed that subjects with idiopathic infantile nystagmus exhibit a range of responses to acuity targets, one of which is nystagmus blockage syndrome. We report herein eye movement responses to acuity targets of patients with manifest/latent nystagmus. Methods: Fourteen patients, 11 with latent or manifest latent nystagmus and 3 with combined manifest latent with infantile nystagmus, were asked to indicate the direction of the gap in Landolt C optotypes while their eye movements were recorded. Results: The tested patients exhibited various responses to acuity demands: (1) dampening of nystagmus with convergence (i.e., nystagmus blockage syndrome) ( 5 14 patients), (2) changes in vergence without nystagmus dampening (2 patients), (3) decrease of nystagmus without convergence (2 patients), and (4) little change in nystagmus or vergence (5 patients). In nystagmus blockage syndrome the amount of convergence increased with acuity demands in two of five patients and the convergence duration in four of five patients; nystagmus dampening increased with acuity demands in one of five patients and the blockage duration in four of five patients. Conclusions: Many, but not all, patients with manifest/latent nystagmus, similar to those with infantile nystagmus, used convergence to dampen their nystagmus. The convergence response tended to increase with acuity demands, but the amount of dampening was idiosyncratic and not predictably related to the measured convergence across patients.

Congenital Periodic Alternating Nystagmus: Diagnosis and Management

Purpose: The purpose of the study is to investigate diagnostic criteria and treatment methods for patients with congenital periodic alternating nystagmus (PAN).Methods: A retrospective analysis was performed of clinical findings and serial eye movement recordings of patients with congenital PAN. Eighteen patients observed from 1983 through 1996 and diagnosed with congenital PAN are included. Five of these have ocular or oculocutaneous albinism. Nine of the 18 patients were treated. Three had Kestenbaum operations before referral to the authors, one was treated with baclofen, and five had large recessions of the four horizontal recti.The studied parameters included visual acuity (VA) and abnormal head posture (AHP); temporal aspects of PAN cycle, nystagmus waveforms, frequency, amplitude, and velocity; as well as mean foveation fraction, a mean percentage of the nystagmus cycle spent at retinal slip velocities less than 10° per second.Results: The authors diagnosed PAN in 9% of patients with congenital nystagmus, although most had not been diagnosed with PAN before referral, despite changing nystagmus. Sixteen patients had AHP, typically shifting. The PAN cycle was of variable duration, often with asymmetric right- and left-beating components. Although horizontal jerk nystagmus with accelerating slow phase was predominant, other waveforms were encountered in the active phase of PAN. In the quiet phase (close to null zone), similar, but less intense, oscillations than those in the active phase were characteristic. Half of the patients showed a combination of waveforms in both phases. Baclofen treatment was unsuccessful. Patients who had Kestenbaum procedures remained with AHP in the original or opposite direction, without change in nystagmus or VA. Large recessions of four horizontal recti proved uncomplicated. This treatment improved, at least for several years, AHP and VA and caused favorable changes in nystagmus parameters in all patients. Mean foveation fractions increased significantly after surgery.Conclusions: Congenital PAN often is underdiagnosed. Differing waveforms may indicate PAN. Evaluation of nystagmus, especially before surgery, for at least 3 minutes, preferably with eye movement recordings, is necessary to diagnose PAN and perhaps prevent Kestenbaum procedures, which seem inappropriate. Large horizontal recti recessions seem to provide safe and promising treatment.

Optokinetic Oculomotor Responses and the Perception of Depth from Motion Parallax Cues

In a series of experiments we studied the relationships between the characteristics of optokinetic oculomotor responses triggered spontaneously by large-field visual motion and the perception of depth from motion parallax cues. Random-dot dynamic displays were projected at 60 Hz frame rate. Oculomotor behaviour was monitored with an infrared device. Subjects were asked to identify the spatial structure specified by optical motion and their responses were recorded with a mouse device. Results were as follows: (1) In all cases optokinetic responses are triggered when subjects are presented with visual displays specifying either a single surface, many surfaces or a cloud of dots receding in depth. (2) The velocity of slow phases of the optokinetic nystagmus changes from matching the average velocity of a display in early phases after the onset of a stimulation to slowing down to the slowest velocity in the display, for a small number of surfaces specified by motion parallax cues. (3) Structure-from-motion is correctly detected by subjects with long detection times (between 1 and 2 s). The comparison between the slow build-up of depth perception and the slow decrease of eye pursuit velocity provides further support for the hypothesis that the control of optokinetic eye movements and the perception of depth from visual motion share common pathways up to higher cortical levels of visual processing.

Aging and reference values of the parameters in optokinetic nystagmus

Changes in optokinetic nystagmus by age were assessed, and preparation of reference values by age was made by the use of the data from 834 reference subjects. As a result, changes by age were observed at the test on optokinetic nystagmus. The reference values by these changes can be approximated with the quadratic and was considered, therefore, to be useful clinically. Four parameters were set for the test items for optokinetic nystagmus as the total number of nystagmus (NYS); the mean of eye velocity during the fast phase of nystagmus (FM); the algebraic summations of eye velocity (VEL) and amplitude (AMP) during the slow phase of nystagmus. As the process for statistical analysis, variables were divided into 7 groups, and after removing outlier (any extraneous data) in each group, changes in variables by age were assessed by the one-way analysis of variance and the method of multiple comparison (Ryan's method). As a result: 1) the age group of each variable seemed to develop into normal distribution; 2) it was presumed that change in NYS by age is less; 3-1) regarding FM, VEL and AMP, no change was observed in the variable by ages on 30s and 40s; and 3-2) however, decrease in the measured value was observed in ages on 60s along with aging. From these, the ages on 50s are the generation when the measured values of optokinetic nystagmus change. On the other hand, the reference values calculated, taking age into consideration, could be approximated with the quadratic.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in nystagmus on raising body temperature in clinically suspected and proved multiple sclerosis.

Electronystagmography was used to record the appearance or alteration of nystagmus after raising the body temperature by a heat cradle. Nystagmus was increased or provoked in 13 out of 15 patients with clinically proved multiple sclerosis, in eight out of 12 suspected cases, but in no normal controls. No positive results were obtained in 12 patients with other neurological diseases, even when nystagmus was part of the clinical picutre. The technique is simple to use and may have a role in the diagnosis of multiple sclerosis.

Cristo ocular and cristo spinal reflexes: a review after 1,000 cases of vertigo.

AbstractVertigo and dizziness may be considered spatial disorientation. This disorientation follows malfunction (following disease or injury) of the computer‐like action of the eyes, ears, proprioceptive sense, cervical spine, cerebrum, cerebellum, autonomic system or the master control in the reticular substance.It is felt that changes in nystagmus would follow injury or disease to any of these components. Studies have been reported of the establishment of parameters of cristo ocular and cristo spinal reflexes in persons with good spatial orientation. The differential diagnosis of 1,000 cases of patients with vertigo will be compared with “normals,” establishing, where possible, a differential diagnosis.

Development of the optic-vestibular coordination for adaptation to rotatory stimulation and the role of the cervical propioceptors--observation of the changes in nystagmus caused by electric stimulation of the muscle of the dorsal region of the neck during and after rotation

Development of the optic-vestibular coordination for adaptation to rotatory stimulation and the role of the cervical propioceptors--observation of the changes in nystagmus caused by electric stimulation of the muscle of the dorsal region of the neck during and after rotation

On the changes of nystagmus caused by ultrasound--produced focal lesions in the MLF of the rabbit.

The author has studied on the changes of nystagmus caused by ultrasound-produced focal lesion in the MLF of the rabbit. Results obtained are summarized as follows:(1) A diminution of adducting movements on optokinetic and vesti-bular nystagmus was observed by destroying the MLF at the level of the rostral portion of IV ventricle, while a diminution of abducting movements on vestibular nystagmus, on the contrary, was observed by destroying the MLF below the level of the trochlear nuclei.(2) In one rabbit, in which MLF was transected just below the level of the trochlear nuclei, the so-called convergence nystagmus was transitorily observed.(3) In the author's opinion, the difference between author's result and that of Bender & Weinstein (1944) seems to be due to the difference in species of the animals used.

Nystagmus: a parameter of mental function.

Nystagmographic records from an unusual case of spontaneous nystagmus probably of the central vestibular type were presented, demonstrating that nystagmus under selected conditions reflects with exquisite sensitivity certain aspects of mental functioning. Something of the process or processes monitored seems to be communicated by what is popularly indicated by such terms as “concentration,” “mental activity,” and “mental effort” and are not adequately explained by such concepts as changes in “alertness” or “attention” and “release from a central inhibition.” The importance of these mental factors lies in the additional hazard they impose on the use of quantitative changes in nystagmus for neurological diagnosis. Studies using nystagmus to demonstrate vestibular dysfunction in patient groups characterized by less than optimal cooperation must be reassessed. The usefulness of this parameter in the future study of mental function is emphasized.

On the Changes of Nystagmus Caused by Ultrasound-Produced Focal Lesions in the Brain-Stem

Results obtained are summarized as follows: (1) The presence of both the medial longitudinal fasciculus and ponto-mesencephalic reticular formation is of vital importance in the evocation of normal nystagmic reactions. (2) The ponto-mesencephalic reticular formation has the nystagmic controlling mechanism which produces a phasic rhythmic neural activity, especially the reticular formation on the level of nucleus motorius nervi trigemini plays an important role for the occurrence of vestibular nystagmus. The author infers that a nystagmic eliciting centre is located in it. (3) Optokinetic fibre tracts have no direct innervation with vestibular tracts in the brain-stem. (4) The destruction of the reticular formation just below the nucleus trochlearis causes the optokinetic inversion.