Esotropia, nystagmus and optic disk staphyloma in Donnai-Barrow syndrome / Esotropia, nistagmo e estafiloma de disco óptico na síndrome de Donnai-Barrow

ABSTRACT A 12-year-old boy with Donnai-Barrow syndrome diagnosed intra-uterus presented esotropia, high myopia, nystagmus, and optic disk staphyloma in an ophthalmologic examination. The patient had associated Fanconi syndrome and sensorineural hearing loss as well as facial manifestations as hypertelorism, downward slanting of palpebral fissures and low ear implantation. Magnetic resonance imaging revealed agenesis of the corpus callosum. To our knowledge, this is the first reported case associated with esotropia, nystagmus, and optic disk staphyloma.

RESUMO Paciente do sexo masculino, 12 anos, com diagnóstico intrauterino de síndrome de Donnai-Barrow, apresentava ao exame oftalmológico esotropia, alta miopia, nistagmo e estafiloma de disco óptico. Associado ao quadro, apresentava síndrome de Falconi e perda auditiva neurossensorial, além de alterações faciais, como hipertelorismo, inclinação inferior das fissuras palpebrais e implantação baixa das orelhas. Ressonância magnética revelou agenesia de corpo caloso. Ao nosso conhecimento, este é o primeiro caso relatado associando esotropia, nistagmo e estafiloma de disco óptico.

Effect of Viewing Conditions on Fixation Eye Movements and Eye Alignment in Amblyopia.

Purpose: Patients with amblyopia are known to have fixation instability, which arises from alteration of physiologic fixation eye movements (FEMs) and nystagmus. We assessed the effects of monocular, binocular, and dichoptic viewing on FEMs and eye alignment in patients with and without fusion maldevelopment nystagmus (FMN). Methods: Thirty-four patients with amblyopia and seven healthy controls were recruited for this study. Eye movements were recorded using infrared video-oculography during (1) fellow eye viewing (FEV), (2) amblyopic eye viewing (AEV), (3) both eye viewing (BEV), and (4) dichoptic viewing (DcV) at varying fellow eye (FE) contrasts. The patients were classified per the clinical type of amblyopia and FEM waveforms into those without nystagmus, those with nystagmus with and without FMN. Fixational saccades and intersaccadic drifts, quick and slow phases of nystagmus, and bivariate contour ellipse area were analyzed in the FE and amblyopic eye (AE). Results: We found that FEMs are differentially affected with increased amplitude of quick phases of FMN observed during AEV than BEV and during DcV at lower FE contrasts. Increased fixation instability was seen in anisometropic patients at lower FE contrasts. Incomitance of eye misalignment was seen with the greatest increase during FEV. Strabismic/mixed amblyopia patients without FMN were more likely to demonstrate a fixation switch where the AE attends to the target during DcV than patients with FMN. Conclusions: Our findings suggest that FEM abnormalities modulate with different viewing conditions as used in various amblyopia therapies. Increased FEM abnormalities could affect the visual function deficits and may have treatment implications.

Visual and Refractive Status of Children With Down's Syndrome and Nystagmus.

Purpose: Children with Down's syndrome (DS) are known to have poorer visual acuity than neurotypical children. One report has shown that children with DS and nystagmus also have poor acuity when compared to typical children with nystagmus. What has not been established is the extent of any acuity deficit due to nystagmus and whether nystagmus affects refractive error within a population with DS. Methods: Clinical records from the Cardiff University Down's Syndrome Vision Research Unit were examined retrospectively. Binocular visual acuity and refraction data were available for 50 children who had DS and nystagmus and 176 children who had DS but no nystagmus. Data were compared between the two groups and with published data for neurotypical children with nystagmus. Results: The study confirms the deficit in acuity in DS, compared to neurotypical children, of approximately 0.2 logMAR and shows a deficit attributable to nystagmus of a further 0.2 logMAR beyond the first year of life. Children with both DS and nystagmus clearly have a significant additional impairment. Children with DS have a wide range of refractive errors, but nystagmus increases the likelihood of myopia. Prevalence and axis direction of astigmatism, on the other hand, appear unaffected by nystagmus. Conclusions: Nystagmus confers an additional visual impairment on children with DS and must be recognized as such by families and educators. Children with both DS and nystagmus clearly need targeted support.

Perception of Coherent Motion in Infantile Nystagmus Syndrome.

Purpose: Research on infantile nystagmus syndrome (INS) and motion perception is limited. We investigated how individuals with INS perform coherent motion tasks. Particularly, we assessed how the null position affects their performance. Methods: Subjects with INS and controls identified the direction of coherent motion stimuli (22 subjects with INS and 13 controls) in a two-alternative forced-choice design. For subjects with INS, testing was done at the null position and 15 degrees away from it. If there was no null, testing was done at primary gaze position and 15 degrees away from primary. For controls, testing was done at primary gaze position and 20 degrees away from primary. Horizontal and vertical motion coherence thresholds were determined. Results: Subjects with INS showed significantly higher horizontal and vertical motion coherence thresholds compared with controls at both gaze positions (P < 0.001). Within the INS group, for 12 subjects with INS who had an identified null position, no differences in coherence thresholds were found between their null and 15 degrees away from it (P > 0.05). Conclusions: Coherent motion perception was impaired in subjects with INS. The null position did not significantly influence motion coherence thresholds for either horizontal or vertical motion.

Pseudo-spontaneous nystagmus in patients with lateral canal benign paroxysmal positional vertigo.

BACKGROUND: Pseudo-spontaneous nystagmus (PSN) can be detected in patients with lateral canal benign paroxysmal positional vertigo (LC-BPPV). Its frequency, and correlation with the therapeutic outcome have been less described and conflicting results have been reported. OBJECTIVE: This study aims to investigate its clinical and prognostic significance. MATERIAL AND METHOD: One hundred and eighty-four patients with LC BPPV (98 apogeotropic, 86 geotropic type) were enrolled for the study. Clinical parameters were reviewed in patients with or without PSN. The Chi-square and one way ANOVA tests were used to compare the difference between study groups. Statistical significance was set at p < .05. RESULTS: Twenty-two patients with apogeotropic (22.4%; 98/22) and 17 patients with geotropic nystagmus (19.7%; 86/17) had PSN. The incidence, age, male-female ratio, mean slow phase velocity (SPV), duration of BPPV and the rate of recurrence were not significant in patients with LC-BPPV whether they have PSN or not. CONCLUSION: Prognostic role of PSN in patients with LC BPPV seems to be questionable. SIGNIFICANCE: Appearance and disappearance of PSN with regard to head position helps to differentiate BPPV from other acute vestibular disorders. Additionally, direction of nystagmus assists to determine the site of the affected canal. However, prognostic significance is obscure.

Asymmetry and tuning shift of the cervical vestibular evoked myogenic potential indicate saccular dysfunction in idiopathic normal pressure hydrocephalus.

OBJECTIVE: The purpose of this study was to investigate the effects of excessive cerebrospinal fluid (CSF) retention on the peripheral vestibular function and the inner ear fluid in patients with idiopathic normal pressure hydrocephalus (iNPH). METHODS: In 25 patients with iNPH (14 females, age 65-88 years), cervical vestibular evoked myogenic potential (cVEMP) was measured before the spinal tap test. The asymmetry ratios (ARs) and tuning properties in 500 Hz and 1,000 Hz short-tone burst stimuli of cVEMP were evaluated. Furthermore, cVEMP was measured in an age-matched control group of 12 non-iNPH patients. RESULTS: Seven (28%) iNPH patients exhibited a cVEMP asymmetry (AR > 33%). cVEMP tuning was significantly shifted to a higher frequency in the iNPH group than in the age-matched control group. CONCLUSIONS: One-fourth of patients with iNPH had obvious saccular dysfunction. A high rate of a shift in cVEMP tuning in the iNPH group indicated that excessive CSF accumulation propagated to the endolymph and perilymph. SIGNIFICANCE: Saccular dysfunction might be one of the possible causes of imbalance in iNPH, and the shift in cVEMP tuning may be a determining factor in the diagnosis and treatment strategy.

Clinical albinism score, presence of nystagmus and optic nerves defects are correlated with visual outcome in patients with oculocutaneous albinism.

Purpose: To correlate clinical features, molecular genetic findings, and visual acuity in a cohort of patients clinically diagnosed with oculocutaneous albinism.Design: Retrospective chart reviewMethods: 58 charts met the inclusion criteria. Clinical examination, ancillary testing, and molecular genetic diagnoses were extracted. A novel clinical albinism score (CAS) was developed.Results: A least one likely pathogenic mutation was found in 44/58 (75.9%) patients. Mutations in the OCA1 gene were the most common (52.3%), followed by OCA2 (34%), OCA4 (2.3%), OA1 (6.8%), and HPS (4.5%). Thirty-four percentage of patients had a complete genotype, 41% had one mutation found and 24% had negative genetic testing. CAS was statistically significantly higher in patients with complete genotype, versus patients with one or no mutations found (p < .01). Better visual acuity was associated with lower CAS and fewer disease-causing mutations (p < .01). Foveal defects and iris transillumination were associated with a higher number of mutations (p < .01). Patients with nystagmus or anomalous optic nerves had worse visual acuity than those who did not (p < .01, p < .05).Conclusions: Patients with a complete genotype were more likely to have higher CAS. Vision loss correlated with complete phenotype and higher CAS, the presence of nystagmus and anomalous optic nerves. Patients with features of albinism in whom an incomplete genotype was found had better vision than those with complete genotype, suggesting a mild occult mutation or modifier variant. Genetic diagnosis is vital for complete diagnosis, counseling, and family planning.

Paraneoplastic cochleovestibulopathy: clinical presentations, oncological and serological associations.

OBJECTIVE: Cochleovestibulopathy is a distinguishable paraneoplastic phenotype. In this study, we evaluate clinical presentation, serological/cancer associations and outcomes of paraneoplastic cochleovestibulopathy. METHODS: Retrospective chart review of patients with hearing impairment and/or vestibulopathy who underwent serological evaluations for paraneoplastic antibodies between January 2007 and February 2021 was performed. RESULTS: Twenty-six patients were identified (men, n=23; median age, 45 years, range: 28-70). Biomarkers detected included: KLHL11-IgG| |(n=20,| |77% (coexisting LUZP4-IgG, n=8)),| ||ANNA1-IgG| | |(n=3,| |12%),| |amphiphysin-IgG|| |(n=2,| |8%)| |and| |LUZP4-IgG|| |(n=1,| |4%). Most common neoplastic association was |testicular|/|extra-testicular| |seminoma| | (n=13,| |50%).|| Hearing| impairment (bilateral, 62%) was |present| |in| |all| |patients.| |Fifteen patients (58%) had cochleovestibular dysfunction as their initial presentation before rhombencephalitis/encephalomyelitis manifestations (hearing loss, four; acute vertigo, eight; both, three). |Brain| |MRI| |demonstrated| |internal| |auditory| |canal| |enhancement| |in| |four |patients.| Audiometry commonly revealed severe-profound bilateral sensorineural hearing loss. Most patients |had| a refractory course |despite| |immunotherapy| |and/or| |cancer| |treatment|. CONCLUSION: Cochleovestibulopathy commonly presents with rapidly progressive bilateral hearing loss and/or acute vertigo. However, in some patients, these symptoms present along with or following brainstem/cerebellar manifestations. KLHL11-IgG and seminoma are the most common serological and cancer associations, respectively. Recognition of this phenotype may aid in earlier diagnosis of paraneoplastic autoimmunity and associated cancer.

Stroke Prediction Based on the Spontaneous Nystagmus Suppression Test in Dizzy Patients: A Diagnostic Accuracy Study.

OBJECTIVE: Failure of fixation suppression of spontaneous nystagmus is sometimes seen in patients with vestibular strokes involving the cerebellum or brainstem; however, the accuracy of this test for the discrimination between peripheral and central causes in patients with an acute vestibular syndrome (AVS) is unknown. METHODS: Patients with AVS were screened and recruited (convenience sample) as part of a prospective cross-sectional study in the emergency department between 2015 and 2020. All patients received neuroimaging, which served as a reference standard. We recorded fixation suppression with video-oculography (VOG) for forward, right, and left gaze. The ocular fixation index (OFI) and the spontaneous nystagmus slow velocity reduction was calculated. RESULTS: We screened 1,646 patients reporting dizziness in the emergency department and tested for spontaneous nystagmus in 148 patients with AVS. We analyzed 56 patients with a diagnosed acute unilateral vestibulopathy (vestibular neuritis) and 28 patients with a confirmed stroke. There was a complete nystagmus fixation suppression in 49.5% of patients with AVS, in 40% of patients with vestibular neuritis, and in 62.5% of patients with vestibular strokes. OFI scores had no predictive value for detecting strokes; however, a nystagmus reduction of less than 2 °/s showed a high accuracy of 76.9% (confidence interval 0.59-0.89) with a sensitivity of 62.2% and specificity of 84.8% in detecting strokes. CONCLUSIONS: The presence of fixation suppression does not rule out a central lesion. The magnitude of suppression was lower compared to patients with vestibular neuritis. The nystagmus suppression test predicts vestibular strokes accurately provided that eye movements are recorded with VOG. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that in patients with an AVS, decreased fixation suppression recorded with VOG occurred more often in stroke (76.9%) than in vestibular neuritis (37.8%).

Exploring the biomechanical responses of human cupula by numerical analysis of temperature experiments.

The vestibular receptor of cupula acts an important role in maintaining body balance. However, the cupula buried in the semicircular canals (SCCs) will be destroyed if it is detached from the relevant environment. The mechanical properties of human cupula still remain ambiguous. In this paper, we explored the cupula responses changing with temperature by experiments and numerical simulation of SCCs model. We obtained 3 volunteers' nystagmus induced by constant angular acceleration when the temperature of volunteers' SCCs was 36 °C and 37 °C respectively. The slow-phase velocity of 3 volunteers decreased by approximately 3°/s when the temperature of SCCs reduced by 1 °C, which corresponded to the reduction of cupula deformation by 0.3-0.8 µm in the numerical model. Furthermore, we investigated the effects of the variation of endolymphatic properties induced by temperature reduction on cupula deformation through numerical simulation. We found that the decrease of cupula deformation was not caused by the change of endolymphatic properties, but probably by the increase of cupula's elastic modulus. With the temperature reducing by 1 °C, the cupula's elastic modulus may increase by 6-20%, suggesting that the stiffness of cupula is enhanced. This exploration of temperature characteristic of human cupula promotes the research of alleviating vestibular diseases.

Paraneoplastic Progressive Downbeat Nystagmus, Ataxia and Sensorineural Hearing Loss due to the ANTI-Kelch-11 Protein Antibody.

ABSTRACT: A 45-year-old man with a history of testicular seminoma treated 8 years earlier presented with chronic progressive truncal and limb ataxia, progressive sensorineural hearing loss, and episodic vertigo. Eye movement and neuro-otology examinations showed localizing abnormalities to the bilateral cerebellar flocculus, vermis, and bilateral cerebellar hemispheres. Audiometric testing showed bilateral symmetric sensorineural hearing loss. There was a normal MRI of the brain. Cerebrospinal fluid (CSF) showed modest lymphocytic pleocytosis, and there was an elevated serum choriogonadotrophic hormone. An abdominal CT scan showed a solitary, large retroperitoneal lymph node, and histopathologic examination of the node biopsy showed granulomatous inflammation without microorganisms; eventually, immunohistochemical markers confirmed the diagnosis of metastatic seminoma. Although normal neuroimaging and inflammatory CSF reaction suggested a paraneoplastic etiology, the initial paraneoplastic antibody testing was negative. Subsequent investigation identified a positive kelch-11 protein antibody, thus confirming the paraneoplastic connection between the metastatic seminoma and the subacute neurologic-cochleovestibular syndrome.

Efficacy of Yokukansan, a traditional Japanese herbal medicine, in patients with dizziness and irritability.

OBJECTIVE: Irritability is an emotional stress symptom that causes or exacerbates dizziness. Antidepressants may be helpful for some conditions that are accompanied by irritability; however, they do not completely inhibit irritability. Yokukansan (YKS), a traditional Japanese herbal medicine, has been used for neurosis, insomnia, and children's irritability and night crying. The study investigated the efficacy of YKS in nystagmus in patients with chronic dizziness and irritability. METHODS: Twenty-two cases with chronic dizziness and irritability were reviewed retrospectively. The patients were divided into two groups: control patients (0-7 days of treatment) and YKS-treated patients (YKS cases; >7 days of treatment). Dizziness before and during (after, in the controls) YKS treatment was evaluated by scoring the nystagmus intensity on a 5-point scale. The average scores were calculated within a maximum of 6 months before and during or after treatment. The normalized scores were also calculated. The optimal treatment regimen was calculated via receiver operating characteristic (ROC) curve analysis. RESULTS: There were six control cases (1 male, 5 females; mean age: 59.5 years). There were 16 YKS cases (3 males, 13 females; mean age: 61.8 years). While the group mean nystagmus intensity scores significantly decreased from 1.18 to 0.73 in the YKS cases, it did not change in the control cases. The group mean of the normalized nystagmus intensity scores during treatment was 0.73 in the YKS cases. The results of the ROC curve analysis indicated the optimal cut-off period of the YKS treatment was 10 days. CONCLUSION: The oral administration of YKS for more than 10 days was optimal. The treatments with YKS could be a good option for the treatments of vertigo.

Surgical interventions for infantile nystagmus syndrome.

BACKGROUND: Infantile nystagmus syndrome (INS) is a type of eye movement disorder that can negatively impact vision. Currently, INS cannot be cured, but its effects can potentially be treated pharmacologically, optically, or surgically. This review focuses on the surgical interventions for INS. Despite the range of surgical interventions available, and currently applied in practice for the management of INS, there is no clear consensus, and no accepted clinical guidelines regarding the relative efficacy and safety of the various treatment options. A better understanding of these surgical options, along with their associated side effects, will assist clinicians in evidence-based decision-making in relation to the management of INS. OBJECTIVES: To assess the efficacy and safety of surgical interventions for INS. SEARCH METHODS: We searched CENTRAL, MEDLINE Ovid, Embase Ovid, ISRCTN registry, ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) to 3 July 2020, with no language restrictions. SELECTION CRITERIA: We included randomised controlled trials (RCTs) studying the efficacy and safety of surgical options for treating INS. DATA COLLECTION AND ANALYSIS: Our prespecified outcome measures were the change from baseline in: binocular best-corrected distance visual acuity; head posture; amplitude, frequency, intensity, and foveation period durations of the nystagmus waveform; visual recognition times; quality of life and self-reported outcome measures; incidence of adverse effects with a probable causal link to treatment; and permanent adverse effects after surgery. Two review authors independently screened titles and abstracts and full-text articles, extracted data from eligible RCTs, and judged the risk of bias using the Cochrane tool. We reached consensus on any disagreements by discussion. We summarised the overall certainty of the evidence using the GRADE approach. MAIN RESULTS: We only identified one eligible RCT (N = 10 participants), undertaken in India. This trial randomised participants to receive either a large retro-equatorial recession of the horizontal rectus muscle of 9 mm on the medial rectus and 12 mm on the lateral rectus, or a simple tenotomy and resuturing of the four horizontal rectus muscles. We did not identify any RCTs comparing a surgical intervention for INS relative to no treatment. In the single eligible RCT, both eyes of each participant received the same intervention. The participants' age and gender were not reported, nor was information on whether participants were idiopathic or had sensory disorders. The study only included participants with null in primary position and did not explicitly exclude those with congenital periodic alternating nystagmus. The study did not report funding source(s) or author declaration of interests. The evaluation period was six months. We judged this study at low risk for sequence generation and other sources of bias, but at high risk of bias for performance and detection bias. The risk of bias was unclear for selection bias, attrition bias, and reporting bias. There is very uncertain evidence about the effect of the interventions on visual acuity and change in amplitude, frequency, and intensity of the nystagmus waveform. We were unable to calculate relative effects due to lack of data. None of the participants in either intervention group reported adverse effects at six-month follow-up (very low-certainty evidence). There was no quantitative data reported for quality of life, although the study reported an improvement in quality of life after surgery in both intervention groups (very low-certainty evidence). Change in head posture, foveation period durations of the nystagmus waveform, visual recognition times, and permanent adverse effects after surgery were not reported in the included study. We judged the certainty of the evidence, for both the primary and secondary efficacy outcomes, to be very low. Due to a lack of comprehensive reporting of adverse events, there was also very low-certainty of the safety profile of the evaluated surgical interventions in this population. As such, we are very uncertain about the relative efficacy and safety of these interventions for the surgical management of INS. AUTHORS' CONCLUSIONS: This systematic review identified minimal high-quality evidence relating to the efficacy and safety of surgical interventions for INS. The limited availability of evidence must be considered by clinicians when treating INS, particularly given these procedures are irreversible and often performed on children. More high-quality RCTs are needed to better understand the efficacy and safety profile of surgical interventions for INS. This will assist clinicians, people with INS, and their parents or caregivers to make evidence-based treatment decisions.

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.

Central nystagmus in progressive supranuclear palsy: A neglected clinical feature?

BACKGROUND: Progressive supranuclear palsy (PSP) features parkinsonism characterized by early postural instability, falls and prominent eye movement abnormalities that consist of saccadic slowing, followed by gaze limitation. Nystagmus is not considered typical for PSP, being more commonly associated with multiple system atrophy. OBJECTIVES: To describe the prevalence and phenomenology of nystagmus in patients with PSP. METHODS: 42 patients with probable PSP underwent detailed clinical eye movement examination. Patients with nystagmus performed video-nystagmography. T-test, Chi-Square test and Wilcoxon signed-rank test were used to test differences in demographic data, disease duration and PSP subtype between patients with and without nystagmus, and for analysis of video-nystagmographic data. RESULTS: Among 42 patients with PSP, we identified 15 patients (35,7%) with gaze-evoked nystagmus, predominantly horizontal. Clinically, 10/15 patients had symmetrical or asymmetrical gaze - evoked nystagmus (Type 1), while 5/15 patients had dissociated gaze-evoked nystagmus related to internuclear ophthalmoplegia (Type 2). Nystagmus and eye movement abnormalities were further characterized by video-nystagmography. There was no significant difference in age, disease duration or PSP subtypes between patients with and without nystagmus. CONCLUSION: Central nystagmus is present in more than a third of patients with progressive supranuclear palsy. It may present as symmetrical or asymmetrical gaze-evoked nystagmus or as dissociated gaze-evoked nystagmus related to internuclear ophthalmoplegia and probably arises from neurodegeneration of the neural integrator. Nystagmus in PSP has been a hitherto under-described feature and its presence should not deter clinicians from a diagnosis of PSP.

The Clinical and Imaging Profile of Skew Deviation: A Study of 157 Cases.

BACKGROUND: Skew deviation, a vertical misalignment of the eyes caused by a lesion in the vestibulo-ocular pathway, is a common manifestation of brainstem dysfunction, yet comprehensive information about its clinical profile is lacking. The aim of this study was to document presenting symptoms, causes, ocular alignment features, accompanying neurologic signs, pertinent brain imaging abnormalities, and measures used to relieve diplopia. METHODS: We searched the electronic medical records text from 2000 to 2018 for "skew" or "skew deviation" at a tertiary care academic center, including only patients diagnosed under supervision of faculty neuro-ophthalmologists. After excluding patients with features suggesting an imitator of skew deviation, we collected data useful in answering the selected clinical issues. RESULTS: In a cohort of 157 patients, vertical misalignment ranged between 1 and 30 prism diopters (PD) (median 5 PD) and was comitant in 100 (64%) patients. Diplopia was reported by 87% and blurred vision by 11% of patients. Blurred vision was more common when vertical misalignment was less than 3 PD. At least one accompanying neurologic sign was present in 133 (85%) patients, most often nystagmus, followed by gaze paresis, ataxia, saccadic pursuit, and internuclear ophthalmoplegia. Stroke affecting the thalamus, brainstem, or cerebellum accounted for 82 (52%) of cases. Stroke was usually ischemic, mostly unprovoked, but also occurring after intracranial or extracranial surgical procedures. Brainstem tumor and operative injury caused most of the remaining cases. A subgroup of 17 (11%) patients had skew deviation as the only new clinical sign and had no pertinent brain imaging abnormalities. Resolution of skew deviation, documented in 58 (42%) of 137 patients who had at least one follow-up visit, usually occurred within 3 months, but sometimes not until after 12 months. Of 110 patients who still had diplopia on follow-up examinations, the diplopia was successfully relieved with prism spectacles in 68 (62%). The cause of the skew deviation, amount of vertical misalignment, and degree of incomitance did not predict the success in relieving diplopia. Accompanying neurologic signs, including ataxia, endured in 44% of patients and were often more debilitating than the diplopia of skew deviation. CONCLUSIONS: The amplitude of misalignment in skew deviation varies widely but is generally 5 PD or less. When misalignment is 3 PD or less, patients report blurred vision rather than diplopia. Skew deviation is usually accompanied by other neurologic signs reflecting brainstem dysfunction. Yet there is a small subgroup in which vertical misalignment is an isolated sign, and there are no supporting brain imaging abnormalities. The main cause of skew deviation is ischemic stroke, which affects not only the brainstem but also the thalamus. Diplopia from skew deviation frequently persists, in which case prism spectacles may be successful in palliating it. Accompanying neurologic signs, especially ataxia, may outlast skew deviation and be more debilitating.

Sparse classification of discriminant nystagmus features using combined video-oculography tests and pupil tracking for common vestibular disorder recognition.

Vertigo is a common sign related to a problem with the brain or vestibular system. Detection of ocular nystagmus can be a support indicator to distinguish different vestibular disorders. In order to get reliable and accurate real time measurements from nystagmus response, video-oculography (VOG) plays an important role in the daily clinical examination. However, vestibular diseases present a large diversity in their characteristics that leads to many complications for usual analysis. In this paper, we propose a novel automated approach to achieve both selection and classification of nystagmus parameters using four tests and a pupil tracking procedure in order to give reliable evaluation and standardized indicators of frequent vestibular dysfunction that will assist clinicians in their diagnoses. Indeed, traditional tests (head impulse, caloric, kinetic and saccadic tests) are applied to obtain clinical parameters that highlight the type of vertigo (peripheral or central vertigo). Then, a pupil tracking method is used to extract temporal and frequency nystagmus features in caloric and kinetic sequences. Finally, all extracted features from the tests are reduced according to their high characterization degree by linear discriminant analysis, and classified into three vestibular disorders and normal cases using sparse representation. The proposed methodology is tested on a database containing 90 vertiginous subjects affected by vestibular Neuritis, Meniere's disease and Migraines. The presented technique highly reduces labor-intensive workloads of clinicians by producing the discriminant features for each vestibular disease which will significantly speed up the vertigo diagnosis and provides possibility for fully computerized vestibular disorder evaluation.