Oculomotor Dysfunctions Research Articles

Artificial intelligence-assisted oculo-gait measurements for cognitive impairment in cerebral small vessel disease.

Oculomotor and gait dysfunctions are closely associated with cognition. However, oculo-gait patterns and their correlation with cognition in cerebral small vessel disease (CSVD) remain unclear. Patients with CSVD from a hospital-based cohort (n = 194) and individuals with presumed early CSVD from a community-based cohort (n = 319) were included. Oculo-gait patterns were measured using the artificial intelligence (AI) -assisted 'EyeKnow' eye-tracking and 'ReadyGo' motor evaluation systems. Multivariable linear and logistic regression models were employed to investigate the association between the oculo-gait parameters and cognition. Anti-saccade accuracy, stride velocity, and swing velocity were significantly associated with cognition in both patients and community dwellers with CSVD, and could identify cognitive impairment in CSVD with moderate accuracy (area under the curve [AUC]: hospital cohort, 0.787; community cohort, 0.810) after adjusting for age and education. The evaluation of oculo-gait features (anti-saccade accuracy, stride velocity, and swing velocity) may help screen cognitive impairment in CSVD. Oculo-gait features (lower anti-saccade accuracy, stride velocity, and swing velocity) were associated with cognitive impairment in cerebral small vessel disease (CSVD). Logistic model integrating the oculo-gait features, age, and education level moderately distinguished cognitive status in CSVD. Artificial intelligence-assisted oculomotor and gait measurements provide quick and accurate evaluation in hospital and community settings.

Rehabilitation Oculomotor Screening Evaluation (ROSE)-A Proof-of-Principle Study for Acquired Brain Injuries.

Background/Objectives: Acquired brain injury (ABI) is a major cause of global disability. Many ABI patients exhibit oculomotor dysfunctions that impact their daily life and rehabilitation outcomes. Current clinical tools for oculomotor function (OMF) assessment are limited in their usability. In this proof-of-principle study, we aimed to develop an efficient tool for OMF screening and to assess the feasibility, acceptability, and relevance in a small sample of ABI and control participants. Methods: We created the Rehabilitation Oculomotor Screening Evaluation (ROSE) by reviewing existing OMF assessments. ROSE was pilot-tested on ABI patients (n = 10) and age-matched controls (n = 10). Data regarding the characteristics of the assessment, such as the duration, level of participant comprehension, and participant experience were also collected. Results: ROSE takes <20 min (x¯ = 12.5), is easy to complete (agreement x¯ = 4.6/5), and is well-accepted (x¯ = 4.8/5). Patients scored higher in all subtests and total score (x¯ = 34.8 for ABI vs. 8.9 for controls). Most subtests did not provoke any symptoms, especially for controls. There were no significant between-group differences in symptom provocation. This proof-of-principle study shows that ROSE is feasible, acceptable, and relevant for adult ABI patients. Conclusions: ROSE needs further evaluation for reliability testing and validation in larger samples and diverse neurological conditions. Establishing norms for various ages, sexes, and populations should be considered for the deployment of ROSE as an OMF clinical tool.

Nucleus accumbens degeneration in spinocerebellar ataxia type 2: a preliminary study.

Spinocerebellar ataxia type 2 (SCA2) exhibits mainly cerebellar and oculomotor dysfunctions but also, frequently, cognitive impairment and neuropsychological symptoms. The mechanism of the progression of SCA2 remains unclear. This study aimed to evaluate longitudinal structural changes in the brains of SCA2 patients based on atrophy rate. The OpenNeuro Dataset ds001378 was used. It comprises the demographic data and two magnetic resonance images each of nine SCA2 patients and 16 healthy controls. All structural images were preprocessed using FreeSurfer software, and each region's bilateral volume was summed. Atrophy rates were calculated based on the concept of symmetrised percent change and compared between SCA2 patients and healthy controls using non-parametric statistics. As post hoc analysis, correlation analysis was performed between infratentorial volume ratio and the accumbens area atrophy rates in SCA2 patients. There were no significant differences between groups for age, gender, and the time between scans. Statistical analysis indicated a significantly larger atrophy rate of the accumbens area in SCA2 patients than in controls. Additionally, the infratentorial volume ratio and accumbens area atrophy rates showed moderate negative correlation. This study found that nucleus accumbens (NAc) atrophy was significantly accelerated in SCA2 patients. Anatomically, the NAc is densely connected with infratentorial brain regions, so it is reasonable to posit that degeneration propagates from the cerebellum and brainstem to the NAc and other supratentorial areas. Functionally, the NAc is essential for appropriate behaviour, so NAc degeneration might contribute to neuropsychological symptoms in SCA2 patients.

Impact of Concussions on Postural Stability Performance Using the Head Shake-Sensory Organization Test.

A concussion is a traumatic brain injury that can result in vestibular and oculomotor dysfunctions. The Head Shake-Sensory Organization Test was developed from the original Sensory Organization Test to measure a subject's ability to maintain balance while moving their head. The purpose of this study was to compare the performance of adults with no history of concussion to those with a history of concussion on the Head Shake-Sensory Organization Test to determine if long-standing balance deficits are present after concussion. Cross-sectional study. Subjects with a history of concussion and healthy normal controls completed the Dizziness Handicap Inventory, the Activities-Specific Balance Confidence Scale, the sensory organization test, the head shake SOT, and the Foam Head Shake-Sensory Organization test in a single testing session. Scores were analyzed for differences between the two groups. Twenty-five participants (nine patients with history of concussion and 16 healthy controls; mean age, 21.08±4.10 years) completed testing. The equilibrium scores in both groups significantly decreased with more complex tasks. Furthermore, the concussion group had significantly worse equilibrium scores than the control group during the Head Shake (p = 0.007) and Foam Head Shake-Sensory Organization Test (p = 0.002) tasks but not during the Sensory Organization Test task. Adding head shake and foam cushion conditions to postural stability tests improves sensitivity in detecting balance deficits in individuals with a concussion. 3.

Diagnosis of Lupus Cerebritis with Balint Syndrome: A Unique Case Report

Introduction: Among the wide variety of clinical manifestations in Systemic Lupus Erythematosus (SLE), cognitive dysfunction (CD) is a subtle finding, where the reported prevalence ranges from 3-88% due to CD assessment inconsistencies and challenges with SLE correlations. Cognitive dysfunction may also be a cornerstone element for a diagnosis of Neuropsychiatric Systemic Lupus Erythematosus (NP-SLE). We present a case of Lupus Cerebritis displaying seizures and oculomotor dysfunctions referred to as Balint Syndrome. To our knowledge, no publications to date have shown a correlation between Lupus Cerebritis and Balint Syndrome. Case Report: A 35-year-old female with a history of lupus, seizures, and migraines presented complaining of a severe headache associated with vomiting. The patient stated the onset of her symptoms was three days prior and had been worsening. While in the emergency room, the patient had a generalized tonic-clonic seizure lasting around 2 minutes at which point neurology was consulted for seizure management. The patient had been seen about a year prior for similar complaints and was started on Keppra to control her epilepsy. The patient was seizure free for about 6 months so Keppra was discontinued. Discussion: A wide array of symptoms are associated with Lupus Cerebritis, which is a rare manifestation following a diagnosis of SLE. Our patient was having seizures and complaints of migraine with severe Balint Syndrome consisting of oculomotor apraxia, optic ataxia, and simultagnosia. Due to some patients’ rapid decline following a diagnosis of SLE and the complex diversity of symptoms, it is crucial to prevent organ failure by treating them immediately, and furthermore, to equip and educate clinicians in identifying atypical presentations. Conclusion: Due to the complexity of autoimmune diseases, patients may present with a plethora of symptomatology, ranging from mild to severe, making a thorough medical history and physical examination imperative elements of a complete workup. Since NP-SLE is a nuanced diagnosis requiring specific management, it is essential to have close follow-ups with neurology.

Technologies Supporting Screening Oculomotor Problems: Challenges for Virtual Reality

Oculomotor dysfunctions (OMDs) are problems relating to coordination and accuracy of eye movements for processing visual information. Eye-tracking (ET) technologies show great promise in the identification of OMDs. However, current computer technologies for vision screening are specialized devices with limited screen size and the inability to measure depth, while visual field and depth are important information for detecting OMDs. In this experimental study, we examine the possibilities of immersive virtual reality (VR) technologies compared with laptop technologies for increased user experiences, presence, immersiveness, and the use of serious games for identifying OMDs. The results present increased interest in VR-based screening, motivating users to focus better using VR applications free from outside distractions. These limitations currently include lower performance and confidence in results of identifying OMDs with the used HMDs. Using serious games for screening in VR is also estimated to have great potential for developing a more robust vision screening tool, especially for younger children.

Vision impairment is common in non-hospitalised patients with post-COVID-19 syndrome

ABSTRACT Clinical relevance Vision-related problems can be part of longstanding sequelae after COVID-19 and hamper the return to work and daily activities. Knowledge about symptoms, visual, and oculomotor dysfunctions is however scarce, particularly for non-hospitalised patients. Clinically applicable tools are needed as support in the assessment and determination of intervention needs. Background The purpose of this study was to evaluate vision-related symptoms, assess visual and oculomotor function, and to test the clinical assessment of saccadic eye movements and sensitivity to visual motion in non-hospitalised post-COVID-19 outpatients. The patients (n = 38) in this observational cohort study were recruited from a post-COVID-19 clinic and had been referred for neurocognitive assessment. Methods Patients who reported vision-related symptoms reading problems and intolerance to movement in the environment were examined. A structured symptom assessment and a comprehensive vision examination were undertaken, and saccadic eye movements and visual motion sensitivity were assessed. Results High symptom scores (26–60%) and prevalence of visual function impairments were observed. An increased symptom score when reading was associated with less efficient saccadic eye movement behaviour (p < 0.001) and binocular dysfunction (p = 0.029). Patients with severe symptoms in visually busy places scored significantly higher on the Visual Motion Sensitivity Clinical Test Protocol (p = 0.029). Conclusion Vision-related symptoms and impairments were prevalent in the study group. The Developmental Eye Movement Test and the Visual Motion Sensitivity Clinical Test Protocol showed promise for clinical assessment of saccadic performance and sensitivity to movement in the environment. Further study will be required to explore the utility of these tools.

Developmental Eye Movement (DEM) and King-Devick (K-D) Performance in Multiple Sclerosis.

Eye movement disorders have been reported in patients with multiple sclerosis (MS) as saccadic disturbances. Several methods have been described for the assessment of saccades, including the K-D and DEM tests. The performance of these tests also involves attention, language, and other brain areas which have been reported to be altered in MS patients. The aim of the study was to determine how developmental eye movement (DEM) and King-Devick (K-D) tests are affected in MS-patients. It was also to analyze whether a resolved episode of optic neuritis (ON) has a negative influence. Subjects with MS showed worse outcomes (higher times) in DEM test (72 (26) s and a K-D test (56 (22) s compared to healthy subjects (64 (7) s and 55 (11) s, respectively). However, a previous ON episode did not worsen the MS-times of DEM (80 (33) s or of K-D (62 (33) s. Horizontal saccades with the DEM showed differences between subjects with MS (with and without ON) and healthy ones (p < 0.05), whereas no such differences were found in the vertical saccades. According to the DEM instructions, MS patients would present heterogeneous oculomotor and non-visual disturbances. Regarding the K-D test, only the third card (the most complex one) showed differences (p < 0.05) between groups. These tests can capture impairment of attention, language, and other areas that correlate with suboptimal brain function in addition to the oculomotor dysfunctions present in subjects with MS.

Remediation of Visual Snow (VS) and Related Phenomena in a Neuro-Optometric Practice: A Retrospective Analysis

INTRODUCTION: Visual Snow (VS) and the Visual Snow Syndrome (VSS) represent relatively new and important medical and neuro-optometric diagnoses. While there is much information dealing with their defining characteristics and diagnosis, there is a relative paucity of information dealing with therapeutic intervention. Methods: In the present investigation, a retrospective analysis of 27 patients (ages 9-55 years, mean of 28 years) with documented VSS was performed with respect to treatment of the visual snow, palinopsia, and the newly-discovered versional oculomotor dysfunctions in a private, optometric practice setting. Patients were provided a comprehensive neurooptometric and binocular vision examination, as well as completed the VSS Symptom Survey. Treatment: they were given a selection of 5 BPI and FL-41 chromatic tints to assess using a simple clinical comparison protocol for the VS; they were provided a range of saccadic tests to remediate the common finding of palinopsia; and they were given optometric vision therapy to remediate the common, versional oculomotor problems. Results: Chromatic filters were prescribed in 24 of the 27 patients for their VS, with symptom reduction of at least 50%. Reduction of the palinopsia by 50-65% was found in all 23 patients who had palinopsia following the saccadic therapy. 23 of the 27 were given oculomotor-based vision therapy for their versional deficits (i.e., OMD), and marked symptom reduction was reported in all. Conclusion: This is the first study to demonstrate that neuro-optometric rehabilitation (NOR) provided successful remediation of the problems of VS, palinopsia, and OMD in symptomatic, clinical patients with VSS.

Multimodal invivo staging in amyotrophic lateral sclerosis using artificial intelligence.

BackgroundThe underlying neuropathological process of amyotrophic lateral sclerosis (ALS) can be classified in a four‐stage sequential pTDP‐43 cerebral propagation scheme. Using diffusion tensor imaging (DTI), in vivo imaging of these stages has already been shown to be feasible for the specific corticoefferent tract systems. Because both cognitive and oculomotor dysfunctions are associated with microstructural changes at the brain level in ALS, a cognitive and an oculomotor staging classification were developed, respectively. The association of these different in vivo staging schemes has not been attempted to date.MethodsA total of 245 patients with ALS underwent DTI, video‐oculography, and cognitive testing using Edinburgh Cognitive and Behavioral ALS Screen (ECAS). A set of tract‐related diffusion metrics, cognitive, and oculomotor parameters was selected for further analysis. Hierarchical and k‐means clustering algorithms were used to obtain an optimal cluster solution.ResultsAccording to cluster analysis, differentiation of patients with ALS into four clusters resulted: Cluster A showed the highest fractional anisotropy (FA) values and thereby the best performances in executive oculomotor tasks and cognitive tests, whereas cluster D showed the lowest FA values, the lowest ECAS scores, and the worst executive oculomotor performance across all clusters. Clusters B and C showed intermediate results regarding parameter values.DiscussionIn a multimodal dataset of technical assessments of brain structure and function in ALS, an artificial intelligence‐based cluster analysis showed high congruence of DTI, executive oculomotor function, and neuropsychological performance for mapping in vivo correlates of neuropathological spreading.

How to assess visual function in acquired brain injury-Asking is not enough.

BackgroundAcquired brain injury affects many brain areas and causes a range of dysfunctions including vision‐related issues. These issues can have negative impacts on rehabilitation progress and activities of daily life but may easily be overlooked. There is no common recommendation about how to assess visual impairments after ABI. The purpose of this study was to estimate the frequency of objectively measures oculomotor dysfunctions, and also how these findings are related to two inventories intended to support detection of visual impairment.MethodsThe study was cross‐sectional and included 73 outpatients. In addition to the standard evaluation program, the patients went through a comprehensive optometric examination. The inventories used were the Vision Interview (VI) and the Convergence Insufficiency Symptom Survey (CISS).ResultsAll three types of examinations showed a high proportion vision‐related symptoms. Fusion vergence was the most common objectively measured finding, 83%. There were seven statistically significant associations between five VI items and five visual deficits. The strength of associations was moderate (Phi 0.261–0.487, p < .05). The sensitivity and specificity of the CISS were moderate.ConclusionWe found high percentages of the patients with visual symptoms and dysfunctions. Due to the complexity of visual symptoms and functional deficits in ABI, we find it necessary to combine both symptom assessment and vision examination in order to capture visual function issues.

Tendon elongation with bovine pericardium in strabismus surgery\u2014indications beyond Graves\u2019 orbitopathy

BackgroundFor some patients with complex ocular motility disorders, conventional strabismus surgery is insufficient. Surgery with tendon elongation allows correction of larger angles and maintains a sufficient arc of contact for rectus muscles. This study reports results for tendon elongation with bovine pericardium (Tutopatch®) in indications other than Graves’ orbitopathy in which it is already widely used.MethodsWe reviewed the records of all patients who underwent surgery with Tutopatch® in our institution. Angles of squint and head postures were analyzed preoperatively, on the first postoperative day, and in the long term (median 9 weeks after the operation). Patients with Graves’ orbitopathy were excluded.ResultsFrom 2011 to 2018, the procedures on 58 eyes of 54 patients (35 females, median age 35 years (3–75)) met the inclusion criteria. Horizontal rectus muscle surgery (53 eyes) was conducted on patients with residual strabismus (13), Duane’s retraction syndrome with eso- (type I: 16)/exodeviation (type II: 2, type III: 1), 6th (7)/3rd nerve palsy (7), Möbius syndrome (2), congenital fibrosis of the extraocular muscles type 3A (CFEOM3A, TUBB3 mutation) (4), and orbital apex syndrome (1). Vertical rectus muscle surgery (5 eyes) was conducted on patients with myasthenia (1), vertical tropia after orbital floor fracture (1), CFEOM1 (2), and Parry-Romberg syndrome (1). 42 eyes had prior eye muscle surgery (1–5 procedures, median 1). Out of 45 patients with postoperative long-term data, 43 showed an angle reduction. Fifty-one percent had an angle of 10Δ (prism diopter) or less, one had a significant over-effect, and 10 had revision surgery. For the heterogeneous group of residual eso- and exotropias, the median absolute horizontal angle was reduced from 35Δ (16 to 45Δ) to 9Δ (0 to 40Δ), for Duane’s retraction syndrome from 27.5Δ (9 to 40Δ) to 7Δ (0 to 40Δ), and for sixth and third nerve palsies from 43Δ (20 to 75Δ) to 18Δ (4 to 40Δ). For 3 patients with vertical rectus muscle surgery, the median absolute vertical angle was reduced from 30Δ (20 to 45Δ) to 4Δ (1 to 22Δ). The motility range was shifted in the direction contrary to the elongated muscle in all subgroups. A considerable reduction of the excursion into the field of action of the elongated muscle had to be registered.ConclusionsStrabismus surgery with bovine pericardium introduces new surgical options for complicated revisions and for rare and complex oculomotor dysfunctions. Yet, it has to be recognized that this type of surgery aiming at maximum effects, despite preservation or restitution of the arc of contact, leads to reduction of the excursion into the field of action of the elongated muscle. Furthermore, dose finding can be difficult depending on the underlying pathology and more than one intervention might be necessary for optimal results.

The saccade main sequence revised: A fast and repeatable tool for oculomotor analysis

Saccades are rapid ballistic eye movements that humans make to direct the fovea to an object of interest. Their kinematics is well defined, showing regular relationships between amplitude, duration, and velocity: the saccadic ’main sequence’. Deviations of eye movements from the main sequence can be used as markers of specific neurological disorders. Despite its significance, there is no general methodological consensus for reliable and repeatable measurements of the main sequence. In this work, we propose a novel approach for standard indicators of oculomotor performance. The obtained measurements are characterized by high repeatability, allowing for fine assessments of inter- and intra-subject variability, and inter-ocular differences. The designed experimental procedure is natural and non-fatiguing, thus it is well suited for fragile or non-collaborative subjects like neurological patients and infants. The method has been released as a software toolbox for public use. This framework lays the foundation for a normative dataset of healthy oculomotor performance for the assessment of oculomotor dysfunctions.

Oculomotor Dysfunctions: Evidence-Based Practice

David P Pinero is supported by the Ministry of Economy, Industry and Competitiveness of Spain within the program Ramon y Cajal, RYC-2016-20471.

Evaluation of Vision in Gnathological and Orthodontic Patients with Temporomandibular Disorders: A Prospective Experimental Observational Cohort Study.

ABSTRACTObjectives:Temporomandibular disorders (TMDs), orthodontic diseases, and vision dysfunctions seem to be strictly related. The purpose of this study was to prove the relationship, to evaluate the prevalence and the distribution of vision defects in dysfunctional and orthodontic patients, and to establish the type of the relationship.Materials and Methods:A total of 100 patients with TMDs were selected and studied through epidemiological analyses of the following factors: gnathological parameters (temporomandibular joint pathologies according to Diagnostic Criteria for Temporomandibular Disorders); occlusal and skeletal parameters (overjet, overbite, dental class, transversal discrepancies, and mandibular asymmetry); and orthoptic parameters (refractive defects and oculomotor diseases). A prospective experimental observational cohort study was conducted. A comparison with the average frequency of vision defects of the Italian population was performed. The prevalence of vision defects was evaluated. All gnathological and orthodontic parameters were associated with the orthoptic ones. A descriptive and statistical analysis of the data was carried out with the Statistical Package for the Social Sciences software; z test (P < 0.05), frequency analysis (frequency >50%), chi-square test, and Student’s t test (P < 0.05) were performed. The scientific consistency was evaluated by using the scientific criteria of Bradford Hill.Results:The comparison with the Italian population showed a higher frequency of refractive defects in the study sample (P < 0.001). The most frequent vision defects were phorias (92%) and tropia (3%). The increased frequency of ocular convergence reduction in the presence of disc displacement with reduction was significant (n = 28; 60%; P < 0.05). In the presence of asymmetry, low frequencies of astigmatism (n = 18; 30%) were observed compared to its absence (n = 22; 54%) (P < 0.05) and high frequencies of motor ocular deviations (n = 59; 100%) were observed compared to its absence (n = 36; 88%) (P < 0.05). In the presence of headache, low frequencies of emmetropia (n = 13; 22%) and higher frequencies of hyperopia (n = 18; 30%) were observed (P < 0.05). Two of five scientific criteria of Bradford Hill were met.Conclusion:It seems to emerge a possible positive relationship between TMD and vision defects. In particular, the most interesting associations were found between functional or skeletal orthognathic alterations and oculomotor dysfunctions. However, it was not possible to establish the type of relationship.

Postconcussion: Receded Near Point of Convergence is not Diagnostic of Convergence Insufficiency

To determine the frequency of occurrence of receded near point of convergence (NPC) in patients with chronic concussion-related symptoms and in those with receded NPC to enumerate the frequency of convergence insufficiency and other oculomotor disorders. Retrospective cross-sectional study. Clinic charts were retrospectively reviewed for the prior 3.5 years to identify all patients < 21 years old who were > 28days postconcussion, had chronic concussion-related symptoms, had normal visual acuity, and had received a comprehensive sensorimotor examination. The frequency of receded NPC and oculomotor diagnoses were determined. Of the 83 eligible patients, 74 (89%) had receded NPC. Of these, 70 (95%) had oculomotor disorders; 30 (41%) had disorders of accommodation only; 21 (28%) had convergence insufficiency and accommodation deficits; and 6 (8%) had convergence insufficiency only. Six (8%) had a convergence deficit other than convergence insufficiency (all with concurrent accommodative disorders); 4 (5%) had both a nonspecific vergence dysfunction and accommodation deficits; 2 (3%) had convergence excess only; and 1 (1%) had both convergence excess and accommodative deficits. A receded NPC was present in the majority of young patients with chronic postconcussion symptoms. Associated with numerous underlying oculomotor dysfunctions, the clinical finding of a receded NPC is not synonymous with the diagnosis of convergence insufficiency. Because treatment options for the various oculomotor dysfunctions differ, it is prudent that these patients undergo a thorough examination of their vergence and accommodative systems so that an accurate diagnosis can be made and appropriate treatment prescribed.

Acts Aspect to the result of a cerebral hemorrhagic supratentorial session on the basics of analisys in the tentorial wedge

Cerebral transtentorial herniation determinates the course of progressive focal supratentorial impairments and acute hemorrhagic hemispheric stroke. Clinical and pathomorphological comparisons were done in patients with acute hemorrhagic hemispheric stroke. The following predictors of hemorrhagic hemispheric stroke lethal outcome were verified: 1) acute onset of coma in association with oculomotor dysfunctions; 2) focal hemiplegia in association with peduncular hemiplegia and paratonic rigiditydue due to compression of ipsilateral peduncle; 3) quick addition of vital disorders due to hemorrhagies into tectorium and it’s necrobiosis; 4) lethal outcome caused by herniation into occipital foramen due to necrobiosis of neurons in caudal part of brain stem tectorium.

Histamine H1 Receptor Contributes to Vestibular Compensation.

Vestibular compensation is responsible for the spontaneous recovery of postural, locomotor, and oculomotor dysfunctions in patients with peripheral vestibular lesion or posterior circulation stroke. Mechanism investigation of vestibular compensation is of great importance in both facilitating recovery of vestibular function and understanding the postlesion functional plasticity in the adult CNS. Here, we report that postsynaptic histamine H1 receptor contributes greatly to facilitating vestibular compensation. The expression of H1 receptor is restrictedly increased in the ipsilesional rather than contralesional GABAergic projection neurons in the medial vestibular nucleus (MVN), one of the most important centers for vestibular compensation, in unilateral labyrinthectomized male rats. Furthermore, H1 receptor mediates an asymmetric excitation of the commissural GABAergic but not glutamatergic neurons in the ipsilesional MVN, which may help to rebalance bilateral vestibular systems and promote vestibular compensation. Selective blockage of H1 receptor in the MVN significantly retards the recovery of both static and dynamic vestibular symptoms following unilateral labyrinthectomy, and remarkably attenuates the facilitation of betahistine, whose effect has traditionally been attributed to its antagonistic action on the presynaptic H3 receptor, on vestibular compensation. These results reveal a previously unknown role for histamine H1 receptor in vestibular compensation and amelioration of vestibular motor deficits, as well as an involvement of H1 receptor in potential therapeutic effects of betahistine. The findings provide not only a new insight into the postlesion neuronal circuit plasticity and functional recovery in the CNS, but also a novel potential therapeutic target for vestibular disorders.SIGNIFICANCE STATEMENT Vestibular disorders manifest postural imbalance, nystagmus, and vertigo. Vestibular compensation is critical for facilitating recovery from vestibular disorders, and of great importance in understanding the postlesion functional plasticity in the adult CNS. Here, we show that postsynaptic H1 receptor in the medial vestibular nucleus (MVN) contributes greatly to the recovery of both static and dynamic symptoms following unilateral vestibular lesion. H1 receptor selectively mediates the asymmetric activation of commissural inhibitory system in the ipsilesional MVN and actively promotes vestibular compensation. The findings provide not only a new insight into the postlesion neuronal circuit plasticity and functional recovery of CNS, but also a novel potential therapeutic target for promoting vestibular compensation and ameliorating vestibular disorders.

Abnormal Oculomotor Functions in Amyotrophic Lateral Sclerosis.

Background and PurposeAlthough traditionally regarded as spared, a range of oculomotor dysfunction has been recognized in amyotrophic lateral sclerosis (ALS) patients. ALS is nowadays considered as a neurodegenerative disorder of a third compartment comprising widespread areas of extra-motor brain including cerebellum. Our objective was to perform an observational study to examine for ocular motor dysfunction in patients with ALS and for any differences between bulbar-onset and spinal-onset patients.MethodsThirty two ALS patients (bulbar onset: 10, spinal onset: 22) underwent the standardized systemic evaluations using video-oculography.ResultsOculomotor dysfunctions such as square wave jerks, saccadic dysmetria, abnormal cogwheeling smooth pursuits and head shaking and positional nystagmus of central origin have been observed in the ALS patients at a relatively early stage. Abnormal smooth pursuits and saccadic dysmetria were increased in the bulbar-onset compared to the spinal-onset (p<0.05).ConclusionsThese oculomotor abnormalities may be a marker of neuro-degeneration beyond motor neurons in ALS, especially in bulbar-onset disease. Future longitudinal studies of eye movement abnormalities have provided insights into the distribution and nature of the disease process.

Clinical Heterogeneity of Anti-GM2-Ganglioside-Antibody Syndrome.

Background and PurposeAntiganglioside antibodies are known to play a pathogenic role in Guillain-Barré syndrome (GBS). Either an immunoglobulin (Ig)G- or IgM-type anti-GM2 antibody is detected in rare cases in GBS patients. However, the specific pathogenic role of these antibodies in GBS has not been reported previously. This study aimed to define and characterize the clinical spectrum of GBS with anti-GM2 positivity.MethodsWe reviewed the database of the Dong-A University Neuroimmunology Team, which has collected sera of GBS and its variants from more than 40 general and university-based hospitals in Korea. Detailed information about the involved patients was often obtained and then corrected by the charge doctor applying additional questionnaires.ResultsFour patients with acute monophasic peripheral neuropathy or cranial neuropathy with isolated IgM-type anti-GM2-antibody positivity were recruited. In addition, IgG-type anti-GM2 antibody was solely detected in the sera of another four patients. The IgM-positive group comprised heterogeneous syndromes: two cases of acute motor axonal neuropathy, one of acute inflammatory demyelinating polyneuropathy, and one of isolated facial diplegia. In contrast, all of the cases enrolled in the IgG-positive group manifested with dizziness with or without oculomotor palsy due to cranial neuropathy syndrome.ConclusionsThis study has identified that anti-GM2 antibody can be found in various subtypes of GBS and its variants in rare cases. Compared to the clinical heterogeneity of the IgM-positive group, the IgG-positive group can be characterized by cranial-dominant GBS variants presenting mainly with oculomotor and vestibular dysfunctions.