Nystagmus Research Articles

Comparative analysis of optotypes of Sivtsev, Golovin tables and infrared videonystagmography

Visiometry is one of the fundamental diagnostic methods for assessing visual acuity, including the evaluation of the effectiveness of eye pathology treatment. Therefore, a precise determination of visual acuity is crucial. For a long time, visual acuity has been determined by reading optotypes on optometric charts (in Russia and the CIS countries, the Sivtsev — Golovin chart is the most widely used). With the advancement of “Eye tracking” technologies and the development of high-frequency and detailed monitors, it has become possible to determine visual acuity using induction of normal physiological nystagmus, followed by an analysis and conclusion about the presence of nystagmus on specific presented optotypes. One of the key factors in the accuracy of visual acuity determination is the correct calculation of the size and movement of optotypes, which is analyzed in this review.

A novel mitochondrial DNA variant in MT-ND6: m.14430A>C p.(Trp82Gly) identified in a patient with Leigh syndrome and complex I deficiency

Leigh syndrome is a severe progressive mitochondrial disorder mainly affecting children under the age of 5 years. It is caused by pathogenic variants in any one of more than 75 known genes in the nuclear or mitochondrial genomes.A 19-week-old male infant presented with lactic acidosis and encephalopathy following a 2-week history of irritability, neuroregression and poor weight gain. He was hypotonic with pathological reflexes, impaired vision, and nystagmus. Brain MRI showed extensive bilateral symmetrical T2 hyperintense lesions in basal ganglia, thalami, and brainstem. Metabolic workup showed elevated serum alanine, and heavy lactic aciduria with increased ketones, fumarate, malate, and alpha-ketoglutarate as well as reduced succinate on urine organic acid analysis. Lactic acidemia persisted, with only a marginally elevated lactate:pyruvate ratio (16.46, ref. 0–10). He demised at age 7 months due to respiratory failure.Exome sequencing followed by virtual gene panel analysis for pyruvate metabolism and mitochondrial defects could not identify any nuclear cause for Leigh syndrome. Mitochondrial DNA (mtDNA) genome sequencing revealed 88% heteroplasmy for a novel variant, NC_012920.1(MT-ND6):m.14430A>C p.(Trp82Gly), in blood DNA. This variant was absent from the unaffected mother's blood, fibroblast, and urine DNA, and detected at a level of 5% in her muscle DNA.Mitochondrial respiratory chain analysis revealed markedly reduced mitochondrial complex I activity in patient fibroblasts (34% of parent and control cells), and reduced NADH-linked respirometry (less than half of parental and control cells), while complex II driven respirometry remained intact. The combined clinical, genetic, and biochemical findings suggest that the novel MT-ND6 variant is the likely cause of Leigh syndrome in this patient. The mitochondrial ND6 protein is a subunit of complex I.An interesting finding was the absence of a significantly elevated lactate:pyruvate ratio in the presence of severe lactatemia, which directed initial diagnostic efforts towards excluding a pyruvate metabolism defect. This case highlights the value of a multidisciplinary approach and complete genetic workup to diagnosing mitochondrial disorders in South African patients.

Effects of Baclofen on Central Paroxysmal Positional Downbeat Nystagmus

Paroxysmal positional nystagmus frequently occurs in lesions involving the cerebellum, and has been ascribed to disinhibition and enhanced canal signals during positioning due to cerebellar dysfunction. This study aims to elucidate the mechanism of central positional nystagmus (CPN) by determining the effects of baclofen on the intensity of paroxysmal positional downbeat nystagmus due to central lesions. Fifteen patients with paroxysmal downbeat CPN were subjected to manual straight head-hanging before administration of baclofen, while taking baclofen 30 mg per day for at least one week, and two weeks after discontinuation of baclofen. The maximum slow phase velocity (SPV) and time constant (TC) of the induced paroxysmal downbeat CPN were analyzed. The positional vertigo was evaluated using an 11-point numerical rating scale (0 to 10) in 9 patients. After treatment with baclofen, the median of the maximum SPV of paroxysmal downbeat CPN decreased from 30.1°/s [interquartile range (IQR) = 19.6—39.0°/s] to 15.2°/s (IQR = 11.2—22.0°/s, Wilcoxon signed rank test, p < 0.001) with the median decrement ratio at 40.2% (IQR = 28.2—50.6%). After discontinuation of baclofen, the maximum SPV re-increased to 24.6°/s (IQR = 13.1—34.4°/s, Wilcoxon signed rank test, p = 0.001) with the median increment ratio at 23.5% (IQR = 5.2—87.9%). In contrast, the TCs of paroxysmal downbeat CPN remained unchanged at approximately 3.0 s throughout the evaluation. The positional vertigo also decreased with the medication (Wilcoxon signed rank test, p = 0.020), and remained unchanged even after discontinuation of medication (Wilcoxon signed rank test, p = 0.737). The results of this study support the prior presumption that paroxysmal CPN is caused by enhanced responses of the semicircular canals during positioning due to cerebellar disinhibition. Baclofen may be tried in symptomatic patients with paroxysmal CPN.

Gravity-Dependent Modulation of Downbeat Nystagmus and Subjective Visual Vertical in the Roll Plane

Downbeat nystagmus (DBN) is the most common form of acquired central vestibular nystagmus. Gravity perception in patients with DBN has previously been investigated by means of subjective visual straight ahead (SVA) and subjective visual vertical (SVV) in the pitch and roll planes only during whole-body tilts. To our knowledge, the effect of head tilt in the roll plane on the SVV and on DBN has not yet been systematically studied in patients. In this study, we investigated static and dynamic graviceptive function in the roll-plane in patients with DBN (patients) and healthy-controls (controls) by assessment of the Subjective Visual Vertical (SVV) and the modulation of slow-phase-velocity (SPV) of DBN. SPV of DBN and SVV were tested at different head-on trunk-tilt positions in the roll-plane (0°,30° clockwise (cw) and 30° counterclockwise (ccw)) in 26 patients suffering from DBN and 13 controls. In patients, SPV of DBN did not show significant modulations at different head-tilt angles in the roll-plane. SVV ratings did not differ significantly between DBN patients vs. controls, however patients with DBN exhibited a higher variability in mean SVV estimates than controls. Our results show that the DBN does not exhibit any modulation in the roll-plane, in contrast to the pitch-plane. Furthermore, patients with DBN show a higher uncertainty in the perception of verticality in the roll-plane in form of a higher variability of responses.

Do Miniature Eye Movements Affect Neurofeedback Training Performance? A Combined EEG-Eye Tracking Study

EEG-based neurofeedback is a prominent method to modulate one’s own brain activity in a desired direction. However, the EEG signal can be disturbed by artifacts, e.g., eye movements, which can consequently confound the neurofeedback performance. Involuntary miniature eye movements can be hardly detected by conventional EEG correction methods such as recording the electro-oculogram (EOG) and subtracting EOG activity from the EEG signal. However, such miniature eye movements can influence EEG activity, especially in the Gamma frequency range, enormously. In the present study, we investigated whether power in different EEG frequencies can be effectively modulated by self-control of brain signals during neurofeedback training and/or whether changes in EEG power are provoked by miniature eye movements during the training. To this end, 24 participants performed one session of SMR and one session of Gamma neurofeedback training. Additionally, in each training session sham feedback was performed. An eye tracker was used to detect miniature eye movements (< 1°) during neurofeedback training. About two thirds of the participants were able to increase their SMR power over the course of NF training, while one third was able to increase Gamma power. Generally, miniature eye movements induced a strong Gamma power increase. The number of eye movements also increased numerically over the course of the NF training. However, we did not find a significant relationship with the NF training performance. This is a first indication that miniature saccades do not affect NF training performance, but should not be neglected during NF training. Our results have to be confirmed in future studies.

Microsaccades reflect attention shifts: a mini review of 20 years of microsaccade research.

Microsaccades are small, involuntary eye movements that occur during fixation. Since the 1950s, researchers have conducted extensive research on the role of microsaccades in visual information processing, and found that they also play an important role in human advanced visual cognitive activities. Research over the past 20 years further suggested that there is a close relationship between microsaccades and visual attention, yet lacking a timely review. The current article aims to provide a state-of-the-art review and bring microsaccades studies into the sight of attention research. We firstly introduce basic characteristics about microsaccades, then summarized the empirical evidence supporting the view that microsaccades can reflect both external (perception) and internal (working memory) attention shifts. We finally conclude and highlight three promising avenues for future research.

Cross-Modal Interactions Between Auditory Attention and Oculomotor Control.

Microsaccades are small, involuntary eye movements that occur during fixation. Their role is debated with recent hypotheses proposing a contribution to automatic scene sampling. Microsaccadic inhibition (MSI) refers to the abrupt suppression of microsaccades, typically evoked within 0.1 s after new stimulus onset. The functional significance and neural underpinnings of MSI are subjects of ongoing research. It has been suggested that MSI is a component of the brain's attentional re-orienting network which facilitates the allocation of attention to new environmental occurrences by reducing disruptions or shifts in gaze that could interfere with processing. The extent to which MSI is reflexive or influenced by top-down mechanisms remains debated. We developed a task that examines the impact of auditory top-down attention on MSI, allowing us to disentangle ocular dynamics from visual sensory processing. Participants (N = 24 and 27; both sexes) listened to two simultaneous streams of tones and were instructed to attend to one stream while detecting specific task "targets." We quantified MSI in response to occasional task-irrelevant events presented in both the attended and unattended streams (frequency steps in Experiment 1, omissions in Experiment 2). The results show that initial stages of MSI are not affected by auditory attention. However, later stages (∼0.25 s postevent onset), affecting the extent and duration of the inhibition, are enhanced for sounds in the attended stream compared to the unattended stream. These findings provide converging evidence for the reflexive nature of early MSI stages and robustly demonstrate the involvement of auditory attention in modulating the later stages.

Visual Field Deficits in Albinism in Comparison to Idiopathic Infantile Nystagmus.

This is the first systematic comparison of visual field (VF) deficits in people with albinism (PwA) and idiopathic infantile nystagmus (PwIIN) using static perimetry. We also compare best-corrected visual acuity (BCVA) and optical coherence tomography measures of the fovea, parafovea, and circumpapillary retinal nerve fiber layer in PwA. VF testing was performed on 62 PwA and 36 PwIIN using a Humphrey Field Analyzer (SITA FAST 24-2). Mean detection thresholds for each eye were calculated, along with quadrants and central measures. Retinal layers were manually segmented in the macular region. Mean detection thresholds were significantly lower than normative values for PwA (-3.10 ± 1.67 dB, P << 0.0001) and PwIIN (-1.70 ± 1.54 dB, P<0.0001). Mean detection thresholds were significantly lower in PwA compared to PwIIN (P<0.0001) and significantly worse for left compared to right eyes in PwA (P=0.0002) but not in PwIIN (P=0.37). In PwA, the superior nasal VF was significantly worse than other quadrants (P<0.05). PwIIN appeared to show a mild relative arcuate scotoma. In PwA, central detection thresholds were correlated with foveal changes in the inner and outer retina. VF was strongly correlated to BCVA in both groups. Clear peripheral and central VF deficits exist in PwA and PwIIN, and static VF results need to be interpreted with caution clinically. Since PwA exhibit considerably lower detection thresholds compared to PwIIN, VF defects are unlikely to be due to nystagmus in PwA. In addition to horizontal VF asymmetry, PwA exhibit both vertical and interocular asymmetries, which needs further exploration.

The First 100 Children Treated in a Newly Established Pediatric Vertigo Center.

Correctly diagnosing dizziness in children is essential for appropriate management; nevertheless, healthcare professionals face challenges due to children's limited ability to describe their symptoms and their cooperation during physical examination. The objective of this study is to describe the first 100 patients seen at a newly established pediatric vertigo center. This is a retrospective review of a consecutive series of 100 patients seen at our pediatric vertigo clinic in a tertiary referral center from August 2019 until June 2022. Comprehensive clinical data were collected. The diagnoses were established by 2 pediatric otolaryngologists based on validated diagnostic criteria. Trends in diagnosis, investigation, and treatment of these patients were analyzed. A total of 100 children were included in the study. Vestibular migraine was the most common diagnosis (20%) followed by benign paroxysmal vertigo of childhood (14%). Eleven patients had combined pathologies. Fifteen out of 70 children (21%) had abnormal audiograms, 30 out of 48 children (62.5%) had abnormal vestibular testing, and 6 out of 31 (19%) patients had abnormal imaging. Fifty-one children received medical treatment, 23 received vestibular physiotherapy, and 9 patients had particle repositioning maneuvers; moreover, 17 of these patients received multimodal treatment. Our analysis suggests that imaging and audiology testing have relatively low yield in the assessment of pediatric vertigo. On the other hand, vestibular testing detected a high proportion of abnormalities, such as saccadic pursuit, vertical nystagmus, central positional nystagmus, and abnormal directional preponderance, particularly associated with vestibular migraine. Given the complexity of diagnosing vertigo in children, it is critical to establish multidisciplinary specialized centers capable of providing accurate diagnosis and treatment for these children.

Truncated FRMD7 proteins in congenital Nystagmus: novel frameshift mutations and proteasomal pathway implications

Idiopathic congenital nystagmus (ICN) manifests as involuntary and periodic eye movements. To identify the genetic defect associated with X-linked ICN, Whole Exome Sequencing (WES) was conducted in two affected families. We identified two frameshift mutations in FRMD7, c.1492dupT/p.(Y498Lfs*15) and c.1616delG/p.(R539Kfs*2). Plasmids harboring the mutated genes and qPCR analysis revealed mRNA stability, evading degradation via the NMD pathway, and corroborated truncated protein production via Western-blot analysis. Notably, both truncated proteins were degraded through the proteasomal (ubiquitination) pathway, suggesting potential therapeutic avenues targeting this pathway for similar mutations. Moreover, we conducted a comprehensive analysis, summarizing 140 mutations within the FRMD7 gene. Our findings highlight the FERM and FA structural domains as mutation-prone regions. Interestingly, exons 9 and 12 are the most mutated regions, but 90% (28/31) mutations in exon 9 are missense while 84% (21/25) mutations in exon 12 are frameshift. A predominant occurrence of shift code mutations was observed in exons 11 and 12, possibly associated with the localization of premature termination codons (PTCs), leading to the generation of deleterious truncated proteins. Additionally, our conjecture suggests that the loss of FRMD7 protein function might not solely drive pathology; rather, the emergence of aberrant protein function could be pivotal in nystagmus etiology. We propose a dependence of FRMD7 protein normal function primarily on its anterior domain. Future investigations are warranted to validate this hypothesis.

Oculomotor inhibition markers of working memory load.

Involuntary eye movements occur constantly even during fixation and were shown to convey information about cognitive processes. They are inhibited momentarily in response to external stimuli (oculomotor inhibition, OMI), with a time and magnitude that depend on stimulus saliency, attention, and expectations. It was recently shown that the working memory load for numbers modulates the microsaccade rate; however, the generality of the effect and its temporal properties remain unclear. Our goal was to investigate the relationship between OMI and the working memory load for simple colored shapes. Participants (N = 26) maintained their fixation while their eyes were tracked; they viewed briefly flashed colored shapes accompanied by small arrows indicating the shapes to be memorized (1/2/3). After a retention period, a probe shape appeared for matching. The microsaccade rate modulation and temporal properties were analyzed for the memory encoding, maintenance, and retrieval phases. Microsaccade inhibition was stronger when more shapes were memorized, and performance improved when microsaccades were suppressed during maintenance and retrieval. This occurred even though the physical stimuli were identical in number under all conditions. Thus, oculomotor inhibition may play a role in silencing the visual input while processing current stimuli and is generally related to processing time and load.

Nystagmus in the B6(CG)Tyr(c-2J)/J Albino Mouse: A Functional and RNA-Seq Analysis.

Infantile nystagmus syndrome (INS) is a gaze-holding disorder characterized by conjugate, uncontrolled eye oscillations that can result in significant visual acuity loss. INS is often associated with albinism, but the mechanism is unclear. Albino mice have nystagmus; however, a pigmented mouse with a tyr mutation making it phenotypically albino, the B6(CG)-Tyr(c-2J)/J (B6 albino), had not been tested. We tested optokinetic response (OKR) in B6 albino and control mice. RNA-Seq was performed on extraocular muscles (EOM), tibialis anterior (TA) muscle, abducens (CN6), and oculomotor (CN3) neurons to uncover molecular differences that may contribute to nystagmus. OKR was measured using an ISCAN system. RNA was isolated from four tissues to identify differentially expressed genes and validated with qPCR and immunohistochemistry. Ingenuity pathway analyses identified top biological pathways. All B6 albino mice tested had nystagmus. Differential RNA expression analysis showed 383 genes differentially expressed in EOM, 70 in CN3, 20 in CN6, and 639 in the TA. Two genes were differentially expressed in all four tissues: wdfy1 and nnt. Differences were validated by qPCR and immunostaining. The tyr mutation in B6 albino mice, genotypically pigmented and phenotypically albino, is sufficient to result in spontaneous nystagmus. The two genes with decreased expression in the B6 albino tissues examined, wdfy1 and nnt, have been implicated in mitochondrial dysfunction and stem cell maintenance in other systems. Their function in extraocular muscle is unknown. These studies suggest that this mouse model of nystagmus may allow molecular identification of candidate nystagmus-related genes.

Update on central oculomotor disorders and nystagmus

The diagnosis of ocular motor disorders and the different forms of a nystagmus is based on a systematic clinical examination of all types of eye movements: eye position, spontaneous nystagmus, range of eye movements, smooth pursuit, saccades, gaze-holding function, vergence, optokinetic nystagmus, as well as testing of the function of the vestibulo-ocular reflex (VOR) and visual fixation suppression of the VOR. Relevant anatomical structures are the midbrain, pons, medulla, cerebellum, and cortex. There is a simple clinical rule: vertical and torsional eye movements are generated in the midbrain, horizontal in the pons. The cerebellum is relevant for almost all types of eye movements; typical pathological findings are saccadic smooth pursuit, gaze-evoked nystagmus or dysmetric saccades.Nystagmus is defined as a rhythmic, most often involuntary eye movement. It normally consists of a slow (pathological) drift of the eyes and a fast central compensatory movement of the eyes back to the primary position (re-fixation saccade). There are three major categories: first, spontaneous nystagmus, i. e. nystagmus which occurs in the gaze straight ahead position as upbeat or downbeat nystagmus; second, nystagmus that becomes visible at eccentric gaze only and third, nystagmus which can be elicited by certain maneuvers, e. g. head-shaking, head positioning, air pressure or hyperventilation, most of which are of peripheral vestibular origin. The most frequent central types of spontaneous nystagmus are downbeat and upbeat, infantile, pure torsional, pendular fixation, periodic alternating, and seesaw nystagmus. Many types of central nystagmus allow a precise neuroanatomical localization: for instance, downbeat nystagmus, which is most often caused by a bilateral floccular lesion or dysfunction, or upbeat nystagmus, which is caused by a lesion in the mesencephalon or medulla oblongata. Examples of pharmacotherapy are the use of 4-aminopyridine for downbeat and upbeat nystagmus, memantine or gabapentin for fixation pendular nystagmus or baclofen for periodic alternating nystagmus.

Occupational Health Hazards among Petrol Station Workers in Ibadan, Oyo State, Nigeria

When a consumer comes to the gas station to buy fuel, the attendants are their initial point of contact. Petrol station employees deal with a variety of risks and health issues on the job. This study was carried out to ascertain the health risks, occupational safety practices, and health issues among gas station workers in Ibadan, Oyo State. Africa.&#x0D; This intervention study was conducted with all willing attendants that operate at Ibadan's filling stations. A semi-structured interviewer-administered English-language questionnaire was used to gather data. STATA 12.1 software was used for data analysis after structured interviewer-administered questionnaires were used to gather data. Both descriptive and inferential statistics were used in the analysis. A 5% threshold for significance was used.&#x0D; The study involved 620 respondents in total for both genders, the mean age of the responders was 29.4 ± 4.6 years. The inhalation of petrol fumes, customer confrontation, and noise exposure were among the hazards that were reported. Dust-related chronic cough; heat stress that frequently leads to heat exhaustion and heat stroke; hearing loss; hypertension from excessive equipment noise; back and general body ache from bending over repeatedly at work; robbery; fire; harsh weather; and exhaust fume incidence. Health problems reported included headache, blurry vision, vomiting, drowsiness, vertigo, heartburn, slurred speech, weakness, staggering, facial flushing, itching, loss of consciousness, heart failure, convulsion, irritability, memory loss, nausea, tremor, involuntary eye movement, cough, muscle spasms, hallucination, altered vision, insomnia, poor appetite and stomach upset factor associated with health problem. The results, which have a p-value of 0.29, demonstrate that there is no meaningful correlation between occupational safety practices and health issues. Occupation-related health hazards, work environment, and health problems are significantly correlated, with p-values of less than 0.01. Additionally, there is no significant correlation (p-value of 0.12), between understanding of safety procedures and health issues.&#x0D; In conclusion, the study found that attendants at fiilling stations were subjected to a variety of risks and health issues. Poor hand washing techniques, first aid box availability, PPE awareness and use, and medical assessment procedures were all present. The Independent Petroleum Marketers Association and other relevant parties should endeavor to guarantee that filling station owners assume accountability for the well-being and security of their employees.

10249-PEDT-8 CURRENT STATUS AND ISSUES OF PEDIATRIC DIFFUSE INTRINSIC PONTINE GLIOMA (DIPG)

Abstract that predominantly occurs in childhood, with a median survival of less than one year. Herein we present a recent case of DIPG and discuss the current status and future challenges. The patient was a 7-year-old boy who complained of tinnitus, headaches, and unstable gait. The MRI showed diffuse enlargement of the pons, and the contrast-enhanced T1-weighted image exhibited an irregular ring-like enhancement. Neurologically, he presented with left abducens nerve palsy, horizontal gaze nystagmus, significant left ataxia, and truncal ataxia. As the lesion extended to the left cerebellar peduncle, a stereotactic biopsy was performed. However, postoperative bleeding occurred, resulting in transient consciousness disturbance, left facial palsy, speech disturbance, and dysphagia, necessitating enteral nutrition management. The pathological diagnosis was high-grade glioma, IDH wild type, H3K27M mutation (-), TERTp wild type, BRAF V600E mutation (-), BRAF fusion (-), and MGMT unmethylated. After surgery, the patient received radiation therapy (54Gy/30fr), and his symptoms improved, allowing him to resume oral intake. Post-irradiation, the lesion shrank, and he was discharged home without assistance. However, six months later, his symptoms worsened, and he started taking temozolomide orally, but the effect was limited. Nine months later, he became unable to take oral medication, and a central venous port was placed. We coordinated with home care physicians to provide intravenous and palliative treatments, but respiratory and consciousness disturbances gradually worsened, and he died 10 months after the initial diagnosis. The median survival of DIPG patients treated at our hospital is currently 10.5 months, and this case followed a typical course. The development of novel treatments is desired, but due to the rarity of the disease, conducting comparative trials is challenging. Hence, registry data forming a control group are necessary. Additionally, transitioning to home-based palliative care and sharing information on supportive therapies are also critical tasks.

Opsoclonus-Myoclonus Syndrome and Acquired Von Willebrand Syndrome As Manifestations of Graft-Versus-Host Disease

Background: Opsoclonus-myoclonus syndrome (OMS), known as dancing eye syndrome, is a rare neurological disorder characterised by a triad of opsoclonus (rapid, involuntary eye movements), myoclonus (uncontrolled muscle twitches) and ataxia. The syndrome is usually seen in children, often associated with neuroblastoma, and is extremely rare in adults. The pathogenesis is thought to be immune in nature and aetiology is variable although most cases are associated with solid tumors or after an infection. Treatment involves a combination of managing the underlying condition and immunosuppression. Acquired von Willebrand disease is a rare acquired bleeding disorder with a range of different aetiologies including lymphoproliferative, myeloproliferative, cardiovascular and autoimmune disorders. The pathogenic mechanism, in most cases is due to increased plasma clearance of von Willebrand factor (vWF) caused by such mechanisms as antibodies, cell adsorption, shear stress or increased proteolysis. Therapeutic approaches focus on prevention of bleeding through supportive treatment, and management of the underlying cause. To the best of our knowledge, this is the first case of opsoclonus-myoclonus syndrome with concurrent acquired von Willebrand disease as manifestations of graft versus host disease. Case: Here we present the case of a 47-year-old man presenting with opsoclonus myoclonus syndrome and concurrent acquired von Willebrand disease as manifestations of graft versus host disease. The patient had a background of relapsed myeloid sarcoma after haploidentical allogeneic haematopoietic stem cell transplant with subsequent chemotherapy to achieve full remission. He received donor lymphocyte infusion as consolidation therapy to enhance the graft-versus leukaemia effect. Six weeks following donor T cell infusion of 1 x 10^6 CD3 cells/kg, he presented with initial features suggestive of graft versus host disease (GVHD) of the digestive tract and subsequently developed neurological manifestations in the form of rapid, repetitive, involuntary and multidirectional eye movements; tremors and ataxia. Further tests prior to planned invasive testing revealed an additional new diagnosis of acquired von Willebrand disease, requiring supportive von Willebrand factor concentrate infusion. Multiple extensive investigations including cerebral MRI imaging, cerebrospinal fluid analysis and paraneoplastic antibodies were all negative for associated malignancy, infection, other autoimmune disorder or disease relapse. Skin, bone marrow examination and cross-sectional imaging confirmed complete remission with complete donor chimerism in all blood cell lineages. The patient commenced steroid immunosuppression for treatment of gastrointestinal GVHD with complete resolution of all symptoms and clinical parameters. Conclusion: We highlight a rare case of central nervous system involvement with graft versus host disease following cellular therapy, manifesting as the rare opsoclonus-myoclonus syndrome with associated acquired von Willebrand disease. The proposed pathological mechanism is the activation of host tissue antigen-specific T and B cells, resulting in autoantibody and cytokine-mediated effects upon neuronal tissue and coagulation proteins. Use of glucocorticoids in this case to suppress auto-antibody formation, block transcription of pro-inflammatory genes and induce lymphocyte depletion was rapidly effective and provided durable remission of symptoms, without recurrence on cessation of immunosuppression. This case highlights the need for close clinical and biochemical monitoring of patients during the risk period following allogeneic cellular therapy, for serious allo-immune manifestations not fitting classical descriptions of GVHD.

Central positional nystagmus due to acute medial medullary infarction

A 70-year-old male with risk factors for vascular disease presented with dizziness and instability. The patient showed horizontal geotropic nystagmus when turning his head while lying down, with larger slow phase velocity observed when turning to the left. There were no other neurological deficits. Video head impulse tests and vestibular evoked myogenic potentials were normal. The initial magnetic resonance imaging (MRI) findings were negative; however, the patient experienced subsequent right-side weakness, right tilting, and recurrent episodes of vertigo. A follow-up MRI revealed an acute left medial medullary infarction, which seems to have caused the paroxysmal geotropic central positional nystagmus in this patient.

Seizure as the first symptom of cavernous sinus dural arteriovenous fistula: A case report and literature review

Cavernous sinus dural arteriovenous fistula (CS-DAVF) is an abnormal arteriovenous communication associated with a variety of clinical manifestations. The previous literature has rarely reported the occurrence of CS-DAVF with seizures and cerebral hemorrhage, signaling the need for more case reports and literature review in this area. A 62-year-old Chinese female presented with a paroxysmal loss of consciousness, accompanied with involuntary eye movement to the left, chewing issues, salivation at the right corner of the mouth, and bit tongue. The brain computed tomography revealed that the left temporal lobe was hemorrhagic. Brain scan and contrast-enhanced magnetic resonance imaging showed diffuse meningeal enhancement and lesions in the left frontoparietal temporal lobe, insular lobe, and hippocampal head region. Electroencephalography demonstrated continuous emission of spike and slow waves in the left hemisphere. With the aid of digital subtraction angiography, the patient was confirmed with a diagnosis of CS-DAVF draining into the ipsilateral cavernous sinus, intercavernous sinus, contralateral cavernous sinus, left superior ophthalmic vein, left lateral fissure vein, and left pterygoid venous plexus. The fistula was closed with interventional embolization through the femoral vein, and immediate angiography showed complete resolution of CS-DAVF after operation. The patient did not manifest any post-operative complications. This case highlights that the prevention of epilepsy, cerebral hemorrhage, and other serious complications is extremely important for good prognosis, especially in some patients presenting with serious clinical symptoms. It also sheds light on the necessity to consider the diagnosis of CS-DAVF if seizures, although extremely rare, are present.

Pre-occupancy evaluation of a virtual music school classroom: Influence of color and type of lighting on music performers

The built environment has the potential to influence human emotions, behaviors, and cognitive abilities. This study examined the influence of classroom architectural design variables on musicians’ emotional and cognitive experiences during solo performance. Specifically, the effects of color and type of lighting were explored. Using immersive virtual reality technology, musicians were immersed in a virtual representation of a real conservatory classroom. Study participants were exposed to variations in room design while playing their instruments. Questionnaires were used to assess the musicians’ level of immersion in the virtual environment and to determine how design variables affected their perception of the environment and emotional state. In addition, eye tracking was used to record eye behavior during performance and to identify involuntary eye movements indicative of emotional arousal. The results of this study support the feasibility of enhancing the musician experience and reducing performance anxiety during solo performances by manipulating environmental design variables. Our research showed that the combination of daylight and window views contributed significantly to a more positive evaluation of the environment, making it appear more pleasant, open, warm and light. In contrast, the absence of daylight and no outside views not only had a negative impact on environmental ratings, but also significantly increased saccadic eye movements, which are associated with higher levels of anxiety. In addition, rooms with reddish walls and floors were perceived as warmer than those with blue or gray tones.

Visual search in infantile nystagmus syndrome

ABSTRACT Clinical relevance Research on infantile nystagmus syndrome (INS) and visual search is limited. Conducting this research could assist practitioners in understanding how INS affects the real-life visual activities of patients and aid in developing new clinical visual function assessments for INS. Background The aim of this work is to investigate how subjects with INS perform visual search tasks, and, particularly, to assess how INS subjects perform when targets are located at their null position or away from it, and when under additional cognitive demands. Methods INS subjects (N = 15) and controls (N = 20) performed conjunction and feature search tasks, both with and without mental arithmetic. Search performance was assessed using log-transformed total search time, gaze-dependent search time, and accuracy. Cognitive demand was quantified by pupil size and the NASA task-load index score. Results INS subjects showed longer search times compared to controls in conjunction search (P < 0.01), but not in feature search. Within INS and control subjects, the total search times were significantly increased by the addition of mental arithmetic (P < 0.0001). There was no difference in gaze-dependent search times between null target position and 15° away from null target position of subjects in conjunction search (P > 0.05). Accuracies were 100% for both control and INS subjects in both conjunction and feature search. Conclusion Conjunction visual search was impaired in adult INS subjects, and further worsened under increased cognitive demand. The null position did not affect the visual search performance in INS