Sudden hearing loss as the initial symptom in Japanese patients with multiple sclerosis and seropositive neuromyelitis optica spectrum disorders

Neuromyelitis optica spectrum disorder: Exploring the diverse clinical manifestations and the need for further exploration

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disorder characterized by inflammatory assaults on the central nervous system (CNS), particularly on the optic nerves and spinal cord. In recent years, a wider range of clinical manifestations of this complex disease have been observed, emphasizing the importance of gaining a more profound understanding beyond optic neuritis (ON) and transverse myelitis (TM).

CURRENT KNOWLEDGE

This study explores the many clinical symptoms of NMOSD, including common and uncommon presentations. Distinctive aspects of ON, TM, and diencephalic/brainstem syndromes are examined, highlighting their unique characteristics in contrast to conditions such as multiple sclerosis. We also discuss extra-CNS involvement, such as unusual signs, including muscle involvement, retinal injury, auditory impairment, and rhinological symptoms.

AIMS AND OBJECTIVES

Our study intends to highlight the wide range and complexity of NMOSD presentations, emphasizing the significance of identifying unusual symptoms for precise diagnosis and prompt management. The specific processes that contribute to the varied clinical presentation of NMOSD are not well understood despite existing information. This emphasizes the necessity for more study to clarify the mechanisms that cause different symptoms and discover new treatment targets for this complex autoimmune disorder.

CONCLUSION

It is essential to acknowledge the complex and varied clinical manifestations of NMOSD to enhance diagnosis, treatment, and patient results. By enhancing our comprehension of the fundamental processes and investigating innovative therapeutic approaches, we may aim to enhance the quality of life for persons impacted by this illness.

Role of Inner Ear Macrophages and Autoimmune/Autoinflammatory Mechanisms in the Pathophysiology of Inner Ear Disease

Macrophages play important roles in tissue homeostasis and inflammation. Recent studies have revealed that macrophages are dispersed in the inner ear and may play essential roles in eliciting an immune response. Autoinflammatory diseases comprise a family of immune-mediated diseases, some of which involve sensorineural hearing loss, indicating that similar mechanisms may underlie the pathogenesis of immune-mediated hearing loss. Autoimmune inner ear disease (AIED) is an idiopathic disorder characterized by unexpected hearing loss. Tissue macrophages in the inner ear represent a potential target for modulation of the local immune response in patients with AIED/autoinflammatory diseases. In this review, we describe the relationship between cochlear macrophages and the pathophysiology of AIED/autoinflammatory disease.

High level of IgE in acute low-tone sensorineural hearing loss: A predictor for recurrence and Meniere Disease transformation

BACKGROUND

Autoimmunity may play an important role in sudden onset sensorineural hearing loss. However, little is known about the relationship between immunoglobulin E (IgE) and acute low-tone sensorinerual hearing loss (ALHL).

OBJECTIVES

To investigate the relationship between IgE level and endolymphatic hydrops and outcomes of ALHL.

METHODS

A total of 242 subjects with sudden onset hearing loss, including 115 with ALHL and 127 with idiopathic sudden sensorineural hearing loss (ISSHL), were included in this study. Peripheral venous blood samples of 242 subjects were collected for detection. Clinical data, IgE level, and distribution of allergens were compared between the ALHL and ISSHL groups. The ALHL group received an electrocochleogram (ECochG) test and a follow-up in the outpatient unit or by telephone to evaluate outcomes.

RESULTS

Compared to the values in the ISSHL group, a significantly younger onset age (42.30±14.33 years old), higher female onset proportion (72/115, 62.61%), increased total IgE level (median: 66.47, interquartile range: 24.56, 180.96, IU/mL) and specific IgE level (median: 9.42, interquartile range: 1.42, 22.23 IU/mL) were noted in the ALHL group. A clear difference in allergen distribution was noted between the ALHL and ISSHL groups (p=.001). Total IgE and specific IgE levels were factors that contributed to the SP/AP ratio in the electrocochleogram (ECochG) (R²=0.413) in ALHL group. Finally, during the follow-up (17.61±3.46 months) for the ALHL group, 37 subjects recurred, and 17 subjects developed Meniere Disease. In the ROC curve for ALHL recurrence, the area under the curve (AUC) of total IgE was 0.709 and that of specific IgE was 0.679. For MD transformation, the AUC of total IgE was 0.736 and that of specific IgE was 0.716.

CONCLUSIONS

High IgE levels correlated with an enhanced SP/AP ratio in ALHL. High IgE levels could be used as a predictor of ALHL recurrence and MD transformation.

Neuromyelitis optica spectrum disorder with deafness and an extensive brainstem lesion

A 49-year-old woman developed vomiting, hiccups, double vision, and bilateral ptosis, after which tinnitus and deafness appeared. Head magnetic resonance imaging (MRI) showed a brainstem lesion focused on the midbrain and pons. Anti-aquaporin 4 (AQP4) antibody was positive, and there was no evidence of optic neuritis or myelitis, leading to the diagnosis of neuromyelitis optica spectrum disorder (NMOSD). The auditory brainstem response (ABR) showed no derivation of wave V on left stimulation and extended latency between waves III and V on right stimulation, so impairment between the midbrain and pons was suspected. It was useful to evaluate head MRI and the ABR for identification of the location of auditory pathway dysfunction.

Auditory impairment in H-ABC tubulinopathy

Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) is a neurodegenerative disease due to mutations in TUBB4A. Patients suffer from extrapyramidal movements, spasticity, ataxia, and cognitive deficits. Magnetic resonance imaging features are hypomyelination and atrophy of the striatum and cerebellum. A correlation between the mutations and their cellular, tissue and organic effects is largely missing. The effects of these mutations on sensory functions have not been described so far. We have previously reported a rat carrying a TUBB4A (A302T) mutation and sharing most of the clinical and radiological signs with H-ABC patients. Here, for the first time, we did a comparative study of the hearing function in an H-ABC patient and in this mutant model. By analyzing hearing function, we found that there are no significant differences in the auditory brainstem response (ABR) thresholds between mutant rats and WT controls. Nevertheless, ABRs show longer latencies in central waves (II-IV) that in some cases disappear when compared to WT. The patient also shows abnormal AEPs presenting only Waves I and II. Distortion product of otoacoustic emissions and immunohistochemistry in the rat show that the peripheral hearing function and morphology of the organ of Corti are normal. We conclude that the tubulin mutation severely impairs the central hearing pathway most probably by progressive central white matter degeneration. Hearing function might be affected in a significant fraction of patients with H-ABC; therefore, screening for auditory function should be done on patients with tubulinopathies to evaluate hearing support therapies.

Acute vestibular syndrome and hearing loss mimicking labyrinthitis as initial presentation of multiple sclerosis

Acute vestibular syndrome is most often caused by vestibular neuritis or stroke, although demyelinating diseases may be responsible for 4% of all AVS episodes. The authors present the case of a previously healthy 17-year-old female patient complaining of spontaneous vertigo and right-sided hearing loss. Otoneurological examination suggested a peripheral vestibular cause and video head impulse test revealed a reduced vestibulo-ocular reflex gain. The presence of sensorineural hearing loss raised the suspicion of a central cause and prompted imaging evaluation. A brain MRI evidenced demyelinating lesions in the right middle cerebellar peduncle and the patient was ultimately diagnosed with Multiple Sclerosis.

Case series: Hearing loss in neuromyelitis optica spectrum disorders

BACKGROUND

Aquaporin 4 (AQP4)- and myelin oligodendrocyte glycoprotein (MOG)-associated neuromyelitis optica spectrum disorders (NMOSD) are thought to primarily affect the central nervous system (CNS). However, emerging evidence suggests that there are extra-CNS manifestations of NMOSD, including myopathies, gastrointestinal dysfunction, renal involvement and adverse pregnancy outcomes.¹ METHODS: Three patients who reported hearing loss during a NMOSD relapse were identified through a retrospective case review.

RESULTS

In this article, we discuss two AQP4-IgG positive NMOSD cases, each presenting with conductive and sensorineural hearing loss, and a case of MOG-IgG-associated NMOSD presenting with sensorineural hearing loss.

CONCLUSION

Hearing loss may be present as a relapse in patients with NMOSD. Early recognition and timely treatment are essential to prevent irreversible hearing loss.

Effectiveness of Steroid Treatment for Sudden Sensorineural Hearing Loss: A Meta-analysis of Randomized Controlled Trials

Background:

The best way to administer steroids for sudden sensorineural hearing loss (SSHL) is still unclear. The present study was aimed at estimating the efficacy of steroids by intratympanic, systemic, and combined therapy (CT) routes.

Methods:

A systematic literature search was performed from 1950 to October 2019 for randomized controlled trials comparing the use of intratympanic, systemic, and combined steroid therapy for SSHL. The outcomes of recovery rate and pure tone average (PTA) improvement were assessed by random-effects and fixed-effects meta-analysis.

Results:

A total of 20 articles identified from 7 countries were eligible for analysis. Although no significant difference in recovery rate was observed between intratympanic steroid therapy (IST) and systemic steroid therapy (SST), IST did demonstrate better hearing improvement, as evidenced by a higher PTA than SST. Compared with SST, CT comprising IST and SST had significant recovery rate improvement. Patients treated with CT had a significantly higher PTA than those treated with SST. Through subgroup analysis based on the equivalent dose of prednisone, it was shown that CT led to a significantly higher PTA than SST only in the high-dose CT versus high-dose SST groups and moderate-dose CT versus high-dose SST groups.

Conclusion:

Moderate and high dose of CT could accelerate hearing improvement in SSHL.

High Risk of Sudden Sensorineural Hearing Loss in Several Autoimmune Diseases according to a Population-Based National Sample Cohort Study

OBJECTIVE

We investigated the risk of sudden sensorineural hearing loss (SSNHL) in patients with autoimmune diseases compared with a control group in a population-based study using a National Health Insurance Service National Sample Cohort data from Korea.

METHODS

We enrolled autoimmune-disease patients who were ≥20 years of age in 2006 into the autoimmune-disease group, and selected a control group with similar demographic characteristics. We tracked the 2 groups from 2006 to 2015 and compared the proportions of patients who developed SSNHL.

RESULTS

Of 13,250 patients in the autoimmune-disease group, 145 experienced an SSNHL event (1.09%). Of the 66,250 in the control group, 484 experienced an SSNHL event (0.73%). The SSNHL risk was significantly higher in the autoimmune-disease group than in the control group. SSNHL incidence was significantly higher among patients with antiphospholipid syndrome (APS), multiple sclerosis (MS), rheumatoid arthritis (RA), and connective-tissue diseases including Sjögren syndrome and Behçet disease. In detailed stratified analyses using reinforced additional diagnostic codes, only RA patients had a significantly higher SSNHL incidence than the control group.

CONCLUSION

The association of several autoimmune diseases with SSNHL was evaluated in this large-scale, population-based, big-data study. The risk of SSNHL was significantly higher in patients with APS, MS, RA, and connective-tissue diseases including Sjögren syndrome and Behçet disease than in patients without autoimmune diseases. SSNHL, in particular, was significantly associated with RA according to detailed analyses using reinforced additional diagnostic codes.

Comprehensive review of neuromyelitis optica and clinical characteristics of neuromyelitis optica patients in Puerto Rico

Neuromyelitis optica (NMO) is an immune-mediated inflammatory disorder of the central nervous system. It is characterized by concurrent inflammation and demyelination of the optic nerve (optic neuritis [ON]) and the spinal cord (myelitis). Multiple studies show variations in prevalence, clinical, and demographic features of NMO among different populations. In addition, ethnicity and race are known as important factors on disease phenotype and clinical outcomes. There are little data on information about NMO patients in underserved groups, including Puerto Rico (PR). In this research, we will provide a comprehensive overview of all aspects of NMO, including epidemiology, environmental risk factors, genetic factors, molecular mechanism, symptoms, comorbidities and clinical differentiation, diagnosis, treatment, its management, and prognosis. We will also evaluate the demographic features and clinical phenotype of NMO patients in PR. This will provide a better understanding of NMO and establish a basis of knowledge that can be used to improve care. Furthermore, this type of population-based study can distinguish the clinical features variation among NMO patients and will provide insight into the potential mechanisms that cause these variations.

Screening of genes associated with inflammatory responses in the endolymphatic sac reveals underlying mechanisms for autoimmune inner ear diseases

The current study analyzed gene expression profiles of the endolymphatic sac (ES) in rats and identified expressed genes, present in the human and rat ES, to reveal key hubs for inflammatory responses. Microarray data (accession no. E-MEXP-3022) were obtained from the European Bioinformatics Institute database, including three biological replicates of ES plus dura tissues and three replicates of pure dura tissues form rats. Differentially expressed genes (DEGs) were screened using the Linear Model for Microarray data method and a protein-protein interaction (PPI) network was constructed using data from the Search Tool for the Retrieval of Interacting Genes/Proteins database followed by a module analysis via Clustering with Overlapping Neighborhood Expansion. Function enrichment analysis was performed using the Database for Annotation, Visualization and Integrated Discovery online tool. A total of 612 DEGs were identified, including 396 upregulated and 216 downregulated genes. Gene ontology term enrichment analysis indicated DEGs were associated with cell adhesion, including α5-integrin (Itga1) and secreted phosphoprotein 1 (Spp1); T cell co-stimulation, including C-C chemokine ligand (Ccl)21 and Ccl19; and the toll-like receptor signaling pathway, including toll-like receptor (Tlr)2, Tlr7 and Tlr8. These conclusions were supported by Kyoto Encyclopedia of Genes and Genomes pathway analyses revealing extracellular matrix-receptor interaction, including Itga1 and Spp1; leukocyte transendothelial migration, includingclaudin-4 (Cldn4); and malaria, including Tlr2. The hub roles of Itga1, Cd24 and Spp1 were revealed by calculating three topological properties of the PPI network. Ccl21, Ccl19 and Cldn4 were demonstrated to be crucial following significant module analysis according to the corresponding threshold, which revealed they were enriched in inflammation pathways. Tlr7, Tlr2, granzyme m and Tlr8 were common genes associated with inflammatory responses in rat and human ES. In conclusion, abnormal expression of the aforementioned inflammation-associated genes may be associated with the development of autoimmune inner ear diseases.

Impairment of frequency-specific responses associated with altered electrical activity patterns in auditory thalamus following focal and general demyelination

Multiple sclerosis is characterized by intermingled episodes of de- and remyelination and the occurrence of white- and grey-matter damage. To mimic the randomly distributed pathophysiological brain lesions observed in MS, we assessed the impact of focal white and grey matter demyelination on thalamic function by directing targeted lysolecithin-induced lesions to the capsula interna (CI), the auditory cortex (A1), or the ventral medial geniculate nucleus (vMGN) in mice. Pathophysiological consequences were compared with those of cuprizone treatment at different stages of demyelination and remyelination. Combining single unit recordings and auditory stimulation in freely behaving mice revealed changes in auditory response profile and electrical activity pattern in the thalamus, depending on the region of the initial insult and the state of remyelination. Cuprizone-induced general demyelination significantly diminished vMGN neuronal activity and frequency-specific responses. Targeted lysolecithin-induced lesions directed either to A1 or to vMGN revealed a permanent impairment of frequency-specific responses, an increase in latency of auditory responses and a reduction in occurrence of burst firing in vMGN neurons. These findings indicate that demyelination of grey matter areas in the thalamocortical system permanently affects vMGN frequency specificity and the prevalence of bursting in the auditory thalamus.

The Role of Autoimmunity in the Pathogenesis of Sudden Sensorineural Hearing Loss

Sudden sensorineural hearing loss (SSHL) is a clinically common acute symptom in otolaryngology. Although the incidence of SSHL has increased around the world in recent years, the etiology of the disease is still unclear. It has been reported that infections, ototoxic drugs, membrane labyrinth rupture, carcinomas, circulatory system diseases, autoimmune diseases, brain lesions, mental diseases, congenital or inherited diseases, and so on, are all risk factors for SSHL. Here, we discuss the autoimmune mechanisms behind SSHL, which might be induced by type II–IV allergic reactions. We also introduce the main immunosuppressive medications that have been used to treat SSHL, which will help us to identify potential targets for immune therapy.

Complexity and wide range of neuromyelitis optica spectrum disorders: more than typical manifestations

Neuromyelitis optica (NMO), considered to be mediated by autoantibodies, often cause severely disabling disorders of the central nervous system, and predominantly cause optic nerve damage and longitudinally extensive transverse myelitis. Remarkable progress has been made in deciphering NMO pathogenesis during the past decade. In 2015, the International Panel for NMO Diagnosis proposed the unifying term "NMO spectrum disorders" (NMOSD) and the updated NMOSD criteria reflects a wide range of disease and maintains reasonable specificity. Moreover, cumulative findings have indicated that NMOSD are frequently associated with multiple autoimmune diseases, thereby presenting complex clinical symptoms that make this disease more difficult to recognize. Notably, most neurologists do not heed these symptoms or comorbid conditions in patients with NMOSD. Whereas previous reviews have focused on pathogenesis, treatment, and prognosis in NMOSD, we summarize the present knowledge with particular emphasis on atypical manifestations and autoimmune comorbidities in patients with NMOSD. Furthermore, we emphasized the identification of these atypical characteristics to enable a broader and better understanding of NMOSD, and improve early accurate diagnosis and therapeutic decision making.