Atypical periodic alternating nystagmus responding to high-dose intravenous immunoglobulins: a case report.

BACKGROUND: Acquired periodic alternating nystagmus (PAN) is a rare but well-defined syndrome that consists of a horizontal nystagmus that cyclically reverses its direction. PAN can be caused by degenerative, neoplastic, or toxic diseases of the cerebellum and, in a few cases, by subacute cerebellar ataxia of immune origin. CASE PRESENTATION: A 44-year-old man came to our attention because of rapidly progressive gait instability and blurred vision. Clinical examination showed PAN and a mild pancerebellar syndrome. Eye movement recordings disclosed a short cycle PAN with significant slow-phase velocity only in darkness. Under the effect of a γ-aminobutyric acid type B (GABAB) agonist, PAN was not modified. Right after treatment with intravenous immunoglobulin (IVIg) was started, PAN was essentially eliminated. Three months after last dose of IVIg, this nystagmus reappeared. CONCLUSIONS: IVIg resolved PAN in this patient. This finding may point to an autoimmune mechanism underlying this patient's nystagmus. This case suggests that the usefulness of IVIg at treating PAN might be worth a consideration in similar clinical settings.

Ipsilesional Nystagmus Induced by Vibration in Subjects With Ménière's Disease or Vestibular Schwannoma.

OBJECTIVE: To analyze the frequency in which vibration-induced nystagmus (VIN) with ipsilesional direction appears in subjects with Ménière's disease (MD) or vestibular schwannoma (VS). STUDY DESIGN: Cross-sectional study. SETTING: Tertiary referral center. PATIENTS: Fifty-two subjects with MD and 21 subjects with vestibular schwannoma. INTERVENTION: Videonystagmographic recordings of VIN at 30, 60, and 100 Hz. MAIN OUTCOME MEASURES: Direction and slow phase velocity of VIN at 30, 60, and 100 Hz. RESULTS: Ipsilesional Nystagmus was observed in 8 of 52 subjects with MD (15.4%) and in 11 of 21 subjects affected of unilateral VS (52.4%). Ipsilesional nystagmus was significantly higher in patients with VS (p = 0.003). The frequency of appearance of ipsilesional nystagmus in the subjects with VS who has not been treated was significantly higher than those who underwent radiosurgery (84.6% vs 0%, p = 0.046). CONCLUSION: Ipsilesional vibration-induced Nystagmus can be present in subjects with vestibular deficits caused by MD and VS.

Regulation of Fn14 Receptor and NF-κB Underlies Inflammation in Meniere's Disease.

Meniere's disease (MD) is a rare disorder characterized by episodic vertigo, sensorineural hearing loss, tinnitus, and aural fullness. It is associated with a fluid imbalance between the secretion of endolymph in the cochlear duct and its reabsorption into the subarachnoid space, leading to an accumulation of endolymph in the inner ear. Epidemiological evidence, including familial aggregation, indicates a genetic contribution and a consistent association with autoimmune diseases (AD). We conducted a case-control study in two phases using an immune genotyping array in a total of 420 patients with bilateral MD and 1,630 controls. We have identified the first locus, at 6p21.33, suggesting an association with bilateral MD [meta-analysis leading signal rs4947296, OR = 2.089 (1.661-2.627); p = 1.39 × 10-09]. Gene expression profiles of homozygous genotype-selected peripheral blood mononuclear cells (PBMCs) demonstrated that this region is a trans-expression quantitative trait locus (eQTL) in PBMCs. Signaling analysis predicted several tumor necrosis factor-related pathways, the TWEAK/Fn14 pathway being the top candidate (p = 2.42 × 10-11). This pathway is involved in the modulation of inflammation in several human AD, including multiple sclerosis, systemic lupus erythematosus, or rheumatoid arthritis. In vitro studies with genotype-selected lymphoblastoid cells from patients with MD suggest that this trans-eQTL may regulate cellular proliferation in lymphoid cells through the TWEAK/Fn14 pathway by increasing the translation of NF-κB. Taken together; these findings suggest that the carriers of the risk genotype may develop an NF-κB-mediated inflammatory response in MD.

Allelic variants in TLR10 gene may influence bilateral affectation and clinical course of Meniere's disease.

Toll-like receptors trigger the innate immune response by activating various cell types such us macrophages and lymphocytes. We genotyped SNV of TLR3, TRL7, TLR8 and TLR10 in 863 Spanish and 150 Italian patients with Meniere's disease (MD) and 1,013 controls by using Taqman assays. Real-Time qPCR was used to measure the expression level of TLR10 in peripheral blood leukocytes. The overall dataset showed that the C allele and the CC genotype of rs11096955 in TLR10 gene were more commonly observed in controls than patients (corrected p = 1 × 10(-3), OR = 0.68 [95 % confidence interval, 0.54-0.84] for CC genotype; corrected p = 1.5 × 10(-5), OR = 0.75 [0.66-0.85] for allele C). Moreover, the CC genotype was more frequent in patients with uni- (19 %) than bilateral sensorineural hearing loss (SNHL) (13 %). Logistic regression demonstrated that the time since the onset of MD, Tumarkin crises, hearing stage and rs11096955 were independent factors influencing the risk of bilateral SNHL. In addition, rs11096955 influenced hearing loss progression in patients with bilateral MD. No change in expression of TLR10 was observed according to CC, CA or AA genotypes. Our data suggest that allelic variants of TLR10 gene may influence the susceptibility and time-course of hearing loss of MD in the European population.

Functional variants of MIF, INFG and TFNA genes are not associated with disease susceptibility or hearing loss progression in patients with Ménière's disease.

Variability in acute immune response genes could determine susceptibility or prognosis for Ménière's disease (MD). The cytokines tumor necrosis factor α (TNFα), macrophage migration inhibitory factor (MIF) and interferon γ (INFγ) are proinflammatory cytokines of the innate immune response. These cytokines mediate inflammation and have been previously associated with the inflammatory process in several autoimmune diseases. We investigated the association between functional allelic variants of MIF (rs35688089), IFNG (rs2234688) and TNFA (rs1800629) in patients with MD. In addition to testing these variants for an association with disease, we also tested for an association with clinical aspects of disease progression, such as persistence of vertigo and the sensorineural hearing loss. A total of 580 patients with diagnosis of definite MD, according to the diagnostic scale of the American Academy of Otolaryngology-Head and Neck Surgery, and 552 healthy controls were included. DNA samples from a set of 291 American patients were used to confirm the results obtained in the MIF gene in our Spanish cohort. Although we found a significant association with the allele containing five repeats of CATT within the MIF gene in patients with MD in the Spanish cohort [corrected p = 0.008, OR = 0.69 (95 % CI, 0.54-0.88)], this finding could not be replicated in the American set. Moreover, no genetic associations for variants in either the TNFA or IFNG genes and MD were found. These results support the conclusion that functional variants of MIF, INFG, and TFNA genes are not associated with disease susceptibility or hearing loss progression in patients with MD.

High prevalence of systemic autoimmune diseases in patients with Menière's disease.

BACKGROUND: Autoimmunity appears to be associated with the pathophysiology of Meniere's disease (MD), an inner ear disorder characterized by episodes of vertigo associated with hearing loss and tinnitus. However, the prevalence of autoimmune diseases (AD) in patients with MD has not been studied in individuals with uni or bilateral sensorineural hearing loss (SNHL). METHODS AND FINDINGS: We estimated the prevalence of AD in 690 outpatients with MD with uni or bilateral SNHL from otoneurology clinics at six tertiary referral hospitals by using clinica criteria and an immune panel (lymphocyte populations, antinuclear antibodies, C3, C4 and proinflammatory cytokines TNFα, INFγ). The observed prevalence of rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and ankylosing spondylitis (AS) was higher than expected for the general population (1.39 for RA, 0.87 for SLE and 0.70 for AS, respectively). Systemic AD were more frequently observed in patients with MD and diagnostic criteria for migraine than cases with MD and tension-type headache (p = 0.007). There were clinical differences between patients with uni or bilateral SNHL, but no differences were found in the immune profile. Multiple linear regression showed that changes in lymphocytes subpopulations were associated with hearing loss and persistence of vertigo, suggesting a role for the immune response in MD. CONCLUSIONS: Despite some limitations, MD displays an elevated prevalence of systemic AD such as RA, SLE and AS. This finding, which suggests an autoimmune background in a subset of patients with MD, has important implications for the treatment of MD.

Functional variants in NOS1 and NOS2A are not associated with progressive hearing loss in Ménière's disease in a European Caucasian population.

Hearing loss in Ménière's disease (MD) is associated with loss of spiral ganglion neurons and hair cells. In a guinea pig model of endolymphatic hydrops, nitric oxide synthases (NOS) and oxidative stress mediate loss of spiral ganglion neurons. To test the hypothesis that functional variants of NOS1 and NOS2A are associated with MD, we genotyped three functional variants of NOS1 (rs41279104, rs2682826, and a cytosine-adenosine microsatellite repeat in exon 1f) and the CCTTT repeat in the promoter of NOS2A gene (rs3833912) in two independent MD sets (273 patients in total) and 550 controls. A third cohort of American patients was genotyped as replication cohort for the CCTTT repeat. Neither allele nor genotype frequencies of rs41279104 and rs2682826 were associated with MD, although longer alleles of the cytosine-adenosine microsatellite repeat were marginally significant (corrected p = 0.05) in the Mediterranean cohort but not in a second Galicia cohort. Shorter numbers of the CCTTT repeat in NOS2A were significantly more frequent in Galicia controls (OR = 0.37 [CI, 0.18-0.76], corrected p = 0.04), but this finding could not be replicated in Mediterranean or American case-control populations. Meta-analysis did not support an association between CCTTT repeats and risk for MD. Severe hearing loss (>75 dB) was also not associated with any functional variants studied. Functional variants of NOS1 and NOS2A do not confer susceptibility for MD.

Hearing assessment in Menière's disease.

OBJECTIVES: To investigate the level of hearing loss and the configuration of the mean audiometric curve over the course of Menière's disease, correcting the data according to patient age. STUDY DESIGN: A retrospective study of 3,963 hearing tests. METHODS: Descriptive, longitudinal study of pure-tone audiometries of 237 patients at a tertiary hospital who had been diagnosed with definitive Menière's disease according to the American Academy of Otorhinolaryngology criteria. All audiometric results were age-corrected, and patients were followed for 1 to 31 years. In patients who had undergone surgery, only the data collected before the operation were assessed. RESULTS: In patients with unilateral disease, the mean hearing loss was characteristically low frequency, even in very advanced stages of the disease. Hearing loss was accentuated at 5 and 15 years from onset. In bilateral cases, hearing loss was slightly more severe and the average loss produced a flatter audiometric curve than in unilateral cases. CONCLUSIONS: In Menière's disease, audiometry results corrected for patient age show an inherent upward-sloping configuration of the mean audiometric curve at all time points during the disease. The hearing pattern differs between unilateral and bilateral disease. The audiometric curve configuration may be an indicator of future bilateral disease.

Novel mutations in the USH1C gene in Usher syndrome patients.

PURPOSE: Usher syndrome type I (USH1) is an autosomal recessive disorder characterized by severe-profound sensorineural hearing loss, retinitis pigmentosa, and vestibular areflexia. To date, five USH1 genes have been identified. One of these genes is Usher syndrome 1C (USH1C), which encodes a protein, harmonin, containing PDZ domains. The aim of the present work was the mutation screening of the USH1C gene in a cohort of 33 Usher syndrome patients, to identify the genetic cause of the disease and to determine the relative involvement of this gene in USH1 pathogenesis in the Spanish population. METHODS: Thirty-three patients were screened for mutations in the USH1C gene by direct sequencing. Some had already been screened for mutations in the other known USH1 genes (myosin VIIA [MYO7A], cadherin-related 23 [CDH23], protocadherin-related 15 [PCDH15], and Usher syndrome 1G [USH1G]), but no mutation was found. RESULTS: Two novel mutations were found in the USH1C gene: a non-sense mutation (p.C224X) and a frame-shift mutation (p.D124TfsX7). These mutations were found in a homozygous state in two unrelated USH1 patients. CONCLUSIONS: In the present study, we detected two novel pathogenic mutations in the USH1C gene. Our results suggest that mutations in USH1C are responsible for 1.5% of USH1 disease in patients of Spanish origin (considering the total cohort of 65 Spanish USH1 patients since 2005), indicating that USH1C is a rare form of USH in this population.

Poly(ADP-ribose) polymerase-1 (PARP-1) longer alleles spanning the promoter region may confer protection to bilateral Meniere's disease.

CONCLUSION: The longer alleles (CA)17-20 of the promoter region of PARP-1 gene may confer some protection against bilateral Meniere's disease (BMD). OBJECTIVE: To analyze microsatellite (CA)(n) polymorphisms in the promoter region of PARP-1 gene and seek out risk and protective variants for BMD. SUBJECTS AND METHODS: Eighty patients from two ethnically defined groups with definite BMD, according to the diagnostic scale of the American Academy of Otolaryngology Head and Neck Surgery, were compared with a group of 371 normal controls from the same origin in a prospective multicenter study. We developed a specific amplification protocol to determine the PARP1-promotor CA microsatellite polymorphisms. RESULTS: We found that the longer alleles (CA)17-20 had a very low frequency in BMD (2/160, 1.3%, OR=7.33 (1.77-30.37, 95% CI), corrected p=0.012), suggesting that it may confer some protection against BMD.

Time course of episodes of definitive vertigo in Meniere's disease.

OBJECTIVE: To evaluate the frequency and duration of episodes of definitive vertigo in Ménière's disease. DESIGN: Prospective longitudinal study. SETTING: Multiple tertiary referral centers. PATIENTS: Five hundred ten individuals from 8 hospitals that met the American Academy of Otolaryngology-Head and Neck Surgery diagnostic criteria for definitive Ménière's disease. INTERVENTION: Conservative treatment. MAIN OUTCOME MEASURE: Frequency and duration of episodes of definitive vertigo during follow-up. RESULTS: Ménière's disease affects both sexes and both ears equally, with onset generally in the fourth decade of life. The number of episodes of vertigo is greater in the first few years of the disease. Although episodes of vertigo that last longer than 6 hours are less frequent than shorter episodes, they occur with similar frequency throughout the natural course of the disease. The percentage of patients without episodes of vertigo increases as the disease progresses, and 70% of patients who did not have an episode of vertigo for 1 year will continue to be free of episodes during the following year. Thus, there is a relationship between the frequency of episodes in consecutive years, although this association decreases rapidly as the number of years increases. CONCLUSION: The frequency of definitive episodes of vertigo in Ménière's disease decreased during follow-up, and many individuals reached a steady-state phase free of vertigo.

HLA-DRB1*1101 allele may be associated with bilateral Méniére's disease in southern European population.

OBJECTIVE: To analyze the associations of HLA-DRB1* and DQB1* Class II alleles in patients with bilateral Méniére's disease (MD). PATIENTS AND METHODS: Eighty patients from two ethnically defined groups with definite bilateral MD, according to the diagnostic scale of the American Academy of Otolaryngology-Head and Neck Surgery, were compared with normal controls from the same origin in a prospective multicenter study. We performed an allele-specific amplification for HLA-DRB1* and DQB1* genes of the major histocompatibility complex. RESULTS: The allele HLA-DRB1*1101 was associated with bilateral MD in the Mediterranean population (odds ratio, 3.65 [95% confidence intervals, 1.5-9.1], corrected p = 0.029); however, this allele was not associated in the group from Galicia (northwest of Spain). No differences were found in the distribution of alleles for the gene HLA-DQB1* between patients and controls. CONCLUSION: The allele HLA-DRB1*1101 and the allelic group HLA-DRB1*11 may determine an increased susceptibility to develop bilateral MD in a southern European population.