Paz Pérez-Vázquez

Objective: The head impulse test (HIT) is triggered by the vestibulo-ocular reflex (VOR), complemented by the optokinetic and pursuit systems. This study aimed to evaluate the possibility of individualizing the VOR contribution to the HIT. Design: Thirty-six healthy individuals (19 males, 17 females; age 21–64 years, mean 39 years) underwent horizontal video HIT (vHIT). This was first conducted in darkness, without visual fixation, and then visually tracked. Results: Seventy percent of the impulses delivered ocular responses opposite to the direction of the head, matching its velocity to a point where quick anticompensatory eye movements (SQEM) stopped the response (SQEM mean latency 58.21 ms, interquartile range 50–67 ms). Of these, 75% recaptured the head velocity after culmination. Thirty percent of the responses completed a bell-shaped curve. The completed bell-shaped curve gains and instantaneous gains (at 40, 60, and 80 ms) before SQEM were equivalent for both paradigms. Females completed more bell-shaped traces (42%) than males (15%); p = 0.01. The SQEM latency was longer (62.81 versus 55.71 ms, p < 0.01), and the time to recapture the bell-shaped curve was shorter (77.51 versus 92.52 ms, p < 0.01) in females than in males. The gains were comparable between sexes in both paradigms. Conclusions: The VOR effect can be localized in the first 70 ms of the vHIT response. In addition, other influences may take place in estimating the vHIT responses. The study of these influences might provide useful information that can be applied to patient management.

Objectives: Meniere’s disease (MD) is a rare inner ear disorder characterized by sensorineural hearing loss, episodic vertigo, and tinnitus. Familial MD has been reported in 6 to 9% of sporadic cases, and few genes including FAM136A, DTNA, PRKCB, SEMA3D, and DPT have been involved in single families, suggesting genetic heterogeneity. In this study, the authors recruited 46 families with MD to search for relevant candidate genes for hearing loss in familial MD. Design: Exome sequencing data from MD patients were analyzed to search for rare variants in hearing loss genes in a case-control study. A total of 109 patients with MD (73 familial cases and 36 early-onset sporadic patients) diagnosed according to the diagnostic criteria defined by the Barany Society were recruited in 11 hospitals. The allelic frequencies of rare variants in hearing loss genes were calculated in individuals with familial MD. A single rare variant analysis and a gene burden analysis (GBA) were conducted in the dataset selecting 1 patient from each family. Allelic frequencies from European and Spanish reference datasets were used as controls. Results: A total of 5136 single-nucleotide variants in hearing loss genes were considered for single rare variant analysis in familial MD cases, but only 1 heterozygous likely pathogenic variant in the OTOG gene (rs552304627) was found in 2 unrelated families. The gene burden analysis found an enrichment of rare missense variants in the OTOG gene in familial MD. So, 15 of 46 families (33%) showed at least 1 rare missense variant in the OTOG gene, suggesting a key role in familial MD. Conclusions: The authors found an enrichment of multiplex rare missense variants in the OTOG gene in familial MD. This finding supports OTOG as a relevant gene in familial MD and set the groundwork for genetic testing in MD.

Objective: To determine the reliability and safety of posterior canal BPPV (pc-BPPV) treatment with subsequent assessment of the effectiveness of the maneuver in a single session, compared to the classic weekly procedure. Method: A prospective study of two randomized groups of unilateral pc-BPPV was performed: a weekly management group (27 patients) and single-session treatment group (26 patients). The number of maneuvers required to clear pc-BPPV, incidence of side effects (re-entries and canal conversions), and recurrence rates were compared. Results: There were no statistically significant differences in the number of maneuvers needed to resolve pc-BPPV, the incidence of side effects, or the recurrence rate between the two groups. Two re-entries were diagnosed in the single-session group, and both were easily and successfully treated. Three early recurrences were found in the single-session group and one spontaneous recovery was encountered in the weekly group. Time required to discharge patients to follow-up was significantly reduced in the single-session group. Conclusion: Managing pc-BPPV in one session is safe and reliable, resulting in fewer visits to outpatient clinics and optimization of treatment strategies.

Objectives: Meniere’s disease (MD) is a rare inner ear disorder characterized by sensorineural hearing loss, episodic vertigo and tinnitus. Familial MD has been reported in 6-9% of sporadic cases, and few genes including FAM136A, DTNA, PRKCB, SEMA3D and DPT have been involved in single families, suggesting genetic heterogeneity. In this study, the authors recruited 46 families with MD to search for relevant candidate genes for hearing loss in familial MD. Design: Exome sequencing data from MD patients were analyzed to search for rare variants in hearing loss genes in a case-control study. A total of 109 patients with MD (73 familial cases and 36 early-onset sporadic patients) diagnosed according to the diagnostic criteria defined by the Barany Society were recruited in 11 hospitals. The allelic frequencies of rare variants in hearing loss genes were calculated in individuals with familial MD. A single rare variant analysis (SRVA) and a gene burden analysis (GBA) were conducted in the dataset selecting one patient from each family. Allelic frequencies from European and Spanish reference datasets were used as controls. Results: A total of 5136 single nucleotide variants in hearing loss genes were considered for SRVA in familial MD cases, but only one heterozygous variant in the OTOG gene (rs552304627) was found in two unrelated families. The GBA found an enrichment of rare missense variants in the OTOG gene in familial MD. So, 15/46 families (33%) showed at least one rare missense variant in the OTOG gene, suggesting a key role in familial MD. Conclusions: The authors found an enrichment of multiplex rare missense variants in the OTOG gene in familial MD. This finding supports OTOG as a relevant gene in familial MD and set the groundwork for genetic testing in MD.

OBJECTIVE: To assess the effect of intratympanic methylprednisolone (ITMP) in posterior canal benign paroxysmal positional vertigo (BPPV) that fails treatment involving repositioning maneuver in a case series. MATERIALS and METHODS: Nine patients with persistent posterior canal BPPV after 6 or more repositioning maneuvers were treated by ITMP (two weekly doses of 0.3–0.4 mL at 40 mg/mL) before repeating the repositioning procedures. RESULTS: Following ITMP treatment, 7 out of 9 patients were relieved of their symptoms and did not exhibit positional nystagmus after 1 or 2 repositioning maneuvers. The number of positional maneuvers performed before and after ITMP treatment in these 7 patients showed a statistically significant (p=0.016) reduction in the amount of repositioning treatments required. None of the 7 respondent patients showed any relapses during the follow-up period (follow-up range: 11–95 months). CONCLUSION: Administering ITMP before resuming repositioning procedures can be a useful treatment for persistent BPPV of the posterior canal.

Introducción y objetivo: La prueba calórica es una de las pruebas funcionales vestibulares que más han sido empleadas en la clínica. Se realiza una revisión con un enfoque práctico de su metodología y de la interpretación de sus resultados. Método: revisión narrativa. Resultados y Discusión: La prueba está sujeta a ciertas limitaciones, como ser sólo indicativa de la función del conducto semicircular horizontal y no tener valores absolutos de normalidad. Esto condiciona su realización y el análisis de sus resultados, que deben ser interpretados con cautela. Para interpretar correctamenteel test es necesario descartar y corregir artefactos y errores técnicos. Conclusiones: El test calórico sigue siendo una prueba muy útil, sobre todo por su capacidad para marcar el lado patológico. Pero debe ser puesta en el contexto clínico del paciente y combinarse con el resto de las exploraciones funcionales vestibulares para poder aproximar un diagnóstico o plantear un tratamiento.

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.

Benign paroxysmal positional vertigo (BPPV) is the most frequent episodic vestibular disorder. It is due to otolith rests that are free into the canals or attached to the cupulas. Well over 90% of patients can be successfully treated with manoeuvres that move the particles back to the utriculus. Among the great variety of procedures that have been described, the manoeuvres that are supported by evidenced-based studies or extensive series are commented in this review. Some topics regarding BPPV treatment, such as controlling the accuracy of the procedures or the utility of post-manoeuvre restrictions are also discussed.