A longitudinal study of unilateral Ménière's disease and clinical evolutionary models.

OBJECTIVE: The heterogeneity of Ménière's disease is presently defined by a variety of subtypes. This study introduced three different subtypes of unilateral Ménière's disease based on the evolution of vertigo crises from their inception. METHOD: A longitudinal descriptive study of 327 unilateral Ménière's disease patients was performed. In a subgroup of patients followed from the onset of the disease, 3 subtypes of unilateral Ménière's disease were defined according to the vertiginous crises suffered during the first 10 years of the disorder. RESULTS: Data was available for 87 patients with unilateral Ménière's disease from the start of their disease (26.6 per cent of the original sample). These patients were grouped into three models according to their symptomatic evolution. Model 3 was associated with a worse hearing prognosis, a greater number of Tumarkin's otolithic crises and the need for surgery. Model 1 presented less hearing loss. CONCLUSION: Unilateral Ménière's disease models based on the evolution of vertiginous crises present differences according to aspects such as hearing loss, vertiginous crisis, Tumarkin's otolithic crisis and the need for surgery.

Extended phenotype and clinical subgroups in unilateral Meniere disease: A cross-sectional study with cluster analysis.

OBJECTIVES: To define clinical subgroups by cluster analysis in patients with unilateral Meniere disease (MD) and to compare them with the clinical subgroups found in bilateral MD. DESIGN: A cross-sectional study with a two-step cluster analysis. SETTINGS: A tertiary referral multicenter study. PARTICIPANTS: Nine hundred and eighty-eight adult patients with unilateral MD. MAIN OUTCOME MEASURES: best predictors to define clinical subgroups with potential different aetiologies. RESULTS: We established five clusters in unilateral MD. Group 1 is the most frequently found, includes 53% of patients, and it is defined as the sporadic, classic MD without migraine and without autoimmune disorder (AD). Group 2 is found in 8% of patients, and it is defined by hearing loss, which antedates the vertigo episodes by months or years (delayed MD), without migraine or AD in most of cases. Group 3 involves 13% of patients, and it is considered familial MD, while group 4, which includes 15% of patients, is linked to the presence of migraine in all cases. Group 5 is found in 11% of patients and is defined by a comorbid AD. We found significant differences in the distribution of AD in clusters 3, 4 and 5 between patients with uni- and bilateral MD. CONCLUSIONS: Cluster analysis defines clinical subgroups in MD, and it extends the phenotype beyond audiovestibular symptoms. This classification will help to improve the phenotyping in MD and facilitate the selection of patients for randomised clinical trials.

[The vestibulocollic reflex: assessment and characteristics of vestibular-evoked myogenic potentials analysed by age groups]. / Reflejo vestibulocervical. Valoracion y caracteristicas de los potenciales vestibulares miogenicos evocados analizados por tramos de edad.

INTRODUCTION: Obtaining vestibular-evoked myogenic potentials (VEMP) by means of the vestibulocollic reflex is a readily available technique that provides an image of vestibular functioning and is useful for evaluating the pathologies that involve compromise of the anatomical pathway of the reflex. Although normal patterns do exist, responses vary at different ages. AIM: To obtain reference values of the vestibulocollic reflex according to different age groups. SUBJECTS AND METHODS: We studied 40 volunteers with no symptoms of auditory or vestibular compromise. Each ear was stimulated separately by a series of clicks (sounds lasting 0.1 s; 3 pps; intensities of 100 dB nHL and 85 dB nHL) and recordings were made in the sternocleidomastoid muscles by means of surface electrodes as patients who were lying on their backs contracted these muscles as they lifted their heads. We studied the latency of the initial p13-n23 positive-negative potential and the peak-to-peak amplitude. The existence of later n34-p44 potentials was evaluated. RESULTS: No statistically significant differences were found between genders or between the two ears. We did not find any differences between the latencies of the waves according to the intensity of the stimulus, but there is a relationship between the amplitude of the p13-n23 potential and the intensity of the stimulus. The latencies of the responses in children under 10 years of age differ from those of the other groups, but no differences were found among those over the age of 11. CONCLUSIONS: The VEMP display steady and easily identifiable latencies. We obtained different reference values for latency in children under the age of 10 and those over 11 years old. The amplitude decreases with the intensity of the stimulus.

[Vestibular evoked myogenic potential: a contribution to the vestibular physiology and pathology knowledge. Quantitative patterns in healthy subjects]. / Potencial vestibular miogénico evocado: un aporte al conocimiento de la fisiología y patología vestibular. Patrones cuantitativos en la población normal.

INTRODUCTION: Vestibulocollic reflex is a muscular reflex which is activated by acoustic stimulation. It shows two components: the first one, the vestibular evoked myogenic potential (VMEP) related to the vestibular pathway and the second, to the auditive pathway. The VMEP potential could be useful for vestibular physiology and pathology knowledge. OBJECTIVE: To determine the VMEP's parameters of normality and to evaluate influential factors such as age, sex or stimulation intensity. MATERIAL AND METHODS: Prospective study of the VCR in 40 healthy individuals, distributed in 4 groups according to their age. Stimulation was carried out at 100db and 85db on each ear independently. RESULTS: There are not differences between both ears and sexes. Normal latency levels must be separated between two groups of age: older and younger than 11 years old. Normal absolute values of amplitude response differ depending on muscular contraction, age and stimulation intensity. It is more representative to consider the difference between the values obtained in the two ears of the same individual than to consider the absolute values.