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 aims of this study were to estimate the prevalence of familial cases in patients with Meniere's disease (MD) and to identify clinical differences between sporadic and familial MD. We recruited 1375 patients with definite MD according to the American Academy of Otolaryngology-Head and Neck Surgery criteria, obtaining the familial history of hearing loss or episodic vertigo by direct interview or a postal survey in 1245 cases in a multicenter study. Familial clustering was estimated by the recurrence risk ratio in siblings (λs ) and offspring (λo ) using intermediate and high prevalence values for MD in European population. A total of 431 patients (34%) reported a familial history of hearing loss or recurrent vertigo and 133 patients had a relative with possible MD. After clinical reevaluation, 93 relatives in 76 families were diagnosed of definite MD (8.4%), including three pairs of monozygotic twins. λs and λo were 16-48 and 4-12, respectively. We observed genetic heterogeneity, but most families had an autosomal dominant inheritance with anticipation. No clinical differences were found between sporadic and familial MD, except for an early onset in familial cases. We may conclude that MD has a strong familial aggregation and that sporadic and familial MDs are clinically identical.

Meniere disease (MD) is a heterogeneous clinical condition characterized by sensorineural hearing loss, episodic vestibular symptoms, and tinnitus associated with several comorbidities, such as migraine or autoimmune disorders (AD). The frequency of bilateral involvement may range from 5 to 50%, and it depends on the duration of the disease. We have performed a two-step cluster analysis in 398 patients with bilateral MD (BMD) to identify the best predictors to define clinical subgroups with a potential different etiology to improve the phenotyping of BMD and to develop new treatments. We have defined five clinical variants in BMD. Group 1 is the most frequently found, includes 46% of patients, and is defined by metachronic hearing loss without migraine and without AD. Group 2 is found in 17% of patients, and it is defined by synchronic hearing loss without migraine or AD. Group 3, with 13% of patients, is characterized by familial MD, while group 4, that includes 12% of patients, is associated by the presence of migraine in all cases. Group 5 is found in 11% of patients and is defined by AD. This approach can be helpful in selecting patients for genetic and clinical research. However, further studies will be required to improve the phenotyping in these clinical variants for a better understanding of the diverse etiological factors contributing to BMD.

Epidemiological studies have found a higher prevalence of allergic symptoms and positive prick tests in patients with Meniere’s disease (MD); however the effect of allergenic extracts in MD has not been established. Thus, this study aims to determine the effect of Aspergillus and Penicillium stimulation in cytokine release and gene expression profile in MD. Patients with MD showed higher basal levels of IL-1β, IL-1RA, IL-6 and TNF-α when compared to healthy controls. We observed that IL-1β levels had a bimodal distribution suggesting two different subgroups of patients, with low and high basal levels of cytokines. Gene expression profile in peripheral blood mononuclear cells (PBMC) showed significant differences in patients with high and low basal levels of IL-1β. We found that both mold extracts triggered a significant release of TNF-α in MD patients, which were not found in controls. Moreover, after mold stimulation, MD patients showed a different gene expression profile in PBMC, according to the basal levels of IL-1β. The results indicate that a subset of MD patients have higher basal levels of proinflammatory cytokines and the exposure to Aspergillus and Penicillium extracts may trigger additional TNF-α release and contribute to exacerbate inflammation.

Type 1 Gaucher disease (GD1) is characterised by lack of central nervous system involvement; however, there are several reports of associated neurological manifestations. The aim of this study was to systematically evaluate neurological manifestations in 31 patients with GD1 (12 males and 19 females; mean age 39.4 (range 5-77) years). Participants underwent a complete neurological examination and cognitive tests. Investigation of symptoms and medication intake, and motor and sensory electroneurograms were obtained. 30.7% of adult patients had neurological deficits, including psychomotor delay, parkinsonism, dementia, impaired saccadic ocular movements and peripheral nerve dysfunction. Three patients were redefined as type 3 GD. Electrodiagnosis was performed on 15 patients; 26.7% had reduced amplitude and/or abnormal waveforms in at least three nerves, 33.3% had a mild reduction in amplitude of two nerves and 40% had amplitude reduction in one nerve. Patients with three or more affected nerves had additional neurological symptoms. Our results demonstrate that neurological alterations occur in patients diagnosed with GD1, and subclinical peripheral neuropathy is a frequent finding.