Study of vestibular evoked myogenic potentials in unilateral vestibulopathy: Otolithic versus canal function testing.

OBJECTIVE: The study provides a qualitative evaluation of unilateral vestibulopathy by comparing otolithic and canal function, to establish possible relationships between the type of dysfunction observed and the evolving clinical pictures associated with it. STUDY DESIGN: Retrospective study of a series of cases. SETTING: Department of Medical-Surgical Specialization, Otolaryngology and Cervicofacial Surgery Division, University of Perugia, Perugia, Italy. PATIENTS: Twenty patients whose medical history showed at least one episode corresponding to the clinical parameters of acute vestibulopathy. INTERVENTIONS: Study of vestibular function by recording VEMPs and repeating canal function testing at least 6 months after the first episode of vertigo. MAIN OUTCOME MEASURES: Relationship between the type of vestibulopathy (canal and otolithic) and the clinical pictures observed. RESULTS: Paroxysmal positional vertigo, observed in 4 patients, was correlated with the presence of vestibular evoked myogenic potentials (VEMPs) and the absence of an ipsilateral canal response in all cases (100%). Persistent dizziness was observed in nine patients, and VEMPs were absent in all of them (100%); three (33.3%) showed the recovery of previously absent canal function. Comparison of responses in six patients with recurrent acute vestibulopathy showed persistent and complete loss of canal function in five cases (83.3%), whereas impairment of otolithic response was less constant (40%). CONCLUSION: The combined VEMPs-canal test study shows predictive value regarding certain evolving clinical pictures of vestibulopathy. The absence of VEMPs confirms the role of otolithic dysfunction in the onset of dizziness. Likewise, it suggests that a vestibular origin of these disorders should be considered in cases that have shown aspecific symptoms since onset, without frank vertigo and with normal vestibular response to canal function testing.

Antifungal immune reactivity in nasal polyposis.

As a fungal etiology has been proposed to underlie severe nasal polyposis, the present study was undertaken to assess local antifungal immune reactivity in nasal polyposis. For this purpose, microbial colonization, along with the pattern of T helper 1 (Th1)/Th2 cytokine production and Toll-like receptor (TLR) expression, was evaluated in patients with nasal symptoms and with and without polyposis and in healthy subjects. The results show that Th2 reactivity was a common finding for patients with nasal polyposis regardless of the presence of microbes. The production of interleukin-10 was elevated in patients with bacterial and, particularly, fungal colonization, while both TLR2 expression and TLR4 expression were locally impaired in microbe-colonized patients. Eosinophils and neutrophils, highly recruited in nasal polyposis, were found to exert potent antifungal effector activities toward conidia and hyphae of the fungus and to be positively regulated by TLR2 or TLR4 stimulation. Therefore, a local imbalance between activating and deactivating signals to effector cells may likely contribute to fungal pathogenicity and the expression of local immune reactivity in nasal polyposis.