Inadequate opening capacity of the eustachian tube in Meniere's disease.

CONCLUSION: In this physiological study subjects with Meniere's disease (MD) had high resistance to opening of the eustachian tube (ET) in three of four provocation tests. These subjects can be exposed to pressure deviations in the middle ear (ME) above their equalizing capacity. Transmission of the pressure deviations to the inner ear fluids and influence of the symptoms of MD are feasible. OBJECTIVE: The aim of the study was to reveal potential inadequacy in the ET equilibration capacity and deviations in ME pressure in patients with MD. METHODS: Direct ME pressure measurements were made during provocation tests of the ET, and continuously during the daytime and night-time in 21 patients with unilateral, definite and active MD. Twenty subjects with healthy ears (HEs) were used for comparison. RESULTS: In all, 15/21 subjects could not equilibrate an induced positive and/or negative pressure in the ME by deglutition; 9/21 subjects were not able to perform Valsalva's manoeuvre. All the controls could effectively perform these manoeuvres. However, the continuous measurements showed a similar pressure pattern in patients with MD and the controls, i.e. a slightly negative mean ME pressure during the daytime and positive pressure during sleep.

Middle ear pressure equilibration ability and spontaneous pressure changes in healthy ears with ventilation tubes.

CONCLUSION: The results of this study give support to the theory that opening the middle ear (ME) to the atmosphere leads to a deterioration in its pressure regulation capacity. However, this is probably not the reason why a perforation of the tympanic membrane becomes chronic. OBJECTIVE: Direct, continuous measurement is a method of studying ME pressure regulation. We found previously that subjects with chronic central perforation (CCP) had a negative ME pressure in the daytime, in contrast to subjects with healthy ears. In this study, in order to elucidate the cause of this negative pressure, measurements were performed in healthy ears with ventilation tubes (VTs). MATERIAL AND METHODS: A VT was inserted 1 week prior to the measurements in 18 subjects. A hearing protector was tightly fitted deep into the external ear canal and connected to a portable system consisting of a pressure transducer and a memory. RESULTS: The measurements revealed a mean ME pressure during the first 3 h of -27 daPa. Ten subjects showed an initial decrease in pressure leading to a considerable negative mean ME pressure and a poor ability to equilibrate pressure differences through the Eustachian tube, like the subjects with CCP.

Allergic rhinitis and atopy in 18-year-old students.

BACKGROUND: The aim of this study was to investigate the prevalence of allergic rhinitis and atopy in adolescents and whether air pollution in their schools contributed to allergic sensitization. METHODS: Analyses were performed in 1992-1994 on 511 18-year-old students at four schools and on the indoor air and floor dust of their classrooms. The students underwent skin-prick tests (SPTs) and a nasal lavage and answered a computer-based questionnaire containing questions on allergy and nasal symptoms. RESULTS: Atopy, defined as at least one positive SPT response, was found among 37% of the students, with no difference between students of the four schools, regardless of whether the data were adjusted for gender, hereditary disposition to allergy, and smoking habits. The number of students who had positive SPT and reported nasal symptoms when exposed to possible allergens, which were found among 35%, did not differ between the schools. No correlation was found between the prevalence of atopic individuals and the levels of different indoor air pollutants in the schools. CONCLUSION: The prevalence of allergic rhinitis among adolescents is very high and suggests that it is, at least at the time of our study and in comparison with other studies, still increasing. Our results indicate that the indoor air and floor dust at the schools of the students do not contribute to allergic sensitization.