A. Ivarsson

The Normal Function of the Eustachian Tube: A Study of 102 Cases

A method permitting quantitative tubal function tests across an intact tympanic membrane has been worked out. The method permits a continuous recording of the volume deviation of the drum in relation to the neutral position both at changes of the ambient pressure and changes of the pressure in the middle ear. Repeated testings have been performed on 102 cases with normal ears which all had normal hearing, i.e. a normal audiogram, and normal ear findings. 64 % could equilibrate under dynamic pressure conditions, i.e. simulated descent, 84 % could propagate a square wave pressure from the rhinopharynx to the ear and 79 % had a positive Toynbees test. 12 % could equilibrate negative ear pressures completely while the rest have a reduced capacity to equilibrate or none at all, though the ears were regarded as normal. The findings are discussed.

Eustachian Tube Function in Normal Children and Adults

Eustachian tubal function was studied in 85 otologically healthy children, 3-12 years of age. Middle ear pressure and muscular opening function was measured by tympanometry performed in a pressure chamber, and the results were compared with those obtained from 92 normal adults. Children were found to have a less good muscular opening function and more negative middle ear pressures within wider ranges, compared with adults. Improvement was also seen in children with increasing age. The results seemed to indicate a relation between muscular opening function and middle ear pressure. Even if it were possible to grade the muscular opening function by means of the test procedure, it would still not be possible to define what should be regarded as normal or abnormal tubal function. This report is the first in a series of tubal function studies in normal children.

Immediate Restoration of Basal Sensorineural Hearing (Mb Meniere) Using a Pressure Chamber

A new technique for the restoration of basal sensorineural hearing loss in Mb Meniere was described. Three cases with unilateral basal sensorineural hearing loss, fullness of the ear, and tinnitus were reported. In the acute stage of their disease the patients were treated in a pressure chamber where it was possible to increase or decrease the air pressure within the range +/- 110 cm H2O. The equilibration of middle ear pressures to surrounding air pressures was checked. Exposure to underpressure resulted in a rise of the hearing thresholds at low frequencies and relief of subjective symptoms. When the air pressure was increased the hearing thresholds were lowered and the sensation of tinnitus and fullness of the ear was accentuated. Changes in air pressure did not affect the healthy ears or the high frequencies in the diseased ear. Hearing improvement attained at exposure to underpressure seemed to remain at atmospheric pressure level. The investigation was performed on the hypothesis that a distended membranous labyrinth might cause a venous congestion of the vestibular aqueduct, resulting in impaired endolymph absorption in the endolymphatic sac. Possible effects of changes in environmental air pressure on the inner ear were discussed.

Vertigo due to relative overpressure in the middle ear. An experimental study in man.

It was possible to elicit vertigo in 5 out of 79 otologically healthy subjects by exposure to simulated ascents and passive clearing of the ears. The experimental situation closely resembled the real situation during flying and diving since most pilots and divers usually do not clear their ears actively at ascents, but wait for the ears to be cleared passively when the relative overpressure in the middle ears is great enough to force the Eustachian tubes open. The subjects who reported vertigo were found to have a high forcing pressure on one side when compared with the mean value of 79 normal subjects. Nystagmus was seen synchronous with every period of vertigo, and it was found that the vestibular stimulation was not induced at the moment of pressure regulation as an effect of sudden movements of the stapes, but during the period of asymmetric middle ear pressure and not until the relative overpressure in the “not-cleared” ear had reached a certain level.Bei 5 von 79 otologisch gesunden Versuchspersonen...

A Method for Studies of the Middle Ear Mechanics

A method for studying the middle ear mechanics is described. It is a further development of a method described by Ingelstedt et al. (1967). The basic principle is the recording of the volume deviation of the tympanic membrane during and after changes of the ambient as well as the intratympanic pressure. The method permits quantitative studies of the elastic properties of the tympanic membrane system during both static and dynamic pressure conditions. The volume of the closed airfilled middle ear can be determined, as can the tubal function during both static and dynamic conditions. A new way to determine the middle ear pressure is presented.

Immediate Relief of Symptoms During Acute Attacks of Meniere's Disease, Using a Pressure Chamber

Five patients with Menieres disease were exposed to underpressure in a pressure chamber while suffering from acute attacks with vertigo, nausea, tinnitus and fullness of the ear. Spontaneous nystagmus was the objective criterion for the selection of suitable cases. Subjective as well as objective symptoms subsided much faster than they do with other kinds of treatment. Four patients were free from symptoms within 40 minutes, while the fifth case still complained of vertigo, tinnitus and fullness of the ear after the treatment. However, the symptoms were less severe. A mechanism is discussed by means of which an ambient pressure decrease might cause a reduction of the endolymphatic volume, thus relieving acute symptoms of Menieres disease.

Effects of phenylpropanolamine on ostial and nasal patency in patients treated for chronic maxillary sinusitis.

Ostial and nasal patency were measured in different body positions and after phenylpropanolamine (Ppa) treatment in 12 patients earlier treated for chronic unilateral maxillary sinusitis of varying severity. Six of the sinuses were of normal appearance on sinoscopy. Phenylpropanolamine in a single dose of 100 mg was found to increase the equivalent ostial diameter significantly in the sitting and recumbent positions. The drug also reduced the nasal airway resistance. The Ppa effect might be of benefit in patients treated for chronic maxillary sinusitis.

Rhinomanometry:I. Simple equipment

A rhinomanometer for clinical work and research is presented. It adheres to the principle that pressure and flow should be recorded X-Y wise. A storage oscilloscope is used and the tracing pencilled down on a preprinted diagram via an oscillotracer. Anterior and posterior rhinomanometry can be performed. In the former variety, one nostril is occluded and connected to the pressure transducer by an adhesive tape. This does not deform or irritate the nasal airway. A mask for anaesthesia connects the nose to the pneumotachograph. Miniature transducers mounted on the pneumotachograph provide mechanical advantages. Simple means that allow dynamic calibration of the rhinomanometer are described. The cost to set up and operate the equipment is low.

The Elastic Properties of the Tympanic Membrane System

A method has been worked out for recording the volume displacement of the drum towards the closed middle ear as a function of the pressure change in the ear canal. From these recordings we can calculate the elastic properties of the tympanic membrane system. Studies of this kind have not been published previously. In 101 cases with normal ears we found a varying degree of mobility of the drum. The mobility increases in cases with a slightly reduced tubal function as compared with cases with a perfect tubal function. This finding is explained by an increased pressure load on the tympanic membrane system when the pressure regulating capacity of the tube is reduced. The present method seems to facilitate analysis of pathological processes in the middle ear.

Pressure-dependent variation in volume of mucosal lining of the middle ear

A method is described for studying pressure-dependent variation in the volume of the mucosa of the middle ear. Studies were performed at different pressures in the middle ear as well as at different ambient pressures. It was found that the pressure-dependent volumetric changes of the mucosa were the same whether the pressure in the middle ear was changed directly by altering the intratympanic or indirectly by altering the ambient pressure. With the method described it is also possible to determine the middle ear volume without artefacts due to the middle ear mucosa. The volume-pressure relationship of the middle ear mucosa varied from 0.6 to 1.7 mul/cm H2O and linearly with the volume of the middle ear. Comparisons between determinations of the middle ear volume with and without consideration of the mucosal compliance showed differences, especially in small middle ears. The effect on the volume of the mucosa caused by variation of posture was also studied. The physiological middle ear pressure depends on the functional state of the Eustachian tube, the middle ear volume, the tympanic membrane and the middle ear mucosa. Thus, knowledge of the mucosa compliance is important for calculating middle ear pressure as well as for determining the volume of the air-filled middle ear space. The method might also prove a useful tool in the elucidation of the vascular bed both in health and in disease as well as the reaction of the mucosal vessels to drugs.