Symposium on the Role of the Vestibular Organs in Space Exploration (1970) / Chapter Skim
Currently Skimming:
EXPERIMENTAL AND CLINICAL EXPERIENCES AND COMMENTS ON ULTRASONIC TREATMENT OF MENIERE'S DISEASE
EXPERIMENTAL AND CLINICAL EXPERIENCES AND COMMENTS ON ULTRASONIC TREATMENT OF MENIERE'S DISEASE
Pages 271-284
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 271... ...
A clinical followup investigation of 228 consecutive patients revealed the following: Freedom from or considerable improvement in vertigo was found in 89 percent; tinnitus had diminished or disappeared in 48 percent: hearing was improved or unchanged in 64 percent; and caloric reaction was clearly reduced in 58 percent. Of the last 200 surgical patients, we have only one with transitory facial paralysis, or a 0.5-percent incidence.
|
From page 272... ...
It should be noted that this is a select series of severely disabled patients, in whom no form of medication had had an effect. Some of the patients were from Uppsala, but the majority had been referred to us from different parts of our country.
|
From page 273... ...
perhaps he may be visiting a museum or art exhibition wearing bifocal spectacles and will have to bend and turn his head in time with his different up-and-down eye movements. It has been considered pathogenetically that, on rotatory movements of the head, excitation of sympathetic vasomotor fibers may be induced, so that a spasm is provoked in the vertebral artery.
|
From page 274... ...
With the presence of lesions in the cervical spinal column, rotation of the head can produce brainstem symptoms with vertigo and syncope, or what is called the "syncopal cervical vertebral symptoms." It would thus seem that the cervical syndrome is the result of a unilateral vertebral occlusion that is not immediately compensated by adequate collateral supply on the opposite side from a well-functioning circle of Willis. The vestibular nuclei are very vulnerable, since they are supplied by narrow end arteries.
|
From page 275... ...
The new type with Teflon tips is shown in figures 3 and 4. Criticisms have been voiced against ultrasonic treatment of Mpniere's disease, mainly because of the relatively high incidence of facial paralysis that constitutes the only serious complication of this form of treatment.
|
From page 276... ...
With regard to the irradiation technique, I should like to mention that a good surface for application of the Teflon tip is created by boring a rounded hollow at the junction between the horizontal and the upper vertical semicircular canals (fig.
|
From page 277... ...
The handle contains titanium, which has an acoustic impedance close to that of lead zirconate. Titanium absorbs and damps extra oscillations in the barium titanate crystal.
|
From page 278... ...
RESULTS AND DISCUSSION In ultrasonic treatment it is a combination of thermal, mechanical, and chemical influences which gives the biological effect. In order to avoid damage to the facial nerve and to preserve hearing to the highest possible extent, a study had to be made of the way in which the heat energy was distributed in the bone.
|
From page 279... ...
lower ultrasonic power the temperature increase was of the same magnitude as in temporal bone preparations, but with higher power the increase was smaller than in the preparations, probably due to heat losses via the circulating blood. Ultrasonic irradiation of rabbits placed in different body positions showed that nystagmus changed its direction when the rabbit was rotated 180°.
|
From page 280... ...
Experimental therapy in rabbits and treatment of human beings with the head in different positions have shown that the initial nystagmus caused by ultrasound is probably a caloric reaction provoked by the endolymphatic flow caused by the thermal effect. Experimental temperature studies on ultrasonic irradiation of human temporal bone preparations and in man during labyrinthectomy have shown that the temperature increase in the cochlea is negligible and that the critical temperature in the facial nerve is not reached until after more than 4 minutes of irradiation.
|
From page 281... ...
In spite of the fact that, in this way, the labyrinth may perhaps for the moment seem to show no reaction to calorization -- i.e., it may seem habituated to the thermal effect of the ultrasound -- a distinct irritative nystagmus of homolateral direction can nevertheless often be seen and can fairly quickly change to a contralateral direction during further irradiation (fig.
|
From page 282... ...
In other words, it would seem that all these biochemical changes after ultrasonic irradiation, which among other things causes damage to the secretory epithelium in the cochlea and ampullae, might theoretically explain not only the favorable effect of such irradiation in Meniere's disease but also the positive results which have been obtained without always producing full destruction of the sensory cells of the vestibular organ. In this connection it is also of interest to remember the beneficial effect of our diuretics in Meniere's disease.
|
From page 283... ...
It is conceivable that there are very considerable regional differences, because I believe that the consensus of American otologists is probably that Meniere's disease is by no means the most frequent affliction and that benign positional vertigo and so forth occur much more frequently. Do you have any comments on this?
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.