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Biomedical subjects

J Stahle

Publications and source records attributed to J Stahle.

83 records · Page 5Linked to original sources
PubMedDate not supplied

Ultrasound treatment of Meniere's disease. Long-term follow-up of 356 advanced cases.

Twelve years' experience of ultrasound treatment of 356 patients is presented. For evaluating the results a new multifacetted scoring system was developed, where each individual patient was evaluated on the basis of four parameters. According to this evaluation 71% of the patients improved after the operation, while 29% remained unchanged or deteriorated. Because of lack of improvement, 42 patients underwent reoperation by different methods; in half of them ultrasonic irradiation was again used. The hearing deteriorated in about 40% of the patients, to which result the long observation times also contributed. The caloric response became reduced in 70% of the patients. Marked depression of the caloric response characterized the patients who were relieved of vertigo. Transient facial paralysis in 4 patients was the only complication.

Adult↗
PubMedDate not supplied

Accumulation of 14C-lidocaine in the inner ear. Preliminary clinical experience utilizing intravenous lidocaine in the treatment of severe tinnitus.

Clinical experience has demonstrated that intravenously administered local anaesthetics have a mitigating effect on severe tinnitus. In an attempt to gain some insight into the mechanism of this effect, autoradiography of the inner ear of young pigmented rats was performed after intravenous injection of 14C-lidocaine. Some accumulation of lidocaine was found in the modiolus, but almost none in the stria vascularis. A large accumulation was observed in other melanincontaining tissues, such as the hair follicles and uvea. The in vitro accumulation of 14C-labelled lidocaine adsorbed on melanin granules was low (12%) as compared with that of other drugs, such as kanamycin (89%) and chloroquine (85%). These autoradiographic results indicate that lidocaine has an effect upon the inner ear, in addition to its previously demonstrated effect on the CNS.

Animals↗
PubMedDate not supplied

Optokinetic test comprising both acceleration and constant velocity stimulation (ACV-OKN test).

Normal subjects were exposed to two kinds of optokinetic stimulation, viz. at speeds of 60 degrees/s and 90 degrees/s preceded by acceleration at 6 degrees/s2 and 4.5 degrees/s2, respectively. In most subjects the speed of the eye in the slow nystagmus phase equalled the speed of the rotating device during the acceleration at velocities up to about 60 degrees/s. The eye then lagged behind the speed of the optokinetic stimulus. The upper limit for linear increase in the eye speed of the slow nystagmus phase has been named the "optokinetic fatigue threshold". A new clinical test permitting quantitative assessment of the optokinetic response has been introduced. The maximum eye speed in the slow nystagmus phase has been found to be the most appropriate parameter. Presentation of the results in the form of special charts, named optokinograms, is recommended. Optokinetic disturbances of varying kinds were noted mostly in patients with CNS disorders, but also in patients with diseases of the inner ear.

Acceleration↗
PubMedDate not supplied

Macula utriculi in four cases with Meniere's disease.

Four patients suffering from Meniere's disease were labyrinthectomized. Maculae utriculi were removed and studied by electron microscopy. The neuro-epithelia from all four patients appeared fairly normal, considering the age of the patients. However, two types of degenerative change, which could be related to the inner ear disorder, could be distinguished. One was vacuolation of the sensory cell cytoplasm, followed by pycnosis of the nucleus and cell death. The other was cystic degeneration. This started with localized separations between the sensory cell and the nerve chalice. These separations developed into a single cystic cavity. A few large intra-epithelial cysts were found, probably representing the final stage of the cystic degenerative process.

Adult↗
PubMedDate not supplied

Ultrasonic irradiation of the guinea pig labyrinth. Correlation of morphology and intralabyrinthine temperature.

The effects of high frequency ultrasound on the inner ear structures after irradiation of the lateral semicircular canal have been analysed by means of light-and electronmicroscopy. Sudden as well as gradual morphological changes in the vestibular sensory epithelium are described. Damage to the connective tissue stroma, blood vessels and nerve fibres characterized the chronic phase. Both cochlear morphology and hearing remained normal after irradiation of some behaviorally conditioned animals. The temperature rise in the labyrinth during continuous irradiation was studied. The experiments indicated that the mechanical effects may be more significant than the thermal in explaining the structural changes of the inner ear of guinea pigs. The results are compared with previous extensive experience of ultrasound treatment of patients with Meniere's disease.

Animals↗
PubMedDate not supplied

Immunodefence of the inner ear? Lymphocyte-macrophage interaction in the endolymphatic sac.

Owing to their proximity to areas exposed to infection, the sensory organs of the inner ear are probably dependent on an efficient antimicrobial defence. The longitudinal flow of endolymph to the endolymphatic sac may be of major importance in this context. Substances entering the ear can be automatically carried to the distal part of the endolymphatic duct, where lymphoid cells are present and endolymphatic phagocytosis occurs. In the intermediate part of the epithelium of the sac morphological signs marking the incoming substances are present. A vigorous interaction between lymphocytes and macrophages, similar to that observed in antigen-activated lymphoid tissue, may be seen. The sac is here surrounded by a rich network of lymphatic capillaries and blood vessels.

Animals↗
PubMedDate not supplied

The temporal bone in patients with Meniere's disease.

Sixty-three patients with Meniere's disease were compared with a group of healthy individuals with respect to findings at tomography and plain radiography. The temporal bone in patients differed in many respects from that in the healthy controls. Characteristic features in patients were a lack of periaqueductal pneumatization, a lack of pneumatization medial to the arcuate eminence, a short vestibular aqueduct, a narrow external aperture of the vestibular aqueduct, and a reduction in size of the mastoid air cell system. The mean mastoid area in the diseased ear in patients was 7.93 cm2 and in controls 11.59 cm2. The vestibular aqueduct was visible in its full length on tomograms in 81% of the healthy controls and in 65% of the diseased ears in patients. The mean volume of the mastoid air cell system in Meniere patients, determined at operation, was 5.3 ml.

Adolescent↗
PubMedDate not supplied

The clinical picture of Meniere's disease in the light of glycerin and urea tests.

A mathematical-statistical analysis of the role of glycerin and urea tests in patients with Meniere's disease is presented. Using the quantification method for multidimensional qualitative data, 13 variables were analysed. The younger the patient the stronger was the correlation between age and positive glycerin and urea tests. At ages over 50 years, no correlation to positive test results was found. The longer the duration of disease, the stronger was the correlation between this duration and a positive urea test. The glycerin test showed no correlation to the duration of the disease. Hearing losses of 40-69 dB were correlated both to a positive glycerin test and to a positive urea test. Greater hearing losses were correlated only to a positive glycerin test. Hearing losses of less than 39 dB were not correlated to positive results of either the glycerin or the urea test. Directional preponderance in the caloric test showed a correlation to a positive urea test. On the basis of these results a hypothesis has been formulated to explain how glycerin and urea might affect the internal ear.

Adult↗
PubMedDate not supplied

Meniere's disease in Uppsala and Osaka. A comparative study.

A total of 100 patients with Meniere's disease, 50 at the University Hospital of Uppsala and 50 at the Osaka City University Hospital, were submitted to a test battery using the same methods, and the results obtained at the two hospitals were compared. Briefly the findings were as follows. There was no significant difference in age at examination or in the duration of illness. No significant difference was detected with regard to a) the average hearing loss or the types of audiogram, b) the incidence of spontaneous or positional nystagmus, or c) caloric and optokinetic test results. A linear correlation was found between caloric responses and pure tone audiograms in both the Uppsala and Osaka patients.

Audiometry, Pure-Tone↗
PubMedDate not supplied

Controversies on the caloric response. From Bárány's theory to studies in microgravity.

Two objections against Robert Bárány's scientific contributions are reviewed. Firstly the Medical Faculty in Vienna raised the question as to whether Bárány really could be credited with the initial discovery of the caloric reaction in man and whether therefore it was justified to have awarded him the Nobel Prize in 1914. The second objection consists in strong doubt as to the correctness of Bárány's theory that changes in the temperature of the irrigation water result in density changes in the endolymph, permitting the fluid to be acted upon by gravity, yielding convection currents. Four arguments against Bárány's theory have been put forward: that (1) a caloric response can be elicited from "dead" ears, (2) the two points of reversal of the caloric response from right- to left-beating do not lie 180 degrees apart, (3) the duration of the caloric response, to both cold and warm stimuli, is greater in the face-up than in the face-down position, and (4) caloric nystagmus can also be evoked in a weightless environment. Conclusions based on results of caloric tests in microgravity have been criticised. It is not possible today to dismiss Bárány's theory as incorrect on scientific grounds. On the contrary, there is evidence for the occurrence of both thermal convective currents and a simultaneous non-convective thermal mechanism, acting together in the caloric response.

Austria↗