Biomedical subjects
Publications and source records attributed to M Molcan.
The limitations of the transmeatal phase of the retrosigmoid transmeatal approach are shown, and the problems of opening the internal acoustic meatus via this approach and the criteria for its use are discussed.
The processus supratubalis is a complicated space from the topographical aspect. The author emphasizes the need of careful peroperative examination of the area which may be the site of a residual cholesteatoma. The pathological process at this site may, due to topographic relations with important structures, cause serious functional disorders.
In a topographic investigation the authors assessed on 20 cadaverous temporal bones the relationship between the size of the enlarged recessus facialis and the dimensions of the mastoid process as well as topographic possibilities of a lower medial communication between the trepanation cavity and sinus tympani. Only in two instances the maximal and minimal dimensions of the recessus facialis corresponded to the maximal and minimal dimensions of the mastoid process resp. The possibility to establish a lower medial communication between the trepanation and tympanal cavity depended on the size of the tip of the mastoid process and on the position of the sigmoid sinus and bulbus jugularis resp. in relation to the facial nerve.
The authors compared the autopsy and tomographic findings of meatus acusticus int. In addition to the dimensions of meatus acusticus int. the authors also evaluated its shape and measured the distance between fossa jugularis and lower wall of fundus. The mean values of six parameters observed and measured on the cadavers and the tomograms differed in the following way: three parameters up to 0.5 mm and three by 0.8 mm, 1.1 mm and 1.2 mm, respectively. In eight patients the tomograms were evaluated as pathological; these were described in detail and put into relation to CT, CT-cisternomeatographic or the operation finding.
The authors evaluated the interaction of follow-up eye movements, of the optokinetic nystagmus with the nystagmus of labyrinthine origin. In 15 subjects without data on an impaired vestibular system they observed during a calorically induced nystagmus follow-up eye movements and the optokinetic nystagmus. They confirmed changes of these curves which were closely associated with the direction of the nystagmus. The above changes can be used as one of the criteria for the differentiation of a spontaneous nystagmus of peripheral origin from central nystagmus.
The authors assessed the differences of the limen of interrupted sounds (sounds which last 500 ms, between which there are intervals of 200 ms) in healthy subjects and in patients with sensory neural and supracochlear hearing disorders. Essentially the results are consistent with those of Schorn and Fastl (2) and they suggest that patients with supracochlear hearing disorders are able to differentiate only much greater differences in intensity (more than 4 dB) between sounds, as compared with patients with sensory neural hearing disorders.