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Biomedical subjects

K Ritter

Publications and source records attributed to K Ritter.

At least 73 records · Page 4Linked to original sources
PubMed1983

EEG longitudinal studies in febrile convulsions. Genetic aspects.

It was the purpose of the study to obtain viewpoints on the genetics of febrile convulsions and their relationship to epilepsy by EEG long term follow up. 89 children with febrile convulsions could be followed up to the age of 11 to 13 years (in total 1046 EEG records). The study was concentrated on genetically determined EEG patterns: bilaterally synchronous spikes and waves, photosensitivity and 4-7 cps rhythms. The statistical evaluation was based on standards derived from known strict age dependence of the different patterns. Theta rhythms were found in 54%, spikes and waves of the resting record in 49% and photosensitivity in 42%. In total, genetically determined EEG patterns were found in 81% of the cases which were sufficiently investigated according to given standards. Spikes and waves are strongly age dependent with a maximum at the age of 5-6 years and appear very inconstantly. Theta rhythms and spikes and waves are closely correlated. Spikes and waves are a heterogeneous phenomenon. The type described here must be interpreted as a facultative symptom of the same functional anomaly which forms the basis of 4-7 cps rhythms. The possible pathophysiological basis of the pattern is discussed.--Photosensitivity is interpreted as the symptom of a genetically independent pathogenetic mechanism, which can lead to additive effects by interaction with other genetic abnormalities as well as exogenous factors.--The pathogenesis of febrile convulsions is multifactorial in the strict sense. While the exogenous pathogenetic factors are rather uniform, the genetic predisposition apparently is not. It is based on different genetic anomalies. Each of them is polygenically determined. In the individual case one or different factors can be involved. The genetic predisposition to febrile convulsions is definitely not only polygenic, but of heterogeneous nature. Finally the genetic relationship between febrile convulsions and epilepsy is discussed.

Adolescent↗
PubMed1979

[Tullio-phenomenon (author's transl)].

Applying sound waves to one ear, reflectory head- and bodymovements as well as nystagmus and vertigo are produced. We could study a Tullio-Phenomenon in a patient with a latero-basal fracture of the skull, who showed an otoliquorrhia from the medial wall of the tympanon. After surgical procedure the Tullio-Phenomenon could no longer be achieved.

Acoustic Stimulation↗
PubMed1978

[The vessels of the inner ear (author's transl)].

The inner ear as an example of a highly specialized sensory organ also possesses a highly specialized vascularisation. This represents an impressive example for a reasonable adaption of the terminal blood vessels to a specific function of the organ fulfilling more than only the nutrition. In this paper the microvascular bed of the cochlea is examined using both the injection method of the vessels and the biomicroscopic observation in vivo. The combination of these technics supported by histologic and stereoscan microscopic examinations has made it possible to give an account of the functional morphology of the inner ear vessels. As a detailed structural analysis of the vessels morphology with the help of dyes that fill the whole of the vessels space (i.e. Berlin blue) is not possible, perfusion experiments with silver nitrate were performed on the inner ear. After the perfusion the vessels are cleaned again, the silver however imbibes the intercellular reticular substances and after exposure produces a continous and sharp framework of the endothelium and--when present--muscular cells, thus showing the angioarchitectural contours. There is a very clear division of the cochlear vessels in a three dimensional space: The arterial and venous vessels are vividly separated from one another, forming two systems of microvascular units in the lateral wall and the spiral lamina. Each unit begins with special blood vessel convoluts in the modiolus, consisting of loops of arterioles. They are weakly muscularized whereas no muscle structures are seen elsewhere in the other parts of the inner ear vessels. There are no a.-v. anastomoses or sphinkters at all. The function of the vessel loops in the modiolus is to flatten the pulse wave as well as to regulate the blood flow in the microvascular bed by vasomotion. This was proved by statistical examinations of 1200 measurements of the widths of the vessels at several points of the cochlea in a blind study with and without vasoactive drugs. The terminology of the vessels is not standardized. The nomenclature in this paper has regard to the classification of the vessels, the course and the topographic localisation. Silver staining reveals changes in the form of the endothelium cells from the arterial towards the venous end. While the arteries show a long stretched spinle or lancet like form they change over blunt, oval, triangular or rhomboid forms into polygonal cells with spiked border lines at the venules. All experiments together give an account that the blood supply of the inner ear is in close correlation with the blood supply of the brain and too possesses autoregulative mechanisms, which must be localized in the convoluts at the beginning of every microvascular unit of the cochlear vessels.

Arterioles↗
PubMed1977

[The apoplexy of the labyrinth (author's transl)].

Owing to the morphological, physiological and pathophysiological similarities in the vasculature of the brain and the inner ear, the term apoplexy can also be applied to the inner ear. The apoplexy of the labyrinth is defined as an acute and severe panlabyrinthic disturbance with sudden hearing loss or deafness in association with vestibular functional disorders. The apoplexy may occur after hemorrhage as a result of inner ear blood vessel ruptures or after malacias following localised ischemias just as it occurs in the brain. Treatment of such cases were carried out by application of high doses of cortison. The prognosis of these inner ear disturbances is unfavourable.

Animals↗
PubMed1976

[Pantopaque cisternography in diagnosis of acustic neuromas (author's transl)].

In 6 out of 37 patients, examined by pantopaque cisternography the suspect of a acustic neuroma could be strengthened. All of these tumors showed growth beyond the internal auditory meatus. Smaller intrameatal tumors were not found. The indication for cisternography were made almost according to the demands from Fisch and Wegmüller, therefore it is asked, wether it should not be better to follow the methods of Valvassori who sometimes performes cisternography based on audiometric findings alone. As results of our own experience and similar cases reported elsewhere, this seems justified. Because of the small amount of contrast medium used the side-effects of Pantopaque-cisternography are practically nil.

Contrast Media↗
PubMed1975

[Headache and dependence on mixed analgesic preparations].

Six cases out of 38 women patients with persistent headache and abuse of analgesics are described in more detail. From the observations, inferences are drawn for a more specific and critical prescription of analgesics. The continuous taking of commercially available mixed preparations implicates among other risks the danger of the development or deterioration of chronic headaches. The main cause for the dependence is the barbiturate portion which is a common feature of the drugs taken.

Adult↗