Laryngeal pacemaker: activity of the posterior cricoarytenoid muscle (PCM) and the diaphragm during respiration in sheep.

Electromyograms (EMG) of the PCM and the diaphragm were evaluated in 6 sedated female sheep. Corresponding pneumatograms were recorded simultaneously by means of thermocontrolled respiration flowmeter. Evidence was obtained on considerable intra- and inter-individual differences in the duration of respiratory cycles as well as PCM- and diaphragmatic activity. Most of the evaluated respiratory periods showed either a phase coincidence between the PCM and the diaphragm, or a leading edge of about 40-80 ms of the posticus muscle. Due to this minimal phase shift, the diaphragmatic myogram seems to be a valuable trigger for an external PCM stimulation unit in bilateral recurrent nerve palsy.

Comparative histochemistry of human and sheep laryngeal muscles.

Four laryngeal muscles of human male, human female and sheep female cadavers were evaluated by histological, histochemical and quantitative techniques. The muscle fibre sizes showed significant differences between human male, female and sheep. Fibre diameters of male human laryngeal muscles were 2 to 4 microns larger than in female human and 11 to 13 microns larger than in sheep muscles. In the group of human laryngeal muscles, the posterior cricoarytenoid muscle contained the highest percentage (65%) of type I fibres. In sheep, the homologous muscle consists only of 45% type I fibres. On the other hand, in sheep the cricothyroid muscle showed significantly more type I fibres (58%) than the human counterpart (43%). In both species the vocal muscles had a rather low content of type I fibres (26 to 37%).

Isomyosin changes after functional electrostimulation of denervated sheep muscle.

Isomyosin analyses by biochemical, immunochemical, and histochemical investigations have been carried out in five sheep following unilateral recurrent laryngeal nerve paralysis and direct functional electrostimulation of the denervated cricoarytenoid posterior muscle. Myosin light chains were identified by two-dimensional gel electrophoresis. Myosin heavy chains were analyzed by one-dimensional SDS-polyacrylamide gel electrophoresis. Slow myosin heavy chain was identified by orthogonal peptide mapping and immunochemistry. The stimulation effect at cellular level was determined using adenosine triphosphatase (ATPase) histochemistry. A dramatic increase of the type 1 fiber area (slow, fatigue-resistant fibers) could be seen after many weeks of an increasing regime of low-frequency direct electrical stimulation. Biochemically, the amount of slow myosin was always higher than in normal muscles. Some muscles were transformed almost completely to the slow type. At the time they were studied and with the methods employed, the expression of embryonic isomyosin was not observed. In conclusion, after numerous weeks of maintained functional activity, elicited by direct electrostimulation, the denervated muscle regionally showed areas of hypertrophy or at least lack of atrophy of slow myofibers without major signs of muscle damage.

Comparative anatomy of human and sheep laryngeal skeleton.

In a macroscopical study the dimensions of the adult laryngeal skeleton of man and sheep were compared. In both species the data for male and female were evaluated separately. In contrast to pronounced differences in size between male and female human larynges, the dimensions of both sexes in sheep proved to be very similar. In respect of 7 size values, the sheep larynx falls in the range between the male and female human larynx. This applies to most values for height, the antero-posterior diameter and the inferior breadth of the thyroid cartilage. In the sheep cricoid, the height of the lamina and the inner transverse diameter correspond closely to the human counterpart. The most conspicuous differences vis-à-vis the human larynx are the narrowing of the upper portion, the absent upper incisure of the thyroid and the relatively large dimensions of the arytenoid cartilages in sheep. Since in sheep the dimensions at the level of the glottis and of the subglottic space are within the range of the human larynx, the suitability of the sheep larynx as a model for experimental clinical laryngology is discussed.

[Differences in the neuromuscular blockade of the larynx and thenar muscles following relaxation with vecuronium]. / Unterschiede in der neuromuskulären Blockade der Kehlkopf- und Thenarmuskulatur nach Relaxation mit Vecuronium.

To objectivate the clinical impression of different neuromuscular depression in the larynx- and limb-musculature, an attempt was made in 5 patients to quantify laryngeal muscle relaxation by electromyographic recordings of evoked responses from the vocalis muscle during endolaryngeal microsurgery. Mechanographic and evoked electromyographic recordings of the thenar muscles were obtained simultaneously. Nearly total suppression of evoked responses at the peripheral muscle site was observed after a bolus dose of either 60 micrograms/kg or 100 micrograms/kg of the nondepolarising muscle relaxant Vecuronium. However, the vocalis muscle was not blocked completely. The neuromuscular depression ranged from 61 to 92% depending on the dose. In no case was the recommended intubating dose (ED 95) of 60 micrograms/kg sufficient for complete relaxation of the vocalis muscle. The present results do not support that the extent and/or time course of intrinsic laryngeal muscle relaxation correlates with peripheral neuromuscular depression in a quantitative manner. The different degree of relaxation achieved by Vecuronium in the hand and larynx is probably due to their different content of acetylcholine receptors.

[The pharmacodynamics of vecuronium on the musculature of the vocal cords and the ball of the thumb. Preliminary report]. / Zur Pharmakodynamik von Vecuronium an Stimmband- und Thenarmuskulatur. Vorläufige Mitteilung.

During endolaryngeal microsurgery, an attempt was made to quantify laryngeal muscle relaxation by electromyographic recording of evoked responses from the vocal cord musculature in 5 patients. Both mechanographic and electromyographic recordings from the adductor pollicis were obtained simultaneously. Following a bolus dose of vecuronium (60 micrograms/kg, n = 3, and 100 micrograms/kg, n = 2), nearly total (97%-100%) suppression of evoked responses at the peripheral muscle site was observed; the vocal cords, however, did not show complete neuromuscular (nm) blockade, but rather varying degrees of nm depression ranging from 61%-92%. The present results clearly show that quantitative information as to duration and degree of neuromuscular depression in the vocal musculature may be obtained by electromyographic recordings of evoked potentials in the clinical setting; it is impossible however, to quantitatively estimate the extent of intrinsic laryngeal muscle relaxation from peripheral nm depression. The pharmacodynamic differences observed might be due to the varying acetylcholine receptor density of the muscle groups studied.

[Evaluation of real-time sonography in the pretherapeutic staging of malignant tumors of the tongue and mouth floor]. / Bewertung der Real-time-Sonographie im prätherapeutischen Staging maligner Zungen- und Mundbodentumoren.

Based on our three years experience with about 200 transcutaneous real-time sonographies of the tongue and the floor of mouth, an assessment of the determination of size and site of 38 pretherapeutically examined malignant tumours (35 squamous cell carcinomas) was made. The patients were examined in reclined position, the head retroflected. Curved array transducers of 5 or 7.5 MHz and a silicon elastomer block as interface turned out to be optimal. All tumours could be detected by sonography as hypoechoic, more or less homogeneous, ill-defined areas. Two thirds of the tumour ulcerations could be seen as hard hyperechoic reflexes within the hypoechoic areas. When comparing the maximal diameter of tumours of the 20 operated patients, we found an agreement (5 mm tolerance) of sonography with the surgical specimen in 14 of 20 tumours (70%), of sonography with the clinically estimated diameter in 10 of 20 tumours (50%), whereas the clinically estimated diameter was in agreement with the surgical specimen in only 8 of 20 tumours (40%). A peritumoral inflammatory infiltration can simulate a larger tumour size in sonography. The extent of tumours within the tongue, to the floor of mouth, the lateral pharyngeal wall and the preepiglottic space was documented correctly in most cases. In three cases a previously unknown spread across the midline was found sonographically. Including the sonographic findings in the TNM classification, 5 T1 tumours would have been staged as T2 and one T3 tumour as T4. Inflammatory diseases of the tongue can show the same sonomorphology as malignant tumours.

[Central localization of motor components in the internal branch of the superior laryngeal nerve: a horseradish peroxidase study in the rat]. / Zentrale Lokalisation motorischer Komponenten im Ramus internus des N. laryngeus superior: Eine HRP-Studie bei der Ratte.

The central organisation of the internal branch of the superior laryngeal nerve was examined in the rat using the technique of intraaxonal transport of horseradish peroxidase (HRP). Application of HRP to the internal branch resulted in anterograde labelling of afferent nerve fibres as well as in retrograde labelling of perikarya within both motor nuclei of the vagus, i.e. the nucleus ambiguus and the dorsal motor nucleus. The location of retrogradely labelled neurons is confined to an area of 700 microns length near the rostral extremities of both nuclei. The internal laryngeal branch, therefore, is not entirely sensory, but contains general and special visceral efferent fibres arising in the dorsal motor nucleus and in the nucleus ambiguus, respectively. Dorsal motor neurons of the internal branch represent preganglionic parasympathetic neurons projecting to the mucous glands of the larynx, whereas efferents from the nucleus ambiguus supply striated muscle fibres of the larynx. The arytenoid and aryepiglotticus are discussed as potential targets of the internal branch of the superior laryngeal nerve.

[Functional electrostimulation of the denervated posticus muscle in an animal experiment: histo- and biochemical results]. / Funktionelle Elektrostimulation des denervierten M. posticus im Tierversuch: Histo- und biochemische Ergebnisse.

Histochemical and biochemical investigations have been carried out in 2 sheep following unilateral recurrent laryngeal nerve paralysis and direct electrical stimulation of the denervated posticus muscles. The stimulation effect was determined histochemically (standard ATP-ase staining) and compared with the fibre pattern of normal posticus muscles. In addition, one-dimensional gel electrophoresis of myosin heavy-chain isoforms was carried out and correlated with the histochemical results. A dramatic increase of type I fibres could be seen after long-term low-frequency direct electrical stimulation of denervated posticus muscles of the sheep. Biochemically the amount of slow myosin heavy-chain isoforms was higher than in normal muscles.

[A method for puncturing the deep neck muscles in humans]. / Methodik zur Punktion der tiefen Nackenmuskulatur des Menschen.

The authors developed a method to puncture neck muscles by means of computer tomographic control, enabling the introduction of an electrode into the obliquus capitis inferior muscle, to investigate the particular role of neck muscles in posture and head movement.

Horseradish peroxidase histochemistry on mounted sections from embedded specimen: a simple method for serial reconstruction of neuronal projections.

A combination of two procedures, embedding of specimens and horseradish peroxidase (HRP) histochemistry on mounted serial sections, is proposed for three-dimensional reconstruction of neuronal projections. To clarify the intrinsic organization of the peripheral nervous system, this simple method is more adequate than previously used techniques.

[Acute loss of vestibular function: an emergency for patient and physician]. / Der akute periphere Vestibularisausfall: Ein Notfall für Patient und Arzt.

The dramatic symptomatology of sudden loss of vestibular function alarms the patient and the physician who is consulted in an emergency situation. The continuous vertigo is often accompanied by marked autonomic symptomatology, so that heart and cerebral diseases as well as acute intoxication are often primarily diagnosed. The differential diagnosis, clinical features, course of the disease and treatment are presented in this study of 54 patients treated in our department between 1980 and 1985. Aetiology and pathogenesis are discussed on the basis of the literature.

[Angiolymphoid hyperplasia with eosinophilia (Kimura disease)]. / Angiolymphoide Hyperplasie mit Eosinophilie (Kimura's Disease).

A case of a rare disease, known as angiolymphoid hyperplasia with eosinophilia, or Kimura's disease, is described in order to discuss the histopathology, aetiology and differential diagnosis by means of literature. The clinical symptomatology consisting of the appearance of cutaneous or subcutaneous tumours is reported as well as the histological features. The therapy of choice is the surgical treatment of the tumour, whereas in most cases radiation or large-dosed therapy with corticosteroids leads to remissions only.