Surface EMG-recordings using a miniaturised matrix electrode: a new technique for small animals.

A new method for multichannel surface-EMG measurements in small animals is presented. The underlying scientific aim is the characterisation of the spreading and the co-ordination of skeletal muscle activation between different muscles or muscle parts, depending on various motor tasks. The myoelectrical signals were recorded monopolarly by a 16-channel matrix electrode on the muscle surface directly under the skin on the fascia of the investigated muscle, without damaging the muscle. Surface-EMG's were recorded for at least 5 days after surgery without electrical interferences. During defined motor tasks, the projection of the myoelectrical activation of the different parts of the M. triceps brachii of rats (Rattus norvegicus), pikas (Ochotona rufescens) and cuis (Galea musteloides) or the M. anconeus of toads (Bufo marinus) on the muscle surface was mapped. The locomotion of the investigated animals was monitored by a three-dimensional kinematic analysis (video and/or high-speed cineradiography). There was no perceptible influence from application of EMG matrix electrode. The miniaturised matrix electrode seemed practicable in gaining insight into changes in myoelectrical activation patterns (EMG mapping). This allows a characterisation of the intramuscular co-ordination processes corresponding to the actual morphofunctional state of the investigated animals.

Pathogenesis of dysplasias of the face and the ear and dystopias of the temporal region.

Dysplasias of the face and ear are supposed to be caused by a premature involution of 3 different embryonal arteries of the branchial arches: (1) Dysfunction of the mandibular artery causes the otocephalia syndrome; (2) that of the stapedial artery causes dysplasias of the face; (3) dysfunction of the hyoid artery entails dysplasias of the ear; and (4) combination of (2) and (3) (dysfunction of truncus hyostapedialis) results in simultaneous dysplasias of the face and the ear. The earlier the deficiency of blood supply occurs the more serious the resulting dysplasias are. The dystopias in the temporal region (auricles, facial nerve, ossicles, petrous bone) are the consequence of an overbending of the proximal hyoid arch caused by a retardation in the development (shortening) of the mandibular arch. Therefore, dystopias of the ear always occur together with dysplasias of the face. Phenotype and appearance on radiographs are discussed.

A new concept for reconstruction of atresias of larynx and trachea: lining of wound surfaces with autologous isolated respiratory epithelial cells.

A new method, first applied two years ago in our clinic, has proved to be reliable for achieving a rapid reepithelialisation of epithelial defects after scar removal inside the trachea. The defect is seeded with isolated respiratory epithelial cells harvested the day before from the ethmoid. Isolation of epithelial cells was achieved by keeping the mucosa in 0.25% trypsin buffer solution under room temperature for about 16 h. Afterwards, the epithelial layer was separated from the submucosa using small forceps and knife. Cells were then isolated by pipetting. For seeding the wound the surface was covered with silastic sheeting and the cell suspension then injected into the cleft between both of them. Cell distribution occurred by capillary attraction. The tracheal lumen was maintained by inserting a silastic stent for about three weeks. So far, 10 patients between 6 and 45 years have been treated in this way. In 4 patients the tracheal wall additionally had to be stabilized using rip cartilage. Only in one case above the tracheostoma, considerable scar formation occurred again requiring a second operation some months later. In 8 patients decannulation was meanwhile possible.

[Pneumatotomography of the orbit (author's transl)]. / Die Pneumotomographie der Orbita.

After a description of the technique of -examination appropriate to pneumatotomography of the orbit the efficiency of this diagnostic method is discussed with regard to 8 personnally performed examinations. 5 cases are discussed in detail with illustrations. The indication for pneumatotomography should only be given when an orbitotomy is necessary. Serious complications are not known. Temporary increase of exophthalmos with emphysema of the eyelids, however, definitely uncomfortable for the patient.

[Examination to possibilities of a physiological fitting of cochlear implants]. / Untersuchungen zu Möglichkeiten einer physiologischen Anpassung von Cochlea-Implantaten.

BACKGROUND: Cochlear implants (CI) convert acoustic events into electrical pulses. The auditory nerve picks these tiny electrical pulses up and sends them to the brain. The dynamics of the audible sound is compressed considerably. The limits for stimulation are determined with the patient. A map law determines which sound pressure level is assigned to which stimulation level. A sufficient speech understanding requests an allocation of high stimulation levels for weak sound signals. The higher the sound level, the lower the increase. Unfortunately, with such kind of map law unwanted background noise is also presented as well audible stimulation. These stimuli are often annoying to CI users in everyday situations. PATIENTS AND METHOD: The possibility to give an s-shaped course to these map laws was examined in 9 patients. After the fitting procedure their speech understanding were tested. The results were compared with the results of former tests. RESULTS: 8 patients reported definite improvement of their hearing situation. Such map laws seem, therefore, suitable to optimise speech processor programming.

[Osteomyelitis of the temporomaxillary joint (author's transl)]. / Die Osteomyelitis des Kiefergelenkes.

Although osteomyelitis of the inferior maxilla is still relatively frequently diagnosed, manifestation of the disease in the temporomaxillary joint is a rare occurrence. The symptomatology, diagnosis, and therapy of this particular arthropathy is discussed by reference to three cases treated in recent years at the Berlin Clinic of Maxillofacial Surgery. The importance of an early diagnosis and therapy is directed attention to because of the danger of serious subsequent diseases that may result in the loss of vital functions.

[Therapy problems in sphenoethmoidal meningoceles]. / Zur Therapieproblematik bei sphenoethmoidalen Meningozelen.

After a brief survey of the forms of cranial meningoencephaloceles, the current opinions on their development, symptoms and surgical therapy, a report is given on the case of a five-year-old boy suffering from a sphenoethmoidal meningocele of the size 3 x 3 x 4 cm. There was at the same time a wide median palate cleft, obviously a consequence of the meningoencephalocele. A further finding presented by the boy was a neuroradiologically diagnosed agenesis of the Corpus callosum and a median cheiloschisis. This suggests a central development disturbance as a primary cause. The attempt to perform an intracranial occlusion of the defect of the base, which was repeated twice, was not successful. It was only by a transpalatinal-transnasal extradural intervention (reposition of the meningocele after removing the epipharyngeal mucosa, blocking of the bony defect with a perforated tantalum plate) that the removal of the meningocele was successful. The closure of the palate cleft was then made by the oral surgeon. This surgical intervention may also be considered for the treatment of the transsphenoidal meningoencephalocele, which also presents many problems.

[Results after surgical therapy of temporomandibular joint ankylosis]. / Behandlungsergebnisse nach operativer Therapie der Kiefergelenkankylose.

This paper reports the results of, and experience gained from, seventy-nine operations for ankylosis performed between 1946 and 1974 at the Berlin Clinic of Maxillofacial Surgery. In fourteen surgical operations freeze-dried dura was used as an implant, with good functional results being obtained.

[Indications for a new joint-bridging miniature external fixator in primary and secondary management of complex hand injuries]. / Indikationen für einen neuen gelenküberschreitenden Minifixateur externe in der Primär- und Sekundärversorgung komplexer Handverletzungen.

25 patients with injuries of the hand were treated by a new external minifixator. A specific joint bridging construction makes it possible to treat severe joint fractures by ligamentotaxis. Another indication is the preoperative continuous elongation treatment in severe contractures of the fingers. The minifixator can be made dynamic and can also be used for interfragmental compression or distraction.

Spatiotemporal surface EMG characteristics from rat triceps brachii muscle during treadmill locomotion indicate selective recruitment of functionally distinct muscle regions.

Multichannel surface EMG recordings of a multiheaded skeletal muscle during cyclic locomotion combined with cineradiography were analysed in a chronic experiment. The resulting detailed two-dimensional activation pattern from the long and lateral triceps brachii heads of the rat during treadmill locomotion were combined with gait characteristics and fibre typing of the muscle. Shortly before ground contact of the forelimb, maximum muscle activity was found in the proximal part of the long head of the muscle. During the stance phase maximum activity was observed in the proximal part of the lateral head. The frequency dependent behaviour of cross-covariance functions over both muscle heads confirmed this selective shift in activation. In the lateral triceps brachii head of the investigated rats, exclusively type II fibres were found. In the long head the frequency of type I fibres was the highest in the deep muscle layers, proximally more than distally, whereas type II fibres were dominant in more superficial muscle layers. A combination of physiological and histological findings supports an anticipating mechanism whereby fine-tuning of the vertical foot down manoeuvre is mainly achieved by the (type I fibre dominated) proximal deep compartment of the biarticular long triceps brachii head and force generation is predominantly executed by the monoarticular lateral triceps brachii head.