Myasthenia gravis: further electrophysiological and ultrastructural analysis of transmission failure in the mouse passive transfer model.

Using the mouse passive transfer model the mean amplitude of miniature endplate potentials and endplate potentials of mice treated with myasthenic immunoglobulins was markedly decreased. Miniature endplate potential frequency and quantum content of endplate potentials were normal, arguing against a major presynaptic disarrangement. Under electron-microscopy no gross structural alterations of endplates were demonstrated. It is concluded that the mouse passive transfer model closely resembles human myasthenia gravis of recent onset.     

Elektrophysiologische Untersuchungen über die Eigenreflex-Erregbarkeit des Menschen bei Vestibularisreizung

Zusammenfassung An 12 normalen Versuchspersonen in Rückenlage wurden vor und nach Vestibularisreizung (einseitige thermische Reizung mit 20 ml Wasser von 20°C) folgende Reflexe des Gastrocnemius geprüft: T-Reflex, H-Reflex, das sogenannte Hemmungsphänomen (Paillard) und der tonisch-myotatische Reflex. Es wurden simultan registriert: Elektronystagmogramm, das Muskel-Aktionspotential und ein Mechanogramm mittels Dehnungsmeßstreifen an der Fußsohle.Es zeigte sich, daß die vestibuläre Reizung eine wesentliche Steigerung der Reflexantwort bewirkt im T-Reflex, dagegen keine eindeutige Steigerung der Reflexantwort im H-Reflex. Zum Zeitpunkt der vestibulären Erregung wurde das Hemmungsphänomen teilweise aufgehoben. Eine Wirkung auf den tonisch-myotatischen Reflex wurde nicht gesehen. Diese Befunde sprechen dafür, daß die labyrinthäre Reizung beim Menschen vorwiegend über das gamma-motorische System die Gastrocnemius-Reflexe beeinflußt, indem sie die Erregbarkeit der Muskelspindeln erhöht.Mit 3 TextabbildungenMit freundlicher Unterstützung der Deutschen Forschungsgemeinschaft.     

Discharge pattern of single motor units in basal ganglia disorders

We studied the discharge pattern of motor units (MUs) from the first dorsal interosseous muscle during slight stationary isometric contraction. In six controls, seven patients with parkinsonism, and five patients with choreic disorders, we analyzed 78 MUs. About one-half of the MUs in both patient groups fired irregularly as shown by interval histograms, joint interval histograms, and corresponding statistical calculations. Cross-correlation techniques revealed a characteristic type of MU synchronization in parkinsonism. Analysis of the MU discharge pattern can be useful in clinical assessment of these disorders.     

Buchbesprechungen

Ohne Zusammenfassung     

Dynamic visual cueing in combination with treadmill training for gait rehabilitation in Parkinson disease

Various cueing techniques as well as treadmill training have been shown to be effective in the gait rehabilitation of patients with Parkinson disease. We present a novel setup combining both dynamic visual cueing and body weight-supported treadmill training. A nonambulatory patient with Parkinson disease received six training sessions. Continuous improvement of gait parameters was observed throughout the course of training. When comparing cued and noncued conditions in individual training sessions, it was found that step length was larger and that gait symmetry was enhanced in the cued condition. At the end of the training period, the patient was capable of walking short distances with a walking frame. In conclusion, dynamic visual cueing in combination with body weight-supported treadmill training seems to be a promising treatment strategy for patients with Parkinson disease, even in the case of severe impairment.     

Disorders of motor unit discharge activity in parkinsonism

The discharge activity of single motor units (MUs) of the first dorsal interosseus muscle was recorded in slight stationary isometric contractions. Normal subjects and patients with parkinsonism of various degrees were investigated. The purpose was to study disturbances of the discharge pattern in the patients and their potential diagnostic role. Automatic signal recognition and statistical analysis of the interval distribution were used. Most MUs of the patients revealed considerable irregularities of their discharge sequences best marked by the so called "floating standard deviation". All patients, also 2 without tremor, showed a characteristic synchronization of their MU discharges ("broad-peak" type). Since the above changes were also seen in the patients with only slight symptoms, these investigations, if methodically simplified, could be of diagnostic value.     

Über die Wirkung des Strophanthins auf den Blutdruck des gesunden Menschen

Naunyn-Schmiedeberg's Archives of Pharmacology -