[Periods of spontaneous discharges in paretic muscles. Low frequency rhythms of repetitive single, grouped and serial discharges (author's transl)].
Of 1800 patients examined electromyographically, 37 showed different forms of spontaneous low frequency periodical discharges in neuromuscular diseases. Besides the well-known high frequency bizarre discharges of 10-150 per sec in neuropathies and myopathies, low frequency periods of mostly polyphasic potentials are described as "low frequency bizarre discharge". Three types of these rhythms are distinguished: single, grouped, and serial discharges in various peripheral nerve and motor neuron and muscle diseases. The rate of the periods varied from 0.2 to 6 per sec, but was nearly constant in one and the same muscle. The discharge rate within the period may be higher, up to 150 per sec. The low frequency single discharges probably originate in the muscle fibers, the grouped and serial discharges possibly in the terminal branches of peripheral nerves. Rhythmical repetitive discharges may result from a reduction of stimulus threshold and accommodation  of muscle- and nerve fibers respectively. Grouped and serial discharges may also be provoked by nerve stimulation or voluntary innervation.
D000200:Action Potentials; D005071:Evoked Potentials; D006801:Humans; D009132:Muscles / Q000503:physiopathology*; D009135:Muscular Diseases / Q000503:physiopathology; D009408:Nerve Compression Syndromes / Q000503:physiopathology; D009468:Neuromuscular Diseases / Q000503:physiopathology*; D010243:Paralysis / Q000503:physiopathology; D010523:Peripheral Nervous System Diseases / Q000503:physiopathology; D011128:Polyradiculopathy / Q000503:physiopathology; D013997:Time Factors
Periodische Spontanentladungen in paretischen Skelettmuskein. Niederfrequente Rhythmen mit repetitiven Einzel-, Gruppenund Serien-Entladungen