Abstract
Patients with autosomal recessive generalized myotonia, or Becker's disease, often suffer from a peculiar transient paresis. As yet, the relationship between this transient paresis and the defect in the gene encoding for a voltage gated Cl- channel protein in the muscle membrane of these patients is unclear. In order to gain a better understanding of the electrophysiological properties of the muscle fibre membrane in these generalized myotonia patients, we have studied transient paresis with a novel high-density surface EMG (sEMG) technique. We conclude that the transient paresis is explained by a deteriorating muscle membrane function, ending in conduction block and paresis. Multi-channel sEMG during the period of force decline in transient paresis shows a decrease in peak-peak amplitude of the motor unit action potentials from endplate towards tendon. This disturbance increases with time and place, indicating a deteriorating membrane function, and ends in a complete blocking of propagation within seconds. Spatiotemporally, this leads to a V-shaped sEMG pattern. In a more general sense, this contribution shows how spatiotemporal information, available through non-invasive high-density sEMG, may provide novel insights into electrophysiological aspects of membrane dysfunction.
Original language | English |
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Pages (from-to) | 352-360 |
Number of pages | 9 |
Journal | Brain |
Volume | 124 |
Issue number | Pt 2 |
DOIs | |
Publication status | Published - Feb 2001 |
Externally published | Yes |
Keywords
- Action Potentials
- Adult
- Electromyography/instrumentation
- Female
- Genes, Recessive
- Humans
- Male
- Middle Aged
- Motor Endplate/physiopathology
- Muscle Contraction
- Muscle Fibers, Skeletal
- Myotonia Congenita/complications
- Paresis/etiology
- Stress, Mechanical