The motor unit in muscular dystrophy, a single fibre EMG and scanning EMG study.

Hilton-Brown, P; Stålberg, Erik

doi:10.1136/jnnp.46.11.981

Cited by 48 publications

(21 citation statements)

References 20 publications

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“…These results agree with previous findings in patients suffering from muscular dystrophy. The muscles of these patients showed no difference in the length of motor unit cross-sections but showed an increased number of silent areas and an increased variability in the amplitude profile and shape of scanning EMG recordings (Hilton-Brown & Stålberg, 1983a. Myopathic processes cause several structural changes, including fibre loss, fibre atrophy and hypertrophy, and fibre splitting (Hilton-Brown & Stålberg 1983a).…”

Section: Findings In Pathological Conditionsmentioning

confidence: 98%

“…The length of the motor unit cross-section (Hilton-Brown & Stålberg, 1983aStålberg, 1986) is defined as the maximal distance between traces with amplitudes of at least 50 μV (Fig. 7).…”

Section: Length Of the Motor Unit Cross-sectionmentioning

confidence: 99%

“…A limited number of muscle types has been investigated using scanning EMG, including the biceps brachii (Hilton-Brown & Stålberg, 1983aStålberg & Diószeghy, 1991; Navallas Stålberg, 2009), the tibialis anterior (Hilton-Brown & Stålberg, 1983aStålberg & Diószeghy, 1991), the masseter (Stålberg & Eriksson, 1987), and the quadriceps (Gootzen, 1990;Gootzen et al, 1992). The length of the motor unit cross-section has been measured in normal conditions in various muscles.…”

Section: Findings In Normal Conditionsmentioning

confidence: 99%

“…The length of the motor unit cross-section has been measured in normal conditions in various muscles. In the biceps brachii, the length of the motor unit cross-section has been reported as 6.0 ± 3.9 mm (mean ± SD) (Hilton-Brown & Stålberg, 1983a, 4.64 ± 2.14 mm with a range of 1.69 to 10.17 mm (n=59) (Stålberg & Diószeghy, 1991), and 4.39 ± 2.29 mm with a range of 1.55 to 10.70 mm (Navallas & Stålberg, 2009). In the tibial anterior, the length has been reported as 7.9 ± 1.3 mm (Hilton-Brown & Stålberg, 1983a) and 5.26 ± 2.18 mm with a range of 1.53 to 10.33 mm (n=70) (Stålberg & Diószeghy, 1991).…”

Section: Findings In Normal Conditionsmentioning

confidence: 99%

“…In the biceps brachii, the length of the motor unit cross-section has been reported as 6.0 ± 3.9 mm (mean ± SD) (Hilton-Brown & Stålberg, 1983a, 4.64 ± 2.14 mm with a range of 1.69 to 10.17 mm (n=59) (Stålberg & Diószeghy, 1991), and 4.39 ± 2.29 mm with a range of 1.55 to 10.70 mm (Navallas & Stålberg, 2009). In the tibial anterior, the length has been reported as 7.9 ± 1.3 mm (Hilton-Brown & Stålberg, 1983a) and 5.26 ± 2.18 mm with a range of 1.53 to 10.33 mm (n=70) (Stålberg & Diószeghy, 1991). In the masseter, the length has been reported as 3.7 ± 0.6 mm with a range of 0.6 to 12.5 mm (Stålberg & Eriksson, 1987) and 3.7 ± 2.3 mm with a range of 0.4 to 13.1 mm (Tonndorf et al, 1994b).…”

Section: Findings In Normal Conditionsmentioning

confidence: 99%

See 4 more Smart Citations

Scanning Electromyography

Navallas¹,

Rodríguez²,

Stålberg³

2012

EMG Methods for Evaluating Muscle and Nerve Function

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Section: Findings In Pathological Conditionsmentioning

confidence: 98%

“…The length of the motor unit cross-section (Hilton-Brown & Stålberg, 1983aStålberg, 1986) is defined as the maximal distance between traces with amplitudes of at least 50 μV (Fig. 7).…”

Section: Length Of the Motor Unit Cross-sectionmentioning

confidence: 99%

Section: Findings In Normal Conditionsmentioning

confidence: 99%

Section: Findings In Normal Conditionsmentioning

confidence: 99%

Section: Findings In Normal Conditionsmentioning

confidence: 99%

See 3 more Smart Citations

Scanning Electromyography

Navallas¹,

Rodríguez²,

Stålberg³

2012

EMG Methods for Evaluating Muscle and Nerve Function

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Functional magnetic resonance imaging of human motor unit fasciculation in amyotrophic lateral sclerosis

Whittaker

Porcari

Braz

et al. 2019

Annals of Neurology

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A novel diffusion-weighted magnetic resonance imaging protocol sensitive to contraction of individual skeletal motor units was developed. We applied this technique to the lower limb muscles of 4 patients with confirmed amyotrophic lateral sclerosis (ALS) and 6 healthy controls. A 3-minute scan revealed florid fasciculation in ALS patients, involving both superficial and deep muscles, and at a frequency higher than in healthy controls. This novel imaging technique reveals hitherto unobtainable information on human motor unit structure and function, which may allow earlier diagnosis and recruitment to clinical trials.

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Scanning electromyography

Di�szeghy

2002

Muscle Nerve

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A special electromyography (EMG) method, scanning EMG, was introduced by Stålberg and Antoni in 1980 to study the electrophysiological cross sections and sizes of motor units. Scanning EMG gives a new approach for the evaluation of the electrical properties of motor units, providing new data on the normal anatomical distribution of muscle fibers and its changes in different pathologies of the muscle. The description of scanning EMG recordings required the introduction of new parameters (lengths of motor unit cross sections, fractions of motor units, and silent areas), in addition to those used with conventional EMG recordings, and the traditional parameters (duration, amplitude, etc.) acquired new and more accurate explanations. Normal scanning EMG recordings are available for biceps brachii, anterior tibial, and masseter muscles. The findings in normal muscles agree with the nonrandom distribution of muscle fibers in motor units and confirm the suggestion that muscle fibers within motor units tend to be arranged in clusters. In muscular dystrophies, the sizes of motor unit territories do not differ significantly from the normal values. However, the configuration of motor units changes considerably. Abrupt changes in amplitude and duration, segments of short and long duration, increased numbers of fractions, and silent areas have been revealed, showing that dystrophic motor units are definitely fragmented. Scanning EMG supports the assumption that there is clustering of muscle fibers within the dystrophic motor unit, with local grouping of muscle fibers. In neurogenic lesions, the length of motor units is normal or only slightly increased. Reinnervated motor units are restricted to the fascicles in which they are originally found. Reinnervation does not result in an increase in the number of fractions, but the amplitude of the potentials, the length of polyphasic sections, and the duration increase. The increase in the number and length of polyphasic sections can differentiate normal motor units from abnormal ones. However, other features (amplitude, duration, number of fractions, and presence of silent areas) are also necessary to distinguish neurogenic processes from myogenic ones.

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The motor unit in muscular dystrophy, a single fibre EMG and scanning EMG study.

Cited by 48 publications

References 20 publications

Scanning Electromyography

Scanning Electromyography

Functional magnetic resonance imaging of human motor unit fasciculation in amyotrophic lateral sclerosis

Scanning electromyography

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