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Fasciculation in amyotrophic lateral sclerosis: origin and pathophysiological relevance
Mamede de Carvalho1,2, Matthew C Kiernan3, Michael Swash2,4
1Department of Neurosciences and Mental Health, Hospital de Santa Maria-CHLN, Lisbon, Portugal.
Journal of Neurology, Neurosurgery, and Psychiatry
|May 12, 2017
Summary
Fasciculations, or muscle twitches, can indicate serious neurological conditions like amyotrophic lateral sclerosis (ALS) or benign fasciculation syndromes. Understanding their origin is key to diagnosis and management.
Area of Science:
- Neurology
- Neurophysiology
Background:
- Fasciculations are brief, spontaneous muscle fiber contractions.
- They are observed in various neurological conditions, notably amyotrophic lateral sclerosis (ALS) and benign fasciculation syndromes.
- The precise origin and significance of fasciculations in neurological practice require further elucidation.
Purpose of the Study:
- To review the origin and significance of fasciculations in neurological practice.
- To differentiate fasciculations associated with amyotrophic lateral sclerosis (ALS) from those in benign fasciculation syndromes.
- To explore the evolving sites of fasciculation generation in ALS.
Main Methods:
- Literature review of fasciculations in neurological practice.
- Analysis of the pathophysiology of fasciculations in ALS and benign fasciculation syndromes.
- Distinguishing fasciculations from other neuromuscular phenomena like neuromyotonia.
Main Results:
- Fasciculations originate from ectopic activity in the motor system.
- In early ALS, fasciculations likely stem from proximal motor system sites.
- Later in ALS, distal origins become more prominent, linked to axonal sprouting and reinnervation.
- Fasciculation without other neurological deficits suggests a benign fasciculation syndrome.
Conclusions:
- Fasciculations can be an early indicator of motor neuron dysfunction in ALS.
- Understanding the origin of fasciculations aids in differentiating between ALS and benign conditions.
- Fasciculations are distinct from neuromyotonia, characterized by recurrent axonal firing.
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