Download Produced: May 2006 - Lancashire Teaching Hospitals

With acknowledgment to Karen Morrison, Professor of
Neurology, Head of the Department of Clinical Neurosciences,
Honorary Consultant Neurologist, Institute of Biomedical
Research, The Medical School, University of Birmingham.
Lancashire Teaching Hospitals
NHS Foundation Trust
Neuro muscular Nurse Specialist 01772 523412
Sources of further information:
www.lancsteachinghospitals.nhs.uk
www.nhsdirect.nhs.uk
www.patient.co.uk
Lancashire Teaching Hospitals NHS Foundation Trust is
not responsible for the content of external internet sites.
English
BENIGN
FASCICULATIONS
Information for patients
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Neurology
Neurosciences Directorate
Produced: October 2009
Review: October 2012
What is benign fasciculation syndrome (BFS)?
What is the cause?
Fasciculations are spontaneous, irregular, involuntary and
painless brief twitches in a muscle. They may generate concern
because of their known association with motor neurone disease
(MND), although they are an uncommon presenting symptom of
this condition. Studies of people with BFS, followed in some
cases for over 30 years, show that none of them went on to
develop MND or any other serious neurological disorder.
The cause is unknown. The fasciculations represent
spontaneous contractions of muscle fibres in a small part of a
muscle and are thought to arise due to overexcitability in the
nerve fibre.
Most healthy people notice occasional fasciculations. Some will
experience these more frequently than others. Diagnosis of
benign fasciculation syndrome (BFS) is appropriate when
individuals have prominent, frequent fasciculations occurring
over months or years. Fasiculations may occur in any muscle but
seem especially common in the eyelids, calves and other leg
muscles.
They may be provoked by stress, fatigue, exercise, alcohol or
caffeine. Some drugs, including beta-agonists (used for asthma),
D-penicillamine and levothyroxine therapy have also been
associated with fasciculations.
Sufferers may have minor cramping, tingling, muscle pain or
fatigue in addition to painless fasciculations. Neurological
examination is normal, with no reduction in muscle strength.
Neurophysiological examination (if required) reveals
fasciculations on needle electromyography, with no other
abnormalities.
One study reported an increased incidence of respiratory or
gastrointestinal infection in the month before onset of
fasciculations, suggesting that an immune response to such
infection might result in nerve changes and fasciculations.
Does it resolve or is there treatment?
There is no treatment to reduce the fasciculations and
reassurance that they are not sinister is usually the only therapy
required. Awareness of fasiculations often comes and goes
over time, and in some patients they may go away.