Benign fasciculation syndrome (BFS) is characterized by fasciculation (twitching) of voluntary muscles in the body. The twitching can occur in any voluntary muscle group but is most common in the eyelids, arms, hands, fingers, legs, and feet. The tongue can also be affected. The twitching may be occasional to continuous.
Other common symptoms are generalized fatigue or weakness, paraesthesia or numbness, and muscle cramping or spasms. BFS is reportedly found among "anxious medical students" and clinicians under the age of 40,
Diagnosis
Benign fasciculation syndrome is a diagnosis of exclusion; that is, other potential causes for the twitching must be ruled out before BFS can be diagnosed. Diagnosis includes blood tests, a neurological exam, and electromyography (EMG). Other publications recommend followups for four or five years before ruling the condition benign, although the percentage of individuals who progress to a more serious condition is very low. and spinal cord diseases. It is "exceptionally rare for patients later diagnosed with ALS to present with fasciculations alone", and ALS is ruled out with a normal EMG and no evidence of muscle wasting.
Research
There may be an association between widespread fasciculations or paresthesias with small fiber neuropathy.
A 2017 study in Neurology also found that benign fasciculations are common in the general population, occurring in about 70% of healthy individuals and almost never associated with a serious neuromuscular disorder. Of patients that enrolled in a 1, 3, 6, 12 and 24 month study, perceived weakness was reported in 35.3%, 47.1% experienced numbness, 70.6% had tingling, cramps were present in 64.7% and after 24 months, only 5% had their symptoms resolved. Of all the patients, none developed motor neuron disease.