Subject: Re: Another question about twitching
Forum: The Neurology and Neurosurgery Forum
Topic Area: AMYOTROPHIC LATERAL SCLEROSIS - ALS
Posted by CCF Neurology MD:NT on October 25, 1998 at 22:15:09:
In Reply to: Another question about twitching posted by Linda on October 25, 1998 at 19:35:35:

I know this is an overworked subject, yet the idea of ALS is so scary that any help you
could give to clarify these questions would be greatly appreciated. Many thanks in advance.

Dear Linda:

Fasciculations are a form of spontaneous muscle contraction which involves small groups of muscle fibers sporadically and irregularly. The have a characteristic appearance on EMG needle examination, along with a random popping sound. Fasciculations are frequently felt and seen as muscle twitches. This, however, is not invariable. Several fasciculations may be visible but not felt, and vice versa. There are several fasciculations that are neither visible nor felt, but may be seen to occur electrically.

Fasciculations, specially in the muscle in the instep of the foot and in the calf, are a normal phenomenon, occuring in the majority of normal individuals sporadically. Fasciculations are a sign of increased excitability of nerve fibers and anterior horn cells in the spinal cord. Repeated fasciculation and cramping may be perceived as a buzzing sensation in the foot.

Fibrillations are very different from fasciculations. They represent spontaneous electrical activity and very feeble contraction of individual muscle fibers. They are NEVER visible clinically, and they are NEVER felt by the individual suffering them. They are detected on EMG examination. They are a manifestation of a muscle fiber losing its nerve supply. Fibrillations do not occur in normal individuals, as a rule.

Fibrillations and fasciculations are not specific for or diagnostic of ALS. Their distribution and other associated abnormalities add up on an EMG examination to suggest the diagnosis.

I append a previous answer, and a link to another similar answer, on fasciculations that you may find relevant.

Good luck!

I've heard a variety of comments on this site that seem to contradict one
another, thus I'll ask them myself!
1. How frequently are fasciculations the first symptom found in an ALS patient? I've
read that they are usually only seen by the doctor once the patient has gone in complaining
of weakness.

2. If the fasiculations are not accompanied by atrophy or weakness, what is the probability
that they are ALS related? Again, I have read that they are only ALS indicative if they are
the RESULT of weakness/atrophy. Thus, I'd think that fasciculations in the absence of the
other symptoms would be a pretty darn good sign.

3. How many people suffer from benign fasciculations, and how often do they last on avarage?
There are a lot of great people who have posted on this site, but I'm not sure that they are
representative of the total "twitching" population. Also, and I suppose this could be deduced
from the answer above, but what percent of folks with fasciculations end up with ALS, versus
something benign?

4. Other than ALS and "nothing", what else could explain fasciculations?

5. How do you define weakness? How do I think about this vis-a-vis soreness, stiffness, aching,
or the feeling of fatigue in muscles?

6. If someone is experiencing twitching, along with muscle soreness and fatigue, but can still go out
and run 3+ miles, is that pretty indicative of a non-ALS situation?

7. What percent of ALS patients experience symptoms in one limb first, versus multiple limbs? My
understanding is that directionally it tends to occur more often in one limb first.

8. If the twitches are primarily in the calves and eyelids, with some roving twitches elsewhere, is
this a positive sign? It seems stress related and/or benign twitches occur most often in calves and
eyes.

Sorry for the litany of questions, but I thought it might serve as a "primer" for others as well. I'd
really appreciate a medical response of general findings, versus case by case examples. While I
recognize that many patients are different, I'm seeking the common aspects that can help those of us
who have recently experienced the twitches let ALS "go" from our thinking.

By the way, based on all that I have read over the recent weeks, I have made a donation to the local
ALS organization. We've got to knock this thing out!

Regards.

Dear Mick:

Thanks for your precisely worded set of questions.

1. How frequently are fasciculations the first symptom found in an ALS patient?

Widespread profuse fasciculations are the hallmark of ALS. Most ALS experts will agree that the diagnosis of ALS is in doubt if no fasciculation is found, clinically and on EMG.
Fasciculations are an early symptom of ALS, and may indeed precede any complaints of weakness by the patient. ALMOST ALL patients with fasciculations who have ALS, however, will have an abnormal neurological examination (i.e. show signs of weakness, atrophy, corticospinal involvement, or bulbar/pseudobulbar involvement) when examined by an experienced neurologist.

2. If the fasiculations are not accompanied by atrophy or weakness, what is the probability
that they are ALS related? Again, I have read that they are only ALS indicative if they are
the RESULT of weakness/atrophy. Thus, I'd think that fasciculations in the absence of the
other symptoms would be a pretty darn good sign.

A normal neurological exam (except for fasciculations) by an experienced and good neurologist makes ALS a very unlikely diagnosis. "Symptoms" are what the patient reports, and "signs" are what the physician observes. Your last sentence is correct if it reads "in the absence of the
other signs".

3. How many people suffer from benign fasciculations, and how often do they last on average?

Sporadic fasciculation is incredibly common, occurs in the majority of normal individuals off and on. Some individuals are more perceptive to these twitches and tend to report them, sometimes from fear of having a serious neurological problem. Most experts agree that a subset of individuals have more prominent, widespread, and persistent fasciculation than should be seen normally. These people often diagnosed to have the benign fasciculations syndrome. This syndrome is obviously quite common, but a prevalence figure is not available. One hundred and thirty seven individuals with benign fasciculations were identified and studied at the Mayo Clinic over a period of 28 years. Of these, 121 were available for a follow-up interview after a mean of about seven years; none had developed ALS, and about half had had a significant improvement. Interestingly, about 16% of the cases have a viral infection preceding onset of symptoms, and about 20% have emotional stresses.

4. Other than ALS and "nothing", what else could explain fasciculations?

A long list of causes - root disease, nerve entrapments (such as carpal tunnel syndrome), specific forms of neuropathy (specially demyelinating), radiation injury to nerves, other forms of motor neuron disease (SMA, Kennedy's disease), the cramp-fasciculation syndrome, syringomyelia, thyroid disease, caffeine, some other drugs, etc.
I guess you are regarding the benign fasciculations under "nothing".

5. How do you define weakness? How do I think about this vis-a-vis soreness, stiffness, aching,
or the feeling of fatigue in muscles?

Weakness is loss of strength. Specifically, on history, an inability to execute specific actions (such as lifting heavy things, opening jars, turning keys, climbing steps, rising from a chair, getting feet into the car, walking on heels/toes, getting out of bed, etc.) due to a lack of strength. Numerous individual muscles are tested for strength during a neurological exam.

6. If someone is experiencing twitching, along with muscle soreness and fatigue, but can still go out
and run 3+ miles, is that pretty indicative of a non-ALS situation?

Not necessarily. Needs a good neurological exam. One hand may be a little weak, for instance.

7. What percent of ALS patients experience symptoms in one limb first, versus multiple limbs? My
understanding is that directionally it tends to occur more often in one limb first.

ALS usually starts in one limb (or else, in the bulbar- face/swallowing/tongue muscles), and then spreads to other areas.

8. If the twitches are primarily in the calves and eyelids, with some roving twitches elsewhere, is
this a positive sign? It seems stress related and/or benign twitches occur most often in calves and
eyes.

Yes, in most cases this pattern suggests a benign problem.

I hope this is useful to you and to others.

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