What is Cramp Fasciculation Syndrome?
CFS is what is called a peripheral nerve hyperexcitability disorder - this means that the nerves outside of your brain and spine are firing more than average. These disorders exist on a spectrum, from normal through to very severe.
At the most severe end, we have Morvan's syndrome, which can be fatal, and Isaac's Disease, which can be incredibly severe and disabling. At the less severe end we have benign fasciculation syndrome, and the subclinical fasciculation and cramps common to most everyone. In the middle we have CFS and mild neuromyotonia, which has similar symptoms but more severe.
Cramp Fasciculation Syndrome is benign. It is not a progressive disease, and fasciculation without progressive weakness for more than five years is certainly not ALS (A. Lagueny 2008). While it can be very uncomfortable, it is not progressive and will not kill you.
Understanding the Symptoms
A fasciculation is an abnormal stimulation of a single muscle fibre. The muscle nerve is stimulated, the muscle bundle fires, the twitch happens.
A cramp is an abnormal tightening of a muscle that is sustained and painful and is associated with neuro-electrical activity. Cramps can be fairly mild, or so severe as to cause transient limb paralysis and lasting pain.
Most people get cramps and fasciculation! I have never spoken to someone who can't recount an eye or a thumb twitch. I would be absolutely gobsmacked if an adult had never had a cramp. When studied, at least 70% of people show some occasional fasciculation. However, if you have received a cramp fasciculation syndrome diagnosis, your cramps and fasciculation will be much worse than is average.
CFS is a rare diagnosis. There's a 0.4% estimate floating around but that's not diagnosis, that's the number of people who report fasciculation and cramp combined in a study of 780 people who were already pre-screened by telephone. As a diagnosis, we can only assume that the prevalence is much, much less than 4/1000.
What Causes CFS?
Cramp fasciculation syndrome is a syndrome, which means that there is a common set of symptoms, but that there may not be a common cause. Indeed, we know that CFS has a number of causes:
Autoimmune causes: We know that it can be autoimmune in nature.
Post-viral triggers: It can be triggered by a viral infection (post-viral CFS).
Injury and lesions: Some cases of CFS are caused by injury, and rarely by lesions on the brain.
Cancer-related: Sometimes CFS is a symptom of cancer, mostly lung and thymus cancers.
Thyroid issues: It is possible that thyroid issues can cause CFS. It may be worth mentioning this to your doctor.
Toxins and allergens: Severe allergens can cause the syndrome, as well as a number of poisons. Heavy metal poisoning can cause the syndrome, and I found a few references to gold toxicity causing the syndrome!
The underlying cause or causes of the illness are often never detected. We may need to learn to suffer without answers.
A significant minority of cramp fasciculation syndrome sufferers test positive for antibodies which attack the nerves. It is very likely that a large portion of CFS cases are caused by an autoimmune disorder.
Recovery prospects: Injury, post-allergen and post-viral causes are very likely to recover over time. Slowly, 18 months to 5 years. Some toxins can cause permanent damage but likewise we expect that removing the toxin will fix the syndrome. However, many cases of CFS are chronic, and will be a greater or lesser problem for the rest of your life. It can be very challenging to be diagnosed with a disease with no cause and no end.
A Personal Introduction
Now, I am not a doctor. I'm just living with this condition and trying to understand it as best as I can. It's important to have a good relationship with your medical team, as it's down to you and them to test what works for you best.
I am a man in my mid-thirties. I first started experiencing notable symptoms in October 2024. Fasciculations from 20-200 times a minute. The twitches occur in every muscle. My lips, my face, my ribs and abdomen. I have had twitches along my penis, which is very annoying, and in my arsehole. Muscles inside my ear have twitched, an incredibly loud thumping, thankfully not often. My extraocular muscles have twitched, the muscles that move my eyes, which is very, very unpleasant.
Severe cramps that would take my breath from me. I will easily have dozens of minor cramps a day, and 1-3 more serious cramps. I feel a constant DOMS-like discomfort, like I'd overdone it at the gym. A shakiness and a lack of confidence in my muscles which was extremely concerning.
I experience many novel paresthesias, odd sensations, from tingling or pins and needles, to transient movement sensations, to a feeling that I can only describe as being gently slapped with wet lettuce leaves. The tip of my tongue started getting a very strange menthol sensation, like I'd sucked a mint, which has spread slowly and now it is my whole tongue, and down my throat and into my sinuses.
I get some myoclonus, sometimes my limbs do a big twitch. My sleep has been disrupted. I've had some constipation, a very annoying sensation like I can't relax to poo. Sometimes I get pretty bad brain fog, and fatigue. An inventive parade of horrors.
I was diagnosed with cramp fasciculation syndrome in December of 2024. Symptoms have not abated but there has felt to be some kind of settling of symptoms.
Lifestyle Adaptations
I want to emphasise here that CFS is not one single disease. While it is likely to be an autoimmune disorder, there are enough causes that any given case might not be. This makes making firm recommendations for treatment, mitigation and intervention difficult. What works for one person might not work for another. Think of this section as things you can try, and directions to experiment in.
Physical Management
Get a massage gun. For me, massage is agonising, and the only thing that provides non-medicine relief. A massage gun allows me to work out tight muscles, and gives the pressure and angle that I need. It also means that I suffer a bit less. It can be severely uncomfortable to have someone else massage me, and it can be difficult to communicate exactly what's wrong.
Do stretches. I'm serious. I'm doing fifteen minutes or more of stretching every day. Just a few minutes at a time, but at least five minutes of stretching at a time. I do simple yoga poses once a day, don't beat yourself up if you can't maintain a position. Yoga is all about doing what your body can handle. Here is an example of the sort of stretches/yoga that I do. If you're in pain doing a stretch, stop it. If you cramp up during a stretch, stop it.
Body Care and Stress Management
You'll need to be mindful about taking care of your body. This syndrome is correlated with anxiety and stress, you need to reduce stress on your body as much as you can. This means you need to be hydrated and well slept.
Stay hydrated: Absolutely make sure you are well hydrated. I drink sugar-free sports drink on top of regular water. Dehydration is the enemy of productivity.
Sleep hygiene: Try for good sleep hygiene. Easier said than done, but better sleep improving symptoms is pretty consistently reported.
Mindfulness: Consider mindfulness and meditation practice. I make sure to do a couple of breathing exercises as I do yoga - just three deep and gentle breaths in through the nose and out through the mouth.
Temperature and Environment
I find it gets worse as I get colder. The colder it is, the more likely I am to cramp or experience discomfort. I find I take a lot of hot baths. Many people report temperature exacerbating symptoms, but it does not seem to be universal. Some people say heat exacerbates symptoms. I find cold makes it worse.
Diet and Substances
Alcohol: I have found that alcohol significantly increases my symptoms, both in the moment and for a day or so afterwards. I've pretty much cut alcohol from my diet, as even a glass of wine can increase symptoms. Sometimes it's worth it though.
Dietary approaches: Some people have reported success from various diets. It could be worth trying a very low carb diet, an anti-inflammatory diet, a vegan diet or a low-fat diet. I know that's basically every type of diet on the planet, but there's not much hard information beyond anecdotal evidence. You're on your own there, my friend.
Caffeine: It is probably worth removing caffeine from your diet. Stimulants of any kind are somewhat frowned upon by neurologists w/r/t this condition. However, a life without coffee is a life not worth living for me, and I tested removing caffeine to find no reduction in symptoms.
Exercise - The Goldilocks Problem
Do exercise. This is an extremely tough one for me. If I do no exercise, my muscles end up feeling extremely bad. I feel like the twitching is worse if I am sedentary. However, if I do too much exercise, even by a tiny amount, the ensuing cramps are unbearable. If I do the Goldilocks amount of exercise, then I still get cramps and twitching but it is less uncomfortable.
This is made more difficult for me, because I'm getting pretty bad exercise intolerance. It has sometimes only taken a little bit of exercise to have me in severe discomfort. I was asked if I could expand on what I mean by "Goldilocks Zone" here, but the fact is, sometimes I'm essentially 90% of normal, and sometimes a 3km walk will leave me shaking and sweating in pain. It's maddeningly variable.
Tracking and Mental Health
Keep a health diary. There is good evidence that diet can exacerbate symptoms in some cases. If glutamates are causing you grief, it's very useful to have a health diary that includes symptoms, diet and medication, as that will allow you to isolate dietary triggers.
Consider therapy. Ideally with a therapist who has experience with chronic illness, but not necessary. Personally, I was really struggling with the idea of being diagnosed with a benign chronic pain disorder. I was upset that I would have to change my life, my self-identity, to manage this disorder. Going to therapy helped me smooth some of this out. Your mileage may vary but, for me, the symptoms are so varied and so unpleasant that talking to someone about it, explaining my experience, was very useful.
Supplements
I take supplements, and many people claim that supplements help them. I suggest magnesium glycinate, and potassium supplementation. I also take a men's multivitamin. Many people who have been diagnosed with CFS show normal electrolytes in blood tests, so supplementation may not do anything. However, it's a low cost, easy intervention that makes me feel like I'm doing something for my health, and extra magnesium literally can't hurt you. Too much extra potassium is not super good for you so take as directed, don't go eating the whole bottle of potassium capsules.
Medical Interventions
There are a number of medications that can treat Cramp Fasciculation Syndrome. There's a few different types, so I'll explain them in groups.
First-Line Treatments (Strong Evidence)
OLD SCHOOL ANTICONVULSANTS - This is your carbamazepine and oxcarbazepine and so on. They work by blocking the sodium channel in your nerves and this can significantly reduce twitch and cramp. I've never tried them, because the blood monitoring and side effects are concerning to me. However, this is neurologist and patient confirmed. These are effective drugs, but they have limitations.
If your symptoms are severe, definitely test these. The trick is to start low and slow. You're not looking for anti-epilepsy doses, you should see improvement with fairly low doses. On these drugs it's important to have frequent blood monitoring, they can have pretty severe side effects. Carbamazepine has been shown to improve symptoms in at least 70% of patients.
CALCIUM CHANNEL AFFECTING GABA AGONISTS - These are drugs like gabapentin and pregabalin. These drugs affect how your nerves signal, and in some cases of CFS can significantly reduce symptoms. I take pregabalin, and see a reduction in twitching and cramps of about 2/3rds. It doesn't completely remove twitches and cramps, but it does significantly suppress them.
They aren't ideal drugs in a lot of ways. I find pregabalin can make me feel stupid and sleepy, but it's worth testing because the relief is significant for me. Gabapentin has some pretty good evidence that it's helpful, with 77% of patients reporting benefits!
Second-Line Options (Moderate Evidence)
NEWER ANTICONVULSANTS - There has been, relatively recently, some chatter about lamotrigine or levetiracetam being used to treat CFS. However, they tend to be somewhat better tolerated than the old school anticonvulsants. They still require blood monitoring for pretty severe side effects. Note: Lamotrigine has a BLACK BOX WARNING for Stevens-Johnson syndrome - requires very slow dose escalation.
MEMBRANE DRUGS - In cases of CFS where there is a suspected autoimmune cause, the same drugs which treat neuromyotonia can treat CFS. These drugs will not be useful in cases of CFS which are not autoimmune, but mexiletine could be worth testing if you suspect autoimmune. Mexiletine is hard on the heart, and needs cardiac monitoring.
Limited Evidence Options
BENZODIAZEPINES - These have a dual purpose, they act directly on the nerves as an anti-convulsant and are also extremely effective anti-anxiety drugs. Many doctors are wary of prescribing benzodiazepines due to addiction potential. Don't expect benzodiazepines to be your first line, or only line of defence, but they can be very effective in some cases. There's not much CFS specific evidence though.
MUSCLE RELAXANTS - Baclofen is probably the most common. Many people with CFS report that baclofen doesn't really do anything for them. I found that it significantly reduced cramps, but that the side effects weren't really worth it. There are a few other ones which you may want to try like tizanidine and cyclobenzaprine but I have not tried them, and I have not seen study on their efficacy.
SSRI/ANTIDEPRESSANTS - Often neurologists and primary care physicians will suggest antidepressants. While they may be useful to treat anxiety and depression, they will not impact the twitching or cramping. To be very frank and open, I do not take SSRIs because they give me anorgasmia, an inability to orgasm, which completely overrides any benefit I might get from the antidepressant effect.
This syndrome is likely to be chronic. You're liable to be in this for the long haul. It's important that you have a close relationship with your medical professional to ensure best treatment. There's a lot of unknowns with this syndrome, and you may need to test a number of treatments to find what works best for you. The aim here is best quality of life, and best quality of life probably doesn't mean zero symptoms. If drug side effects are too much, then no amount of symptom reduction is worth a reduced quality of life.
What To Do From Here?
Here's a checklist of things to do when you're ready:
CFS, Anxiety and Lou Gehrig's Disease
If you're like me, you would have been very concerned after google searching symptoms. For me, it was an absolute relief to see a dedicated expert who assured me I was not dying. For many with the fasciculation syndromes, anxiety is an integral part of the syndrome. Anxiety about the symptoms exacerbates the symptoms which in turn exacerbate anxiety.
However, Cramp Fasciculation Syndrome is benign, and definitively benign. In studies of more than hundreds of patients, there has been no increase in progressive disease, like parkinsonism, ALS, and so on over the normal population. To be absolutely clear, you could still be diagnosed with a motor neuron disease like ALS, but it would just be really, really bad luck and nothing to do with the cramp fasciculation syndrome.
If anxiety about the disease is a significant part of the experience for you, you will need to find methods of dealing with the anxiety, whether by therapy, medication, whatever you have to do, because it will hinder your ability to cope with a chronic condition.
Indeed, fasciculation syndromes are so common, so commonly associated with anxiety, and as fasciculation is so associated with ALS, often medical practitioners get anxiety about fasciculations. They call it FASIC, fasciculation anxiety syndrome in clinicians. I feel like I am not particularly anxious, and after getting a diagnosis, and having no progressive weakness, I'm not concerned with motor neuron disease.
Medical Barriers and Costs
I have unfortunately not had a completely even medical experience. On my letter of diagnosis, the neurologist listed the cause as "Biochemical Anxiety" and I'll be honest, I don't know if that's a thing. It felt pretty irritating and dismissive to have what is relentless physical symptoms to be reduced to something which isn't a recognised medical term. It was frustrating to have my GP confirm that he'd never heard of "biochemical anxiety" but to be fair, the man hadn't heard of Cramp Fasciculation Syndrome.
While I have a close and good relationship with my GP, I have had trouble communicating to him the discomfort I experience. I have heard from some Americans that CFS is not considered a disabling condition, and it's possible that receiving supports and concessions would be difficult. It's very possible that your primary care practitioner will be unfamiliar with this condition due to the rarity of it, and you will need to drive testing and treatment.
Financial and Work Impact
I have found that costs have increased for me. I find myself reaching more for convenience and ease if I'm feeling bad. I have had to buy a number of things to make my life easier. I'm lucky enough that the State can assist me in some ways. Many people will not have this luxury.
As an effectively invisible disease, it can be challenging to find accommodations. This syndrome can impact physical jobs significantly. I just can't reliably carry heavy things, and unless I'm on a pretty strong dose of pregabalin, even holding a screwdriver can cause relentless cramps in my hands. Standing for long periods can also be challenging.
If your work is being affected, consider getting a doctor's note describing this as a chronic medical condition. Having documentation can help with workplace accommodations. Some people manage fine in their jobs, but others struggle significantly, and it's worth being prepared for both possibilities.
A Couple of Things I Find Comforting
Gold can cause it. No, really. Gold toxicity, from supplements, environmental exposure, or even old medical treatments, has been linked to cramp fasciculation symptoms. That's how weird and fragile the nervous system is. It also means that if your nerves are freaking out, it doesn't necessarily mean something catastrophic is happening.
Some people with CFS get massively jacked legs from the constant movement. Hypertrophy of the legs! How about that?
You are not dying. If you've had a CFS diagnosis and your neurologist isn't panicking, you're probably not dealing with a progressive motor neuron disease. That terrifying possibility often haunts people early on but CFS is not ALS.
You are not imagining it. Twitching, burning, brain fog, cramps that knock the wind out of you, these are all real, recorded, and shared by others. You're not broken or delusional.
Thank you for reading this. I hope this document proves helpful for you. Feel free to reach out to me if you found it helpful or have any suggestions for me to include. The postscript here is some wild speculation about this syndrome that I have collected. Please take anything after this point with a heavy grain of salt.
WILD SPECULATION
TRPA1 Theory: There's evidence of specific TRPA1 mutations in familial cases of peripheral nerve hyperexcitability. I suspect that it's more common than just familial cases. Black rock scorpion venom is a TRPA1 antagonist - what occurs in exposure to TRPA1 antagonists in those with a TRPA1 mutation? Highly speculative, I think it could be a treatment. Wasabi and menthol and chili stimulate TRPA1 receptors. Test chili plasters and tiger balm to see if it increases or decreases symptoms. Suspect TRPA1 involvement because of menthol sensation on tongue.
CASPR antibodies: Worth testing? For most, probably not. CASPR antibodies are cheaper to test for than ever before with good blood serum tests available, but only a minority of CFS sufferers show antibodies on testing. Possibly worth testing if severe, but probably a second opinion to rule out neuromyotonia would be cheaper and faster and do the same thing.
Links with BFS, ME/Chronic Fatigue, post-viral, post-covid or post vaccine: BFS is, forgive the weasel words, probably in many cases related to the autoimmune mechanism that can cause CFS. Some BFS sufferers experience brain fog, increased cramps, and paresthesias as well. However, as fasciculation is so common, "nearly 100%", that it's hard to tease out what is anxiety driven reaction to essentially normal bodily behaviour, and what is pathological.
This is something I'd like to do some surveys on, but frankly r/bfs is a hellhole of hypochondriacs. No offense to the mods, you poor bastards. We have A LOT of anecdotal evidence that covid can trigger BFS and CFS. A LOT A LOT. I think this is extremely plausible. We already see BFS/CFS caused by other viruses and covid is demonstrably neurotoxic.
HOWEVER! we also see A LOT of anecdotal evidence that covid can also cause ME/Chronic Fatigue Syndrome (that is to say myalgic encephalitis/Chronic fatigue syndrome. I guess there's only so many acronyms to go round). As there is overlap in symptoms between BFS/CFS and ME/Chronic Fatigue, I think it could be plausible that there's something of the same autoimmune cascade, but ME/CFS being more CNS rather than the peripheral system. Feels speculative but this is also something that I want to do more research into.
We also have a few accounts of people reporting CFS diagnosis after covid vaccine. I think this is plausible, the vaccine is literally designed to provoke an immune response. There is no reason to think that an overreaction may not occur in such a way that causes or triggers CFS. However, this seems much more rare than CFS triggered by getting covid. I'd love to look into this further, there is a frustrating political confounding as well.
Abnormal neural harmonics theory: It's possible our sensorium is generated by a harmonic wave from the nerves. Abnormal sensorium, paresthesia, misfiring nerves inducing abnormal harmonics? Gonna have to write a whole post about this.
Peripheral v central: While PNH is pretty well established, could be possible that central causes might induce the symptoms? Pinched nerve = localised CFS? Some anecdotal evidence. Lesions on the brain or spine is plausible, limited evidence ultimately. Very theoretically possible.
MDMA/psychedelics therapy: Get fuckin on it lads get wild with it get catatonic on ketamine and try and feel your twitches really feel them. Why not? Where not contraindicated by medications of course, but what if it can help, physically, mentally, or spiritually? I assure you that if you get possessed by an 8th dimensional ayahuasca demon then your twitches will be less of a problem.
Radical treatment options: Low dose naltrexone, IVIG, plasmapheresis, other off label drugs. Low dose naltrexone is some fuckin interesting shit. I'm gonna have to write a whole post on that. ME/CFS can be treated with low dose naltrexone????? IDK about plasmapheresis. If you're fuckin rich yeah go hard replace all your blood. Otherwise... why? For 6-9 months of relief? Take some gabapentin and call me in the morning.