Amyotrophic lateral sclerosis (ALS) is better known in the United States and Canda as Lou Gehrig disease. It comes under the umbrella of a group of progressive neurological disorders collectively known as Motor Neuron Diseases (MNDs. ALS is a devastating neurological condition and is uniformally fatal in its outcome.

As the name suggests ALS involves the motor neurons selectively. What are motor neurons you may ask? Motor neurons are neurons (nerve cells) that control voluntary muscle activity. The motor neurons that control voluntary activity like swallowing, coughing, breathing and speaking lie in the brain stem while those that control voluntary activity like walking and moving your hands lie in the spinal cord.

ALS affects motor neurons of both the brain stem as well as the spinal cord. The disease by defination affects only the motor neurons and spares all sensory neurons. Thus patients with ALS have progressive motor weakness but no sensory findings ( no numbness or sensory loss). The disease also spares other brain functions like memory, cognition, orientation, alertness, ability to calculate, eye movements and bladder/bowel function.

That is why ALS is so devastating: it leaves one quadriplegic (completely paralyzed) having difficulty with swallowing, difficulty speaking and breathing but intact of all higher mental functions. Imagine been in a situation where your mind is completely healthy trapped in a completely paralyzed body.

ALS usually affects people in their late 40’s and above. The disease has been known to occur in the younger age groups but in these rare cases it usually runs in the family an entitiy called familial ALS (FALS). The onset of the disease is very insidious and patients may present to their doctor with complaints of a wrist drop or foot drop ( inability to lift the wrist or the foot). Usually the bulbar symptoms of difficulty in swallowing and speaking come later on in the disease course. There is a constellation of signs and symptoms which physicians look for clinically when trying to secure a diagnosis of ALS. 

Though this is technical let me try to explain it to you. If we as physicians find weakness in an arm or leg and the muscles are visibly atrophic (shrunken) but the reflexes (these are the reflexes which we elict by tapping your tendons with our hammers) are brisk, we think about possible ALS. If we find these signs in 3 different limbs it makes the diagnosis more secure. We also look for fasiculations. Fasiculations are visible involuntary muscle twitches under the skin arising from spontaneous discharge of motor neurons. In ALS one may see widespread fasciculations involving different muscle groups as well as fasciculations in the tongue (remember the tongue is also a muscle).

A word of caution here. A lot of us have visible fasciculations, we all have experienced the feeling when one of our muscle such as the eye-lid or thigh suddenly starts twitching. These are called benign fasciculations and do not protend ALS. Only when fasciculations are accompanied by visible muscle wasting and weakness that one should be worried. Benign fasciculations usually occur when one is tired or after heavy exercise and dehydration.

Other symptoms which commonly occur in patients with ALS include cramping especially of bigger muscle groups like that of the back.


If a diagnosis of ALS is been considered, it is imperative that other diseases which can mimic ALS in their presentation be ruled out. Some of these are readily treatable as against ALS for which currently we have no effective treatments. So how is the diagnosis of ALS secured?

When ALS is advanced, the diagnosis is readily apparent on a routine clinical neurological examination. The patient has visible atrophy (wasting) of the muscles of the limbs. Wide-spread fasiculations (muscle twitches) are visible to the naked eye. We as neurologists search for these in the tongue and the big muscle groups on the back. To secure the diagnosis in the earlier stages of the disease when the clinical features are not so florid, your doctor may order a few tests. The most important among these is the EMG (electromyogram). The EMG is a test which is not as bad as it looks. It basically involves putting a recording needle electrode in different muscles of the limbs, back and even the tongue to look for signs of denervation (damage to the motor nerves). There are criteria on EMG that help secure the diagnosis of ALS.


Management Issues in an ALS patient: ALS as a disease is incurable as of now. That said there is a lot which can be done to help a patient with ALS. Only one medication by the name of riluzole is approved for the treatment of ALS. That too prolongs the life expectancy by only a few months. Patients with ALS need a multitude of services and their care is best handled by a multi-speciality team consisting of neurologists, respiratory therapists, gastroenterologist, physical and occupational therapists and speech therapists. As the disease progresses and takes its toll, patients are prone to pneumonia and other respiratory tract infections. As their swallowing and speech functions become progressively impaired, nutrition (feeding) may have to be accomplished via either a feeding tube or a tube in the stomach (we call this a PEG tube).  Physical and occupational therapy helps to preserve motor functions. These patients are greatly helped by assist devices like motorized wheel chairs, a simple straw to aid them in drinking water and other liquids etc.

Tremendous research is going on to find a cure for ALS. Your doctor might also prescribe some vitamins and supplements like coenzyme Q 10. Whether these help is doubtful but they most likely do not cause any harm. You should discuss and other experimental therapies with your physician.

Some diseases which may resemble ALS superficially in their presentation:

1) Benign Cramping Fasiculation Syndrome: I explained this above. A lot of people have visible fasiculations (their muscles quiver) and they may also have complaints of cramps. There is no associated muscle weakness or atrophy. Reassurance is all that is needed.

2) Multi-focal motor neuropathy with conduction blocks: an uncommon neurological condition characterized by involvement of multiple motor nerves (thus resulting in weakness). Conduction blocks are present in nerve conduction study. It resembles ALS in that it presents with weakness and does not cause sensory symptoms.

3) High cervico-medullary junction involvement–if there is a high cervical disk herniation, it at times can present just like ALS.

4) X-linked spinal and bulbar muscle atrophy also referred to as Kennedy’s disease: neuromuscular disease due to mutations in the androgen receptor. Presents with cramps and progressive weakness due to degeneration of motor neurons in the brainstem and spinal cord.


It is imperative that the above conditions be looked for and ruled out before a diagnosis of ALS is arrived at, as some (multi-motor motor neuropathy with conduction blocks) do respond to therapies like intravenous immunoglobulin.


12 thoughts on “ALS

  1. Hi,
    I just read this wonderful article, and I am going to the neuro after my symptoms started to become more pronounced. I started with a terrible pain in my back. Then, the prickiling pain in my left side become a tingling and burning sensation. Then, my migraines started. Next, muscle twitches or fasciculations in my legs, back, neck, under my tongue. My fasciculations become more pronounced at night, while I am sleeping. The problem is that I do not have the muscles weakness or atrophy. I just feel very tired, but I walk and do my exercises very well. I really do not know what I have. Any thougths would be appreciate. Thanks for this wonderful information.


  2. Dear Cleide,
    thank you for writing in and I am glad you found the information useful. ALS or motor neuron disease can most of the times be diagnosed clinically or at least suspected clinically based on the appearance of certain signs and symptoms.
    When I see a patient who has atrophy (wasting) and weakness (of muscles) and in the same limb I see fasiculations with brisk (increased) tendon reflexes my suspicion for ALS is increased. (We elict tendon reflexes by tapping the patient’s tendons with a reflex hammer).
    There are many diseases which may mimic ALS in their presentation but thankfully turn out not to be ALS. My advise to you would be to see your doctor and let him decide what the future diagnostic and therapeutic plan should be.
    Personal Regards,
    Nitin Sethi, MD

  3. That was an excellent article but I am crying because I do my symptoms are just too pronounced to deny. In the last year I have had some strange symptoms but dismissed them because I thought I was just clumsy. Well, after a fall and a hurt toe by doctor found that I had very brisk reflexes, he called it clonus and decided something was going on with upper motor neurons. So he ordered some x-rays first (he’s an orthopedic doc) and then the blood work, MRIs and finally a bone scan. Now he has me set up at a teaching hospital for an EMG with someone who is supposedly famous for EMG/NCV work.

    In the meantime a friend who is a neuro surgeon said we don’t need to wait that long and sent me to a neurologist locally. Monday I will know the results of the EMG/NCV.

    I was told that my protein level in my blood is low but I was actually hoping this is a good sign, although I know that wasn’t my creatine level because the neuro just called in more bloodwork that the ortho didn’t do.

    I have the following symptoms:

    fasics all over, more predominant in my legs
    muscle cramps toward the end of the day-taking baclofen for that
    both legs are okay at the beginning of the day but start hurting and giving out depending on how hard I push myself. I personally do not see any visible atrophy but the weakness is undeniable and everyone tells me I am walking funny. I’m just trying to stay upright.

    In the last two weeks I have had two days where I start out the morning with a horrible migraine (nausea, cannot tolerate light, severe pain). It has taken all day to recover from these.

    SMA runs in my family so I am sure they will rule that out, too, although we haven’t talked a lot about any of it. I haven’t even mentioned ALS but I can tell you my doctor looked concerned.

    One last strange thing: my bones pop constantly, neck (which also aches), shoulders, knees and feet are the worst. It’s annoying like the fascics and just wondered if you knew what this is about.

    I have children. I am only 42 and I am petrified.

  4. Dear Jennifer,
    thank you for writing in. I can only begin to understand the fear and uncertainity that you must be passing through. It indeed is a very difficult time for you. My only advise to you is that there are many diseases which can mimic ALS in its presentation. It is too premature to jump to any conclusions.
    Your doctor shall do a detailed EMG study (when one is looking for ALS, there are criteria according to which EMG has to be carried out. Three and at times four limbs are tested).
    Get the EMG done and then proceed from there. Keep in touch, and feel free to write again. Your doctor though shall be the best person to guide you through this.
    I wish you my very best.

    Personal Regards,
    Nitin Sethi, MD

  5. Thank you for writing in. I am glad you found the information useful.

    Personal Regards,
    Nitin Sethi, MD

  6. An excellent article. I was dxed with als in 08/09, I had a back injury in april/09, pulled muscle slipped disk,[ found 2 mos. later] but Dr. says they arn’t the cause for the debilitated state I’m in say’s he cant find anything significant. I have all the classic symptoms,except I went from walking to a chair in less than 3 weeks after physical therapy, compounded by a TIA,mild stroke which i recovered pretty good. I am losing weight, my legs are totaly useless my breathing is getting worse[still a smoker] but diaphram weak, right arm can only pick up about 1/12 pounds, left arm is still pretty strong.have had all the tests,[blood, spinal fluid,cat scans and mri’s, emg’s ect,] but there is still no proof I have the disease, slight irritation in spinal fluid, the muscle and nerve biopsy shows normal, So where do I go from here? Drs keep sending me to new experts,but I am getting so weak, by the time I find the answer it might be too late, I stopped pt. every time i try to strengthen or work muscles i end up getting weaker, already lost use of leggs. it all started with lower and upper back pain from lifting a heavy object. Any suggestions would be greatly appreciated

    1. Dear Bob,
      thank you for writing in to me. You say you were diagnosed with ALS but later you go on to mention that inspite of a major work-up your diagnosis is still elusive. You say all tests came back negative but your symptoms are progressively getting worse.
      ALS can be a tough disease to diagnose early in its course (usually at this time the patient’s symptoms are mild). Many diseases can mimic ALS in their clinical presentation. That said and done by the time the patient’s symptoms are advanced (meaning the patient is clinically weak and there is muscle atrophy), the diagnosis should be readily apparent both clinically as well on tests like EMG.
      So my advise to you would be to follow up with your doctors. I can sense you are frustrated with the whole process. But it is very important to rule out or rule in ALS. ALS is a fatal neurodegenerative disease (once you get it there is nothing that can be done to cure it). On the other hand if you do not have ALS, there might be treatments that can help you and make you stronger.
      I send you my best wishes.

      Personal Regards,
      Nitin Sethi, MD

      1. Thank you for your reply and your insight. It is much appreciated.

        Yes, you are correct, I am getting frustrated.
        I am anxious to get a correct diganosis-good, bad or ugly-so I can put my mind at ease and receive any treatment that would be helpful.
        It is the diagnosis with ALS with several inconsistencies (per Doctors), that has me frustated and why I seem to be receiving conflicting reports.

        I am scheduled to see a Doctor at the local ALS Clinic in 2 weeks, so hopefully, my third opinion will be the final and correct opinion.

        Thanks for your time and your opinion.

  7. My husband is in the “diagnosing” stage of ALS. He started working out in January of this year, lost about 20 lbs (he is 49, 6ft 4in) now weighs 205. He had just finished a work out about 2 months or so ago and sat down on the couch and our daughter looked at him and said,”what’s up with your arm?” it was twitching like crazy. It has not stopped since. He went for some electrical stem treatments at PT (his sister is a PT) did not help, it would calm it down but in never went away. About 3 weeks ago he noticed some weakness in his hand. Was seen by Ortho MD, referred to Neurology but in the meantime an MRI was ordered, showed some cervical arthritis, some bulging discs, some spondylosis. Went to the Neurologist who after his exam told us that he was quite concerned about ALS. Did an EMG/NCV right then and there and ordered lots of labs. Showed us that my husbands left hand is smaller than his right hand. He called us the next day to say that he did not have “three limbs showing abnormally on the EMG/NCV for a definitive diagnosis of ALS, but that he was still very concerned.” He referred us to an ALS clinic. we are waiting for a call for an appointment with them. Is it possible for these symptoms to come out of nowhere?

    1. Dear Kristen,
      the diagnosis of ALS is not one which is made lightly. A good clinical examination is very helpful supplemented by NCV/EMG study of all four limbs. Sometimes the doctor doing the EMG study may also insert the needle into the tongue and paraspinal muscles to assess for denervation. I would certainly advice that you seek a second opinion. Good luck and feel free to write in again.

      Personal Regards,

      Nitin K Sethi, MD

  8. Dear Sir, i live in the UK and i was diagnosed with a myositis some twenty years ago i am currently going through a neurological review my worst symptoms are very painful severe cramp and spasms with deep fasciculation’s that are mostly invisible these symptoms are particularly bad in my paraspinal muscle but i feel them in many other muscles throughout my body as well. I recently started treatment with baclofen this has help to reduce the severity of the spasms it has also help with the mild Dysphagia i have. I also have pathological weakness in my left leg and finger flex and i am unable to walk on the balls or heels of my feet. I normally have an absent knee jerk but a neurologist recently activated a positive jerk after hammering my knee hard about a dozen times and eventually initiated a reflex that was a very high kick this totally surprised me as i can normally hardly lift my leg of the ground. I have just had an MRI of my lower limb muscles that was normal but my recent EMG test show my upper Trapezius was Polyphasic Neurogenic with Fasciculation’s this was revealed to me in the test room as the examiner was teaching a student and they were discussing the finding as they performed each test i am now awaiting a muscle biopsy. After many year of struggling with what i thought was myositis i have become very aware and consider myself to be quite well informed about neuromuscular conditions. My Neurologist does not comment and avoids question about my reviews until he has all the test results to hand but i am realistic enough to realise that ALS could be a possible outcome, do you agree, many thanks and kind regards, Susan.

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