Weakness Equals ALS.
Medically reviewed and written by Ashwin Malhotra, M.D. — April 5th, 2021
As a Neurologist, one of the hardest things I have to do is tell a patient they have Amyotrophic lateral sclerosis (ALS). This is a relentlessly progressive neurodegenerative disorder of the peripheral nervous system. The word “neurodegenerative” means “Neurons or cells are dying and degenerating.” Neuron/Cell death leads lack of function, which after sometime we notice as clinical symptoms. One of which is muscle weakness. So, naturally our minds conclude, new muscle weakness must be ALS. The reason we, even as doctors sometimes, jump to ALS as the number 1 disease on the list of motor neuron diseases (motor neuron is the type cell/neuron that is degenerating here) is because ALS is the most common Motor Neuron Disease. However, what is often left out of the common knowledge is how common is the most common motor neuron disease? The answer is about 2 to 4 in 100,000 persons.
There is a long list of other possibilities, most less dreadful than ALS, that are more common as the underlying etiology of Weakness.
|All Muscle Twitching Equals ALS.
|New Fatigue Equals ALS.
|All Dysphagia Equals ALS.
Muscle Twitching is another symptom which makes patients and doctors nervous and brings ALS into consideration. However, there are again many other disease states which can cause muscle twitching, more commonly in some cases, than ALS. Benign Fasciculation Syndrome is one to consider, which is often mistaken for ALS. Generalized Fatigue and Dysphagia fall into the same category. No one symptom is diagnostic for ALS, however all these can be seen in ALS and many other disorders.
So in summary, it is the responsibility of the Physician to discuss the possibility of ALS when any of the symptoms suggestive of ALS are present. But it is also necessary to share the incidence and prevalence data with patients and to exhaust other possible differential diagnoses before assigning the diagnosis of ALS to a patient. Review of this topic in detail is beyond the scope of this blog post, but more detailed literature can be found elsewhere:
- Al-Chalabi A, Hardiman O. The epidemiology of ALS: a conspiracy of genes, environment and time. Nat Rev Neurol 2013;9(11):617–628. doi:10.1038/nrneurol.2013.203.
- Chiò A, Logroscino G, Traynor BJ, et al. Global epidemiology of amyotrophic lateral sclerosis: a systematic review of the published literature. Neuroepidemiology 2013;41(2):118–130. doi:10.1159/000351153.
- Quinn, C. and Elman, L., 2020. Amyotrophic lateral sclerosis and other motor neuron diseases. CONTINUUM: Lifelong Learning in Neurology, 26(5), pp.1323-1347.