Amyotrophic Lateral Sclerosis – ALS / Motor Neuron Disease
This is a group of diseases of unknown cause that affect the nerves of the brain, brain stem and spinal cord that control voluntary movements and leads to the loss of the ability to transmit nerve signals from the above organs to muscles. There are indications of genetic (gene mutations) and environmental factors such as exposure to toxic substances, trauma, diet, unknown viruses – pathogens, behavioral and occupational factors or even autoimmune mechanisms. Its progress is rapid and reduces life expectancy. It occurs 20% more often in men, and usually its symptoms occur between the ages of 55-75 years. According to epidemiologic statistics of 2019 its prevalence is 4.1-8.4/100,000, where as its global incidence is 0.6-3.8/100,000, and in Europe percentages are the highest 2.1-3.8/100,000. 90-95% of cases are sporadic, ie there is no family history or exposure to risk factors. About 5-10% of the remaining cases are autosomal hereditary, either dominant or recessive. If the pattern is dominant, the symptoms become evident from adolescence or adulthood, whereas in recessive cases, the symptoms occur from childhood or adolescence.
Progression appears to be slowed down in people who experience symptoms at younger ages than 40, slightly obese, with a disorder restricted to one lower limb and those with symptoms of higher motor neurons.
Symptoms
- Muscle contractures in arms, feet, shoulders or tongue.
- Muscle cramps (especially at night).
- Hard and stiff muscles.
- Muscular weakness and atrophy in the hands, feet, throat and diaphragm, leading to problems of fine motor skills, falls.
- Speech problems.
- Difficulties in chewing, swallowing, leading to weight loss, difficulty in movement and breathing, leading to risk of respiratory infections, aspiration and respiratory failure.
Diagnosis
- Clinical examination.
- Genetic tests.
- Electromyography.
- Nerve conduction velocity test.
- Axial and magnetic tomography, X-rays.
- Blood and urine tests.
- Muscle biopsy.
- Myelograph of cervical area.
- Lumbar puncture.
Management
There is no cure, but treatment of individual symptoms with appropriate medication, physiotherapy, occupational therapy, speech therapy, nutritional support (even with suction devices and feeding tubes), respiratory support (oxygen masks, respirators, cough devices), use of speech aids and movement.
Canadian best practice recommendations for ALS
A summary of the American Academy of Neurology (AAN) guideline regarding management and care of the patient with amyotrophic
lateral sclerosis (ALS). Recommendations are presented for drug, nutritional, and respiratory therapies.
For Doctors:
For Patients:
Information about clinical trials conducted globally: https://www.centerwatch.com/clinical-trials/listings/?View=A and
https://clinicaltrials.gov/ct2/home
References
- E. Longinetti, F. Fang, Epidemiology of amyotrophic lateral sclerosis: an update of recent literature, Curr Opin Neurol. 2019 32(5): 771–776, Published online 2019 Aug 12.
- H. Tai et al, Amyotrophic Lateral Sclerosis and Myasthenia Gravis Overlap Syndrome: A Review of Two Cases and the Associated Literature. Front. Neurol, 2017, 8, 218.
- L. Ng, F. Khan, C.A Young, M. Galea , Symptomastic treatments for amyotrophic lateral sclerosis/motor neuron disease, Cochrane Database Syst. Rev., 2017.
- M.L. Camparani et al, Neuromuscular Junction impairement in amyotrophic lateral sclerosis: reassessing the role in acetylcholinesterase, Front Mol. Neurosci., 2016, 9, 160.
- NORD (National Organization for Rare Disorders), Rare diseases, Amyotrophic Lateral Sclerosis, https://rarediseases.org/rare-diseases/amyotrophic-lateral-sclerosis/
- Symptoms and Diagnosis, ALSA.org
- T. Lenglet, J.P. Camdessanche, Amyotrophic lateral sclerosis or not: keys for the diagnosis, J. Neurol., 2017, 173950, pp. 280-287.
- U.S. Department of Health and Human Services, National Institute of Neurological Disorders and Stroke, Amyotrophic Lateral Sclerosis (ALS) Fact Sheet, https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Amyotrophic-Lateral-Sclerosis-ALS-Fact-Sheet
- V. S. Boyce, L. M. Mendell, Neurotrophins and spinal circuit function, Frontiers in Neural Circuits, Frontiers Media S.A., 2014.