Episode 152: ALS Fundamentals
Future Dr. Rodriguez explains the symptoms of ALS, including UMN and LMN symptoms. Dr. Arreaza discusses the principles of symptomatic treatment by primary care. This is a brief introduction to ALS.
Written by Adraina Rodriguez, MSIV, Ross University School of Medicine.
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Arreaza: It is rare but you may encounter it and you should be able to identify the most common symptoms. ALS Challenge in 2014: Ice bucket challenge.
Adriana: Patrick Quinn was an ALS patient and activist who created the ICE Bicket Challenge and helped raise US$220 million for medical research.
Arreaza: What is ALS?
Adriana: ALS stands for Amyotrophic Lateral Sclerosis, formerly known as Lou Gehrig’s Disease. It is the most common form of acquired motor neuron disease. ALS is a progressive, incurable neurodegenerative motor neuron disorder with Upper motor neuron (UMN) and/or Lower motor neuron symptoms that cause muscle weakness, disability, and eventually death. There is no single diagnostic test that can confirm or entirely exclude the diagnosis of motor neuron disease.
Arreaza: When should you suspect ALS in a patient?
Adriana: The classic patient presentation is insidious, slowly progressive, and unremitting UMN and/or LMN symptoms present in one of four body segments - cranial/bulbar, cervical, thoracic, and lumbosacral - followed by spread to other segments over a period of months to years.
Arreaza: What would you see on the physical exam when the Patient is in the clinic? There is a system to send signals from your brain to your muscles. It involves basically two neurons: Upper and lower motor neurons. The UMN goes from your cerebral cortex to your spinal cord and there it connects to a lower motor neuron through synapsis. The LMN then sends the signal to your muscles, causing contraction or relaxation. Tell us about the UMN and LMN symptoms.
Adriana:
- LMN Symptoms: Weakness, Fasciculations, Muscular atrophy, Decreased muscle tone (flaccidity) and reduced or absent reflexes.
- UMN Symptoms: Increased tone and increased extremity deep-tendon reflexes, presence of any reflexes in muscles that are profoundly weak and wasted, pathological reflexes (crossed adductors, jaw jerk, Hoffman sign, Babinski sign 50%), syndrome of pseudobulbar affect (inappropriate laughing, crying, forced yawning).
Arreaza: What are important factors to help narrow your differential to ALS?
Multifocal motor neuropathy, cervical radiculomyelopathy, benign fasciculations, inflammatory myopathies, post-polio syndrome, monomelic amyotrophy, hereditary spastic paraplegia, spinobulbar muscular atrophy, myasthenia gravis, hyperthyroidism, and many others.
There are pertinent negatives to look out for:
- Usually negative neuropathic or radiculopathic pain, sensory loss, sphincter dysfunction, ptosis, or extraocular muscle dysfunction (20-30% positive sensory symptoms or “pins and needles” and “electricity” in the affected limbs).
- Note: Cognitive dysfunction does not exclude ALS
Arreaza: What are the diagnostic criteria for ALS
Adriana: Gold Coast Criteria 2019 proposed over El Escorial criteria:
- Progressive upper and lower motor neuron symptoms and signs in one limb or body segment, OR
- Progressive lower motor neuron symptoms and signs in at least two body segments, AND
- Absence of electrophysiologic, neuroimaging, and pathologic evidence of other disease processes that might explain the signs of lower and/or upper motor neuron degeneration.
Arreaza: What diagnostic tests should be ordered for further evaluation?
Adriana:
- Electrodiagnostic studies: Electromyogram and nerve conduction studies (EMG and NCS)
- Laboratory testing: creatine phosphokinase up to 1000u/L
- Neuroimaging: to exclude other causes mainly. Brain MRI whenever bulbar disease is present. Cervical and lumbosacral spine MRI for LMN findings in the arms and legs.
- Genetic testing: FALS 10% of ALS defect in C9ORF72 gene that makes motor neuron and brain nerve cell protein, the exact cause is unknown.
Arreaza: Finally, how do you treat ALS?
Adriana: Disease-modifying treatment: Riluzole is recommended for all patients with ALS. Shown to prolong survival and slow functional deterioration. The mechanisms of action that reduce glutamate-induced excitotoxicity: 1) inhibit glutamic acid release, 2) non-competitive block of N-methyl-D-aspartate (NMDA) receptor-mediated responses, 3) direct action on the voltage-dependent sodium channel.
Arreaza: Riluzole is given 50 mg by mouth twice a day. It may cause drowsiness or somnolence, hepatic injury: Not recommended for patients with elevation of transaminases >5 times the upper limit of normal. It is recommended to monitor for hepatic injury and discontinue if there is evidence of liver dysfunction, such as hyperbilirubinemia.
Adriana: Symptom-based management is the mainstay of treatment. You may involve a multidisciplinary team to treat the symptoms. For example: palliative, hospice, respiratory function management (Noninvasive Positive Pressure Ventilation vs mechanical ventilation.
Arreaza: PCPs may be in charge of managing symptoms because you are the closest provider to the patient. Wherever available, it is recommended to refer your ALS patients to a specialized center. Many patients do not have availability to an ALS center or a neurologist, but they have you to manage their symptoms or complications.
Adriana: Dysphagia: It is a common and distressing symptom. It is suggested PEG tube placement for patients with ALS with normal or moderate respiratory function who have dysphagia. It is controversial, some studies found no benefit on survival or quality of life and other studies suggest that it is safe to give a high-carb, hypercaloric diet to ALS patients.
Arreaza: Spasticity: Use medications such as baclofen and tizanidine may be helpful, and botulinum injections are an option for those who are not responding to oral muscle relaxants.
Adriana: Sialorrhea: Use medications such as atropine, hyoscyamine, amitriptyline, and scopolamine. If these medications are not effective or tolerated, used botox injections into the salivary glands. It is considered safe and useful for treating sialorrhea in patients with ALS. Botox is not only for wrinkles!
Arreaza: There are many other symptoms that will require management, but you are invited to review your preferred source of information such as Up to Date, AAFP, or the ALS Association website.
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Conclusion: Now we conclude episode number 152, “ALS Fundamentals.” You heard from future Dr. Rodriguez that ALS can present with upper motor neuron symptoms, such as spastic muscles and hyperreflexia; or lower motor neuron symptoms, such as flaccid and weak muscles. Some other symptoms include dysphagia, shortness of breath, difficulty talking, fatigue, thick mucus, and pseudobulbar affect. Dr. Arreaza explained that primary care physicians are in a special situation to help diagnose and treat the symptoms of ALS, especially in communities with limited access to an ALS center. You may need to involve a multidisciplinary team to improve the quality of life and possibly the survival of ALS patients.
This week we thank Hector Arreaza and Adriana Rodiguez. Audio editing by Adrianne Silva.
Even without trying, every night you go to bed a little wiser. Thanks for listening to Rio Bravo qWeek Podcast. We want to hear from you, send us an email at RioBravoqWeek@clinicasierravista.org, or visit our website riobravofmrp.org/qweek. See you next week!
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References:
- Galvez-Jimenez, Nestor and Colin Quinn, Symptom-based management of amyotrophic lateral sclerosis, Up To Date, updated on July 31, 2023. https://www.uptodate.com/contents/symptom-based-management-of-amyotrophic-lateral-sclerosis.
- Royalty-free music used for this episode: Good Vibes: Sky's The limit, downloaded on July 20, 2023 from https://www.videvo.net/
