Disease Description (Causes and Symptoms)
- Definition: A group of degenerative nervous system diseases in which the upper and lower motor neurons that control motor function (the motor cortex of the brain, and motor neurons in the brainstem and spinal cord) are progressively damaged, causing muscle weakness, muscle atrophy, dysphagia (difficulty swallowing), and respiratory failure (including amyotrophic lateral sclerosis, ALS).
- Causes and pathophysiology: The exact cause is unknown. Genetic predisposition (familial cases), excitotoxicity (glutamate), oxidative stress, immune mechanisms, susceptibility to infection, and abnormalities in axonal transport involving microtubules are thought to act in combination. The disease progresses through degeneration of upper and lower limb motor neurons, followed by muscle atrophy, fibrosis, and respiratory muscle weakness.
- Main symptoms: Progressive muscle weakness (in the limbs and muscles involved in speaking and swallowing), muscle atrophy and degenerative findings on electromyography, muscle cramps and spasticity, gait disturbance, weight loss, cough and shortness of breath (worsening during sleep), and dysphagia (risk of aspiration).
Treatment Methods
- Definitive treatment: There is currently no cure. Although medications cannot fundamentally stop disease progression, some drugs may slow the rate of progression.
- Riluzole: Used as standard treatment and known to extend survival by several months (usual dosage: 50 mg orally twice daily).
- Edaravone (approved in some countries): Reported to delay the rate of functional deterioration in certain patient groups (check country-specific guidelines for indications and use).
- Symptomatic and supportive treatment (important)
- Respiratory support: Regular assessment of respiratory function (FVC, SNIP, etc.). When respiratory muscles are weak, noninvasive ventilation (NIV; e.g., nighttime positive-pressure ventilation) may improve quality of life and extend survival. As the disease progresses, tracheostomy and mechanical ventilation may be considered (taking the patient’s wishes and quality of life into account).
- Nutrition and swallowing management: When dysphagia develops, provide education on eating safely and preventing aspiration during oral intake; if necessary, consider nutritional support through PEG (percutaneous endoscopic gastrostomy).
- Rehabilitation: Physical and occupational therapy to preserve muscle strength and prevent joint contractures; use of assistive devices such as braces and walkers.
- Symptom medications: Spasticity (baclofen, tizanidine), muscle cramps and cramping pain (mexiletine may be considered depending on the literature), excessive salivation (anticholinergics, botulinum toxin injections), and symptomatic treatment for pain, depression, and insomnia.
- Multidisciplinary approach: Integrated management involving neurology, pulmonology, rehabilitation, nutrition, speech-language therapy, home nursing, and hospice teams is important for improving prognosis and quality of life.
- Preventive and routine measures
- Infection prevention: Influenza and pneumococcal vaccination is recommended (consider individual risk and timing).
- Medication and surgery precautions: Exercise caution with medications that may cause respiratory depression (such as excessive sedatives). Consult with the anesthesiology department in advance before anesthesia or surgery.
- Complications: Respiratory failure, aspiration pneumonia, malnutrition and weight loss, pressure sores, thrombosis, depression, and social isolation.
- Prognosis: There is considerable individual variation. In general, median survival after onset is several years (a range of 2–5 years), and some people survive for more than 5 years (standard statistics have reported that approximately 20% survive 5 years, among other findings). It varies depending on the disease type, site of onset, timing of respiratory muscle involvement, and access to treatment.
Checklist Before an Outpatient Visit (Including Example Questions)
- What to prepare
- A list of all medications and nutritional supplements currently being taken (including doses and administration times).
- Copies of previous test results (EMG/nerve conduction studies, MRI, recent blood tests, pulmonary function tests, etc.), if possible, or a summary.
- A record of recent symptom changes (when they began, patterns of improvement or worsening, changes in swallowing, breathing, sleep, and weight, etc.).
- Whether assistive devices are being used (cane, walker, respiratory support device, etc.) and notes on changes in activities of daily living (ADL).
- Family history (similar diseases and whether there are hereditary diseases) and occupational or environmental exposure history.
- Example symptom checklist to show the doctor during an outpatient visit
- When and in which areas did weakness begin? (e.g., fingers, ankles, speaking)
- Do you have swallowing problems (choking, coughing, weight loss)?
- Do you experience shortness of breath at night, daytime fatigue, or breathlessness during daily activities?
- Do you have walking or balance problems, or have you experienced falls?
- Any recent changes in emotional state (depression, anxiety) or sleep?
Examples of General Questions to Ask the Doctor
- What is the exact diagnosis of this disease (e.g., ALS), and how was it distinguished from other diseases?
- What is the expected rate of disease progression and the long-term prognosis?
- What are the expected effects and side effects of currently available medications (e.g., riluzole and edaravone)?
- What tests should be performed regularly if respiratory function worsens? When should NIV (noninvasive ventilation) be started?
- If swallowing worsens, when do you recommend PEG, and what are the procedure and complications?
- How can rehabilitation, assistive devices, and psychosocial support (family education and caregiver support) be accessed?
Examples of Disease-Specific Questions
- Do you recommend genetic testing (a gene panel)? If a familial predisposition is identified, how are family testing and genetic counseling conducted?
- What is the current status of my respiratory test results (FVC, SNIP, nighttime oxygen saturation, etc.)? What are the specific criteria for when to consider starting noninvasive ventilation (NIV)?