Symptoms of ALS (Amyotrophic Lateral Sclerosis)
ALS is characterized by progressive muscle weakness due to degeneration of upper and lower motor neurons, with symptoms varying based on onset type (bulbar or spinal) and typically leading to respiratory failure within 3-5 years of diagnosis.
Primary Symptoms
Motor Symptoms
- Muscle weakness and wasting (atrophy) - typically begins focally and spreads to different body regions 1, 2
- Fasciculations (muscle twitching) 3
- Hyperreflexia (increased reflexes) due to upper motor neuron degeneration 1
- Spasticity and muscle stiffness 1, 3
- Muscle cramps 4
Bulbar Symptoms
- Dysarthria (speech difficulties) - progresses to complete loss of speech within approximately 18 months of first bulbar symptom 5
- Dysphagia (swallowing difficulties) - occurs in 47.8%-72.7% of patients, particularly those with bulbar-onset 1
- Sialorrhea (excessive drooling) - due to difficulty swallowing saliva 4
- Poor lip seal and tongue weakness - affecting ability to form food bolus 1
Respiratory Symptoms
- Progressive respiratory insufficiency - present in almost all cases at some stage 6
- Shortness of breath - initially with exertion, later at rest 6
- Difficulty clearing secretions - due to weak cough 6
- Sleep disturbances - including sleep-disordered breathing 6
Symptom Progression
Bulbar-Onset ALS (30-35% of cases)
- Initial symptoms affect speech and swallowing
- Speech deteriorates more rapidly than in spinal-onset cases 5
- Swallowing disorders progress through 5 stages:
- Normal eating habits
- Early eating problems (difficulty chewing)
- Dietary consistency changes needed
- Need for tube feeding
- Nothing by mouth 1
Spinal-Onset ALS (65-70% of cases)
- Initial symptoms affect limbs (problems with dexterity or gait)
- Speech and swallowing problems develop later but eventually affect nearly all patients 1, 3
Extra-Motor Manifestations
- Cognitive and behavioral changes - present in up to 50% of cases 2
- Frontotemporal dementia - occurs in 10-15% of patients 2
- Emotional lability (pathological crying or laughing) 4
Nutritional Impact
- Weight loss - detrimental for survival 1
- Increased meal time and fatigue during/after meals 1
- Malnutrition risk - requires regular monitoring (every 3 months) 1
Important Preserved Functions
- Sphincter control (bowel and bladder function)
- Sensory function
- Intellectual abilities (in most cases)
- Skin integrity 3
Diagnostic Findings
- MRI may show abnormal T2/FLAIR signal in corticospinal tracts and "snake eyes" appearance in anterior horns of spinal cord 1
- Electromyography and nerve conduction studies are key diagnostic tests 1
Treatment Options
FDA-Approved Medications
- Riluzole - oral suspension available for patients with dysphagia 7
- Edaravone - intravenous administration 8
Symptom Management
Dysphagia management:
Respiratory support:
- Non-invasive ventilation
- Invasive ventilation via tracheostomy in selected cases
- Cough assistance techniques 6
Speech difficulties:
- Augmentative and alternative communication (AAC) methods should be introduced before speech deteriorates significantly 5
Other symptom management:
- Medications for cramps, spasticity, and emotional lability
- Treatment for excessive saliva (anticholinergics, botulinum toxin, radiation) 4
Critical Monitoring Points
- Weight and nutritional status - every 3 months 1
- Respiratory function - regular assessment 6
- Dysphagia screening - recommended for all ALS patients 1
- Speech function - to time appropriate AAC intervention 5
Common Pitfalls to Avoid
- Delayed dysphagia assessment - can lead to aspiration pneumonia and malnutrition 1
- Late introduction of AAC - speech typically remains adequate for only 18 months after first bulbar symptom 5
- Inadequate nutritional monitoring - weight loss significantly impacts survival 1
- Delayed respiratory support - early non-invasive ventilation can enhance quality of life and survival 6