What are the symptoms and management of Amyotrophic Lateral Sclerosis (ALS)?

Symptoms and Management of Amyotrophic Lateral Sclerosis (ALS)

ALS is characterized by progressive degeneration of upper and lower motor neurons in the brain and spinal cord, typically presenting as either bulbar onset or spinal/limb onset, with a mean survival of 3-5 years after symptom onset. 1, 2

Clinical Presentation

• ALS presents in two main forms: bulbar onset (affecting speech and swallowing first) or spinal/limb onset (affecting limb muscles first), with bulbar onset having a shorter life expectancy 3
• Limb onset (approximately two-thirds of cases) presents with focal muscle weakness and wasting in upper or lower limbs, which may start either distally or proximally 2
• Bulbar onset typically presents with dysarthria (speech difficulties) and dysphagia (swallowing difficulties), with limb symptoms often developing simultaneously or within 1-2 years 2
• Progressive spasticity develops in weakened atrophic limbs, affecting manual dexterity and gait 2
• Almost 80% of ALS patients with bulbar onset develop dysarthria and dysphagia 1
• Speech deterioration is rapid, with speech becoming inadequate on average 18 months after the first bulbar symptom 4
• Upper motor neuron signs include hyperreflexia and spasticity 1
• Lower motor neuron signs include muscle weakness, atrophy, and fasciculations 2
• Respiratory muscle weakness eventually develops, leading to respiratory failure, which is the primary cause of death 5, 2

Diagnostic Approach

• No specific diagnostic test exists for ALS; diagnosis is based on clinical history, examination, electromyography, and exclusion of ALS-mimics 2
• MRI of the head without IV contrast is appropriate for initial imaging to exclude other conditions 3
• Common MRI findings include abnormal T2/FLAIR signal in the corticospinal tracts 3, 1
• Videofluoroscopy (VFS) is strongly recommended for clinical evaluation of dysphagia at diagnosis, as it can detect early signs even in asymptomatic patients 6, 3
• Fiberoptic endoscopic evaluation of swallowing (FEES) can identify impaired chewing, tongue muscle deficit, and pharyngeal residues 6

Management

Pharmacological Treatment

• Riluzole is the only FDA-approved drug shown to extend survival in ALS patients 7, 2
• Recommended dosage is 50 mg twice daily, taken at least 1 hour before or 2 hours after meals 7
• Serum aminotransferases should be measured before and during treatment to monitor for hepatic injury 7
• Symptomatic treatments include medications for cramps, pathological crying or laughter, spasms, and spasticity 8
• Anticholinergics can be used to manage excess mucus in the respiratory tract 8

Nutritional Management

• Regular nutritional status assessment (BMI, weight loss) should be performed every 3 months to detect early malnutrition 3
• For patients with dysphagia, food texture should be adapted to facilitate swallowing 3
• Implementation of postural maneuvers and use of thicker liquids and semisolid foods with high water content instead of thin liquids is recommended 3
• Weight loss due to dysphagia can be addressed by eating frequent small meals 8
• Enteral nutrition via feeding tubes (preferably gastrostomy) is recommended when oral intake becomes insufficient 3
• Percutaneous endoscopic gastrostomy (PEG) should be considered before respiratory function significantly deteriorates 3, 8

Communication Support

• When speech can no longer be understood, adaptive strategies such as sign language, mime, posture, and communication apparatus ranging from note pads to advanced computer systems should be implemented 8
• Augmentative and alternative communication (AAC) methods should be initiated when speech deteriorates to poor intelligibility 4

Respiratory Support

• Non-invasive ventilation prolongs survival and improves quality of life 2
• External respiratory supportive therapy using a nasal mask or invasive respiratory support via tracheostomy can be used to manage respiratory weakness 8

Palliative Care

• A palliative care approach should be adopted from the time of diagnosis 3
• Early referral to palliative services helps establish relationships with staff and address end-of-life issues 3
• During the terminal phase, management focuses on restlessness, anxiety, pain, and dyspnea 8

Important Considerations

• Multidisciplinary care significantly improves survival compared to neurological care alone 9
• Bulbar-onset ALS patients are more susceptible to delayed evaluation and AAC intervention 4
• Patients should be informed about treatment options for excessive weight loss and respiratory weakness before dysarthria severely hampers communication 8
• Special equipment for mobility should be made available earlier than in other muscle diseases due to the faster progression of ALS 8
• Riluzole-treated patients taking other hepatotoxic drugs may be at increased risk for hepatotoxicity 7