Introduction
Epidemiology
- Incidence: 2.00 cases per 100,000 person-years
- Peak incidence: 60-70 years
- Sex ratio: more common in males 2:1
<1 | 1-5 | 6+ | 16+ | 30+ | 40+ | 50+ | 60+ | 70+ | 80+ |
Clinical features
- fasciculations
- the absence of sensory signs/symptoms*
- the mixture of lower motor neuron and upper motor neuron signs
- wasting of the small hand muscles/tibialis anterior is common
Other features
- doesn't affect external ocular muscles
- no cerebellar signs
- abdominal reflexes are usually preserved and sphincter dysfunction if present is a late feature
*vague sensory symptoms may occur early in the disease (e.g. limb pain) but 'never' sensory signs
Investigations
Management
Riluzole
- prevents stimulation of glutamate receptors
- used mainly in amyotrophic lateral sclerosis
- prolongs life by about 3 months
Respiratory care
- non-invasive ventilation (usually BIPAP) is used at night
- studies have shown a survival benefit of around 7 months
Prognosis
- poor: 50% of patients die within 3 years