Background
- Uncurable motor neuron degenerative disease
- May present to ED as:
- Abnormal gait (falls)
- "Radiculopathy" (eps. cervical)
- "Footdrop"/"Wristdrop" Saturday night palsy
- Bulbar "event" (e.g. slurred speech or aspiration)
- M:F = 2:1, any age (incidence rising with age)
Clinical
Symptoms
- 80% present with limb weakness ("amyotrophy" = muscle fibre atrophy), NB foot drop or loss of finger dexterity
- 20% with bulbar symptoms, slurred speech, poor swallow, aspiration
- Initial flaccid, then ±spastic cramps
- Later cognitive and emotional fluctuations
Signs
- Mixed UMN and LMN signs in different body regions
- No sensory signs in ED
Differential Dx
Very early presentation may "mimic" others:
- "Falls" - always check gait
- Bulbar TIA/Stroke
- Brachial neuritis
- GBS or Miller Fischer (but GBS has sensory symptoms and different progression)
- Botulism (afebrile, descending, flaccid paralysis)
- HypoKalaemia or other metabolic derangement
Investigations (in-patient)
- EMG - Normal sensory, abnormal motor conduction
Management
- If suspected, admit neurology for workup and management plan
- Consider, respiratory support, analgesia etc