Fasciculations
- These are subtle, subcutaneous movements that represent contractions of a motor unit, seen in LMN disease (especially those involving anterior horn cells), but can be entirely benign.
- In LMN lesions they are thought to represent the repetitive discharges of dying motor units.
- Myokymia is the state of nearly continuous fasciculations causing a rippling appearance, associated with demyelinating diseases such as Guillain-Barre and MS.
Patient 1:
This is a middle-aged man who presented with progressive weakness and paresthesias and was subsequently diagnosed with Guillain-Barré syndrome.