Definition: rhythmic involuntary movement.
- precipitant (resting, movement, postural)
- rate (slow 4–6 Hz) or fast (6–12 Hz)
- amplitude (fine or coarse)
- distribution (trunk or limbs, distal or proximal)
May be exaggerated by anxiety, hyperthyroidism, phaeochromcytoma.
- 6–12 Hz
- distal (usu. upper limbs)
May improve with EtOH and β-blockers.
- Familial (autosomal dominant)
- Benign essential (no FHx)
- slow: 4–6 Hz
- 4–6 Hz
- both proximal and distal