Box 1: Classification of tremor in children5,6,12
Type of tremorFrequency (Hz)OccurrenceExamples
RestLow–medium (3–6)While limb is relaxed and supported against gravity

  • Juvenile Parkinson disease

  • Medication induced (e.g., use of lithium, neuroleptics, anticonvulsants, immunosuppressants or β-adrenergic antagonists)

  • Wilson disease

ActionDuring voluntary muscle contraction
PosturalMedium–high (4–12)While limb is held in position against gravity

  • Physiologic tremor

  • Essential tremor

  • Drug withdrawal

  • Neuropathy

  • Metabolic disturbance

Kinetic
 Simple kineticVariable (3–10)During simple limb movements

  • Essential tremor

  • Enhanced physiologic tremor

 IntentionLow (< 5)During target-directed limb movements

  • Cerebellar lesion (e.g., tumour, trauma, multiple sclerosis or stroke)

  • Medication induced (e.g., use of lithium, neuroleptics, anticonvulsants, immunosuppressants or β-adrenergic antagonists)

  • Alcohol induced

 IsometricMedium (4–6)During muscle contraction against stationary objects

  • Essential tremor

  • Enhanced physiologic tremor

  • Juvenile Parkinson disease

 Task specificVariable (4–10)During task-specific limb movements

  • Handwriting tremor

  • Musician’s tremor