Tremor

INDEX

Tremors are usually described by the context in which they appear: rest or action.  Most tremor types, however, are action tremors that occur during voluntary contraction of a muscle.

Rest vs Action Tremor (Examination Techniques)

  1. Rest tremor: occurs in a body part that is relaxed and completely supported against gravity (e.g., resting an arm on a chair).
  2. Action tremor: subdivided into:
    • Kinetic
      • Simple kinetic: During non-target/goal-directed movements e.g., finger tapping. May persist during voluntary, goal-directed movement without an increase in amplitude during the terminal phase
      • Goal-directed: during target reaching= “intention tremor”. (In this case, a position-specific tremor or a postural tremor at the initiation or end of a movement must be excluded).
      • Task-specific kinetic: During a specific skilled, goal-oriented task, such as writing or speaking.
    • Postural: voluntarily maintaining posture
      • Position independent
      • Position dependent: only occurring during the maintenance of certain postures
    • Isometric: During a voluntary muscle contraction that is not accompanied by any movement.
                  A subtype is isometric orthostatic tremor: During stance or stance phase of walking e.g. standing, walking.

Note that the terms action and kinetic tremor are frequently used interchangeably, but actually have different meanings.

 

 

 

 

 

 

 

 

 

 

 

 

Activation  conditions1.  

From: Bhatia KP, Bain P, Bajaj N, et al. Consensus Statement on the classification of tremors. From the task force on tremor of the International Parkinson and Movement Disorder Society. Mov Disord. 2018;33(1):75-87.

 

References

1. Bhatia KP, Bain P, Bajaj N, et al. Consensus Statement on the classification of tremors. from the task force on tremor of the International Parkinson and Movement Disorder Society. Mov Disord. 2018;33(1):75-87. doi:10.1002/mds.27121.