Typically the differential of tremor is not broad but does include the following major entities, as well as less common tremor conditions. 
Essential Tremor      Dystonic Tremor        PD Tremor            Functional Tremor  



Actively seek for potential causes of drug induced and enhanced physiological tremor.


Determine whether the tremor is a rest or action tremor (postural, kinetic, or isometric).

Rest tremor is predominantly seen in PD, but is also a presentation of dystonic tremor and may be seen in functional tremor. Although rest tremor is certainly a feature of ET, it is usually only present in advanced ET of long duration. It is important to appreciate that a condition of rest may be difficult to achieve with standard examination, and therefore adjustment of the clinical setting for assessment of rest tremor may be important, as described here:          

Compare ET vs Cervical Dystonia Tremor

Compare ET vs PD Tremor  

Table 1. Comparison of three major tremor types



Downloadable PDF:  Tremor Chart



Table 2. ET vs Cervical Dystonia Tremor




Table 3. ET vs PD Tremor  





















































































































































































































































































           POSTURAL TREMOR     



  1. Examine the patient with arms relaxed, ideally on the arms of a chair with their forearms supported and hands hanging down, or with their hands on their lap, half pronated.
    If there is uncertainty, the patient may additionally be examined in the supine position, with the hands by their side lying on the
    bed, or the hands may be allowed to rest on the abdomen, or have the elbows be supported by a pillow, allowing the hands to be completely relaxed.
  2. Arms may be examined for rest tremor while walking or lying.
  3. Legs can be assessed while the patient is seated or lying down.  When lying down, the patient lies supine with their feet hanging off the end of the examination couch.
  4. The patient should be asked to close their eyes and count backwards from 100. This distraction task often brings out tremor. 
  1. Examine the outstretched arms, palms down, and fingers open.
  2. Ask the patient to close their eyes and count backwards.
  3. Ask patient to adopt the wing-beat position with the hands facing one another in the midline, and then to slowly supinate and pronate the arms, looking for position specificity of the tremor.
  4. If postural tremor is present during sustained arm extension, the examiner should assess the following:
    -Which joints are involved (eg, elbow, wrist, metacarpophalangeal joints)
    -In what direction/axis is the tremor? (eg, for the wrist, flexion-extension, pronation-supination)
    -Whether the tremor is accompanied by abnormal postures.
  1. Examine the patient’s arms during movement by doing the finger-nose test, looking for tremor during movement (kinetic tremor) and any clear worsening at the end points (intention tremor).
  2. Specifically assess response of rest tremor to an action, and examine for re-emergent tremor.
  3. Pour water between cups, draw spirals, or write a sentence.
  4. Compare severity of kinetic tremor to that seen during sustained posture.
  5. Note whether dystonic movements or postures are present (eg, do some of the fingers flex, extend, or twist during the finger-nose-finger manoeuvre?).
  6. Spiral drawing
    NB patient's hand must not rest on paper