• Clinical science



Tremors are the most common movement disorder and are defined as rhythmic, involuntary movements of one or more parts of the body. Tremors are classified as resting or action tremor (i.e., postural and intention tremors). Resting tremors typically occur in patients with Parkinson's disease (PD) and usually present as asymmetrical tremors that occur during rest. Postural tremors are usually essential or physiologic. Essential tremors are the most common type of tremor and usually involve the hands and head. They characteristically improve with alcohol consumption. Physiologic tremors occur when holding a position against gravity and are enhanced by increased sympathetic stimulation (e.g., caffeine, anxiety). Intention tremors suggest cerebellar lesions, which typically occur with strokes, trauma, or tumors. Patients present with a coarse hand tremor that is aggravated by goal-directed movements. A combination of tremor types is also possible. The diagnosis of tremors is typically clinical. Further laboratory tests and imaging may be required to determine the underlying condition. Treatment depends on the type of tremor.


Common types of tremors
Resting tremor Action tremor
Postural tremor Intention tremor
Essential Physiologic
Description Pill-rolling Fine Fine Coarse
Etiology Idiopathic Parkinson disease or side effect of neuroleptic medication (caused by a dysfunction of the basal ganglia ) Hereditary Physiological Cerebellar lesion (e.g., stroke, trauma, multiple sclerosis, chronic alcoholism)
Onset At rest With certain postures; worse with voluntary movement With certain postures; enhanced with sympathetic stimulation (e.g., stress) Slow zigzag movement towards a target (“Intention tremor”)
Associated features Rigidity, bradykinesia, postural instability Head tremor; normal neurological examination Normal neurological examination Ataxia, hypotonia, gait instability, difficulties with rapid movements, dysarthria, nystagmus
Improved by Action Alcohol Managing cause of sympathetic stimulation Rest


Resting tremor


Postural tremor

Essential tremor

Physiologic tremor

Orthostatic tremor

  • Epidemiology
    • Rare
    • Sex: >
    • Age of onset: 60 years (usually)
  • Etiology: unknown
  • Clinical features: long periods of standing may lead to:
    • Trembling feeling in the legs
    • Subjective feeling of unstable balance, and falling over
  • Diagnosis
    • Clinical diagnosis: (Synchronized) shaking of the legs may be seen or felt by the examiner.
    • Electromyography of the legs while patient is standing; detection of 13–18 Hz tremor
  • Treatment

Consider an essential tremor in a patient presenting with chronic bilateral hand tremors without further neurological deficits and a positive family history!


Intention tremor


Additional types of tremors