Tremor Meaning

Tremor – colloquially known as shaking – (ICD-10 R25.1-: Tremor, unspecified) refers to involuntary rhythmic twitching of muscle groups (of one or more parts of the body). The hands are often affected, but the whole body can also be affected.

Tremor is classified using the Movement Disorder Society’s classification proposal according to the following criteria:

  • Activation condition (rest, action, holding, undirected movement, target movement).
  • Frequency (low frequency: 2-4 Hz, medium frequency: 4-7 Hz, high frequency: > 7 Hz).
  • Intensity or amplitude
    • Fine-beat tremor
    • Medium-beat tremor
    • Coarse-beat tremor
  • Duration of the disease
  • Heredity
  • Other symptoms and medical history useful in elucidating the etiology (cause) of the underlying disease (extrapyramidal symptoms such as akinesia (high-grade lack of movement) or rigor (muscle rigidity) or polyneuropathies (diseases of the peripheral nervous system), etc.).

A clearly visible tremor can be a symptom of various diseases.

The following forms of tremor are distinguished (for details, see “Symptoms – complaints”):

  • Action tremor
    • Holding tremor
    • Intention tremor
    • Isometric tremor
    • Kinetic tremor (motion tremor)
  • Dystonic tremor (moderate-frequency holding and movement tremor around 5-8 Hz).
  • Essential tremor (ET) (medium-beat, medium-frequency holding and movement tremor around 5-8 Hz) – occurs without an identifiable underlying neurological disease; most common form of tremor (about 1% of the population).
  • Holmes tremor (synonyms: rubral tremor, midbrain tremor, myorhythmia, Bendikt syndrome) (low frequency (2-5 Hz) and coarse-beat amplitude) – usually unilateral resting, holding and intention tremor.
  • Neuropathic tremor (4-8 Hz and coarse-beat amplitude) – centrally generated tremor; commonly occurs in patients with: hereditary motor and sensory neuropathy (HMSN) of the demyelinating type (CMT 1) or in inflammatory neuropathies (e.g., CIDP, neuropathy in MGUS)
  • Orthostatic tremor (OT; nonvisible, high-frequency tremor (12-20 Hz; usually at 16 Hz).
  • Parkinsonian tremor (mid-frequency: 4-7 Hz).
  • Pathological tremor
  • Physiological (without disease value) tremor (fine-beat, high-frequency (7-12 Hz).
  • Psychogenic tremor
  • Resting tremor
  • Enhanced (increased) physiological tremor
  • Cerebellar tremor (slow frequency (2-5 Hz) and large amplitude).

The most common are enhanced physiological tremor, essential tremor and Parkinsonian tremor.

Tremor can be a symptom of many diseases (see under “Differential diagnoses”).

Sex ratio: Men and women are equally affected by essential tremor.

The prevalence of essential tremor varies widely in the literature (between 0.014 and 20.5%). Approximately 4.6% of people over the age of 65 suffer from essential tremor.The prevalence of enhanced physiological tremor is 9.5% in the over-50 age group.

Frequency peak:Essential tremor occurs predominantly in young adulthood. Children are less commonly affected.

Course and prognosis: The tremor can affect the life of the affected person to a greater or lesser extent. Even eating, drinking and writing are difficult or impossible in severe forms of tremor. Many of those affected withdraw from public life. If the tremor occurs as a symptom of a disease, its treatment is the main focus. The essential tremor is slowly progressive. In between, there may be phases with constant symptoms. In other cases, the tremor has an approximately constant intensity throughout life.