Tremor | Description |
Essential tremor | Bilateral postural or kinetic tremor of the hands and forearms (≥4 Hz; usually 6 to 12 Hz) or isolated head tremor without evidence of dystonia. Absence of other neurologic signs or recent trauma preceding the onset of tremor. Can be asymmetric. |
Physiologic tremor | Enhanced physiologic tremor. High frequency (10 to 12 Hz), presence of known cause (eg, medications, hyperthyroidism, hypoglycemia). |
Parkinson disease | Rest tremor, unilateral at onset. Can be mixture of rest and action tremors; occasionally action tremor alone. Asymmetry sustained when bilateral. Leg or foot tremor more common than with essential tremor, usually does not produce head tremor. Frequency 4 to 6 Hz. |
Orthostatic tremor | Postural tremor in the torso and lower limbs while standing; may also occur in the upper limbs. Suppressed by walking. Tremor is high frequency (14 to 20 Hz) and synchronous among ipsilateral and contralateral muscles. |
Cerebellar tremor | Postural, intention, or action tremor. Relatively low frequency (3 to 4 Hz). Associated with ataxia and dysmetria. |
Neuropathic tremor | Variable tremor type and frequency, usually postural and kinetic tremor in the involved extremities. Other signs of peripheral neuropathy present. |
Rubral or midbrain tremor | Mixture of rest, postural, and intention tremor with frequency of 2 to 5 Hz. Always associated with signs of brainstem or cerebellar damage. |
Dystonic tremor | Action tremor, usually postural or task-specific, in a body part that is affected by dystonia. Usually slow, irregular, and jerky. Common examples are head and/or arm tremor due to cervical dystonia. May be responsive to alleviating maneuvers (sensory trick). |
Functional tremor | Can affect any body part with rest, action, or both. Variable in direction, amplitude, and frequency. Distractible and entrainable. When physically suppressed by examiner, tremor may appear in another limb. |