Features differentiating essential tremor from other disorders
| Diagnosis | Tremor type | Frequency | Unilateral/bilateral | Areas involved | Alcohol responsive? | Other features |
|---|---|---|---|---|---|---|
| Essential tremor | Postural, intention | 4–12 Hz | Usually bilateral | Hands, head, legs, voice, face (jaw), neck and trunk | Commonly (50–90% of patients) | May have mild cerebellar signs and eye movement abnormalities |
| Enhanced physiological | Postural, intention | 8–12 Hz | Bilateral | Hands | Maybe | Usually associated with stress, caffeine, medications |
| Parkinson’s disease | Rest | 3–6 Hz | Usually starts unilateral | Hands, feet, lips (head is seldom involved) | No | Bradykinesia, rigidity, postural instability |
| Cerebellar | Intention, postural | <5 Hz | Unilateral or bilateral (depending on which side cerebellum is affected) | Usually head/upper part of the body | No | Other findings of cerebellar dysfunction |
| Dystonia | Postural | <7 Hz | Bilateral | Head | Usually no—alcohol may make symptoms worse | Sensory trick |
| Psychogenic | Rest and/or postural (intermittent, can change in frequency or amplitude) | 4–12 Hz | Unilateral or bilateral | Arms, legs, head | No | Usually sudden onset; exhausting for patients Distractable, co-activation sign |
| Orthostatic tremor | Postural | 13–18 Hz | Bilateral | Usually legs, can occur in arms and trunk as well | No | Auscultation by stethoscope |
| Wilson’s disease | Postural, intention “wing beating” | 4–6 Hz | Bilateral | Arms, legs, trunk | No | Other associated findings: liver disease, incoordination, dysarthria, dystonia, spasticity, Kayser–Fleisher rings |
| Task specific tremor | Task-specific | 4–8 Hz | Unilateral | Hands | No | Tasks may include writing, playing a musical instrument, playing sports, etc |
| Holmes’ s tremor (“rubral tremor”) | Rest, postural, intention | 2–5 Hz | Unilateral or bilateral depending on location of lesion | Arms, trunk | No | Associated cerebellar signs (red nucleus). Usually occurs 4 weeks to 2 years after lesion |
| Neuropathic tremor | Postural, intention | 3–6 Hz | Bilateral | Arms, legs (where neuropathy is present) | No | Associated with an underlying neuropathy, demyelinating most common |
| Fragile X-associated tremor/ataxia syndrome (FXTAS) | Intention most common (activated by writing). Can see mixture of intention and rest or rest alone | 3–5 Hz | Unilateral or bilateral | Arms | No | Males >50 years old with tremor, ataxia, cognitive and behavioural problems. Fragile X-mental retardation 1 (FMR 1) gene premutation. Maternal inheritance. Family history of mental retardation |