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• History should be taken to understand how tremor impacts daily living and
function, to determine if treatment is indicated.
• Activities to ask about include eating, drinking, writing, hygiene, dressing,
work, and hobbies.
• The social disability/stigma and embarrassment with ET can be significant,
so this should be discussed.
• Neuroimaging to measure dopamine uptake (DaTscan) can be done if there
is suspicion of underlying PD.
• Examination of the patient includes assessment of the various parts of the
body that can be affected.
Assessment/Screening
Parkinson's Disease
• There are many red flags that suggest the patient may be developing PD,
which is the diagnosis most often confused with ET.
▶ Aspects of the tremor that suggest PD include unilateral tremor onset and notable
rest tremor.
▶ Rest tremor often appears when the hand is down at the side, so walking should be
part of a tremor evaluation.
▶ Additionally, PD patients should demonstrate bradykinesia, and often rigidity of
the limbs.
▶ Bradykinesia can be assessed by watching the patient do rapid repetitive
movements such as finger tapping, hand opening/closing, and foot tapping.
▶ Patients with PD may have prodromal non-motor symptoms such as hyposmia
and REM sleep behavior disorder, so these should be elicited.
Medications and Other Causes of Tremor
• The medication list should be reviewed carefully since medications such as
stimulants, antidepressants, antipsychotics and many immunosuppressants
can cause tremor.
• While most medications trigger tremor in a predictable dose-related
fashion, there are some, like valproic acid and amiodarone, that can trigger
tremor even after long-standing low-dosage exposure.
• When diagnosing ET, consider ruling out thyroid issues (e.g.
hyperthyroidism) and metabolic disorders (e.g. B-12 deficiency).
• Also consider ruling out dystonic tremor, especially if tremor is present in
or isolated to the head. Dystonia and ET are two movement disorders that
may occur independently or coexist.
Differential Diagnosis
