Parkinson disease vs Essential tremor
How to tell Parkinson disease and Essential tremor apart when a board question makes them look alike.
Step 2 CK pairs are in open beta while clinical review finishes. Spot an issue? Tell us.
Rest tremor that fades with voluntary movement points to Parkinson disease.
Side by side
An asymmetric 4 to 6 Hz resting pill-rolling tremor with bradykinesia and cogwheel rigidity supports Parkinson disease.
A bilateral 6 to 12 Hz action and postural tremor without bradykinesia supports essential tremor.
Nigrostriatal dopamine neuron loss in the substantia nigra reduces basal ganglia motor facilitation.
Cerebellothalamic circuit dysfunction produces kinetic tremor without dopaminergic cell loss.
DaTscan can show reduced striatal dopamine transporter uptake in Parkinson disease, and exam shows decrementing finger taps with rigidity on passive movement.
Neurologic exam is otherwise normal in essential tremor, tremor amplitude increases with goal-directed movement, and handwriting often shows large tremulous script rather than micrographia.
The trap
Older adults with severe action tremor are mislabeled as Parkinson disease and started on levodopa unnecessarily. Absence of bradykinesia and rigidity with clear postural tremor supports essential tremor and first-line propranolol or primidone instead.
The repair move
Next best step: perform focused neurologic exam for bradykinesia and rigidity, confirm resting versus action tremor pattern, and start carbidopa-levodopa 25/100 mg three times daily when functional impairment from Parkinson features is present. Use propranolol 40 mg twice daily or primidone for isolated essential tremor.
Try a free question
CoreA 71-year-old woman has bilateral hand tremor when writing and holding a cup, but none at rest. She has no rigidity and normal gait. What is the next best step in management?
Show answer and explanation
Answer: A. Start propranolol therapy. Isolated action tremor without parkinsonian signs is essential tremor and first-line therapy is propranolol or primidone.
Why the other choices are tempting
- B. Wrong. Levodopa is for Parkinson disease with bradykinesia and rigidity.
- C. Wrong. No focal neurologic deficits suggest an acute intracranial lesion.
- D. Wrong. Dopamine blockers can worsen parkinsonism and are not tremor first-line therapy.
- E. Wrong. Functional limitation from essential tremor warrants treatment.
Flashcards
Tap a card to flip it.
Which tremor pattern most strongly favors Parkinson disease over essential tremor?
An asymmetric resting tremor with bradykinesia and rigidity favors Parkinson disease.
What bedside finding supports essential tremor instead of Parkinson disease?
Bilateral postural and kinetic tremor without bradykinesia or cogwheel rigidity.
Quick answers
What is the fastest way to tell Parkinson disease from Essential tremor?
Rest tremor that fades with voluntary movement points to Parkinson disease.
What is the key clue for Parkinson disease?
An asymmetric 4 to 6 Hz resting pill-rolling tremor with bradykinesia and cogwheel rigidity supports Parkinson disease.
What is the key clue for Essential tremor?
A bilateral 6 to 12 Hz action and postural tremor without bradykinesia supports essential tremor.
What is the common trap with Parkinson disease vs Essential tremor?
Older adults with severe action tremor are mislabeled as Parkinson disease and started on levodopa unnecessarily. Absence of bradykinesia and rigidity with clear postural tremor supports essential tremor and first-line propranolol or primidone instead.