Parkinson's Tremor vs Dyskinesia: What's the Difference?

When you have Parkinson’s disease, experiencing involuntary movements can be frustrating and confusing. It can be difficult to tell the difference between a Parkinson’s tremor and the twitching that comes from your medications, known as levodopa-induced dyskinesia (LID). The key difference lies in the type of movement and when it happens in relation to your medication schedule. A Parkinson’s tremor is typically a rhythmic shaking that happens when your medication levels are low, while dyskinesia consists of fluid, non-rhythmic, writhing movements that happen when your medication levels are high ^[1][2].

Understanding these differences is crucial because they mean opposite things for your treatment. A tremor usually means your brain needs more dopamine, while dyskinesia often means your brain is receiving a bit too much dopamine at that moment ^[2][3]. Important: While tracking these signs is helpful, never adjust your levodopa dosage on your own. Always consult your neurologist before making any changes to your medication schedule.

Recognizing a Parkinson’s Resting Tremor

A resting tremor is a core symptom of Parkinson’s disease ^[1]. It is often one of the first signs of the condition and indicates that your brain does not have enough dopamine ^[4][5].

• What it looks like: A tremor is rhythmic and repetitive, like a metronome or a clock ticking. It often looks like “pill-rolling” between your thumb and index finger ^[1].
• When it happens: It typically occurs when you are at rest, and your limbs are relaxed ^[1]. The shaking usually decreases or stops completely when you start to use that body part to do something (like reaching for a cup) ^[6].
• What it means for your medication: Tremors typically happen during your “Off” periods—when the effects of your previous dose of levodopa are wearing off, and the dopamine levels in your blood are dropping ^[5][7]. This is a sign of under-medication ^[2]. Note that while levodopa often improves tremors, some resting tremors can be medication-resistant, meaning they may not entirely disappear even when your medication is working well.

Recognizing Levodopa-Induced Dyskinesia (LID)

Dyskinesia is a complication that can develop after you have been taking levodopa for several years ^[2]. About half of people with Parkinson’s will experience some degree of dyskinesia within five years of starting treatment ^[8].

• What it looks like: Unlike a rhythmic tremor, dyskinesia is non-rhythmic, fluid, and writhing ^[1][2]. It can look like fidgeting, dancing, swaying, or twitching ^[2].
• When it happens: Dyskinesia can happen when you are resting or moving. It is most commonly “peak-dose” dyskinesia, meaning it occurs when your medication is fully kicked in and dopamine levels are at their highest (your “On” period) ^[9][7]. A less common form, called “diphasic dyskinesia,” can occur specifically as your medication is kicking in or wearing off.
• What it means for your medication: Peak-dose dyskinesia indicates an over-stimulation of dopamine receptors in the brain ^[10][2]. As Parkinson’s progresses, the “window” of time where your medication works well without causing dyskinesia becomes narrower ^[11][12].

It is also worth noting that both tremors and dyskinesia can temporarily worsen during times of stress, anxiety, or excitement. This does not necessarily mean your medication has stopped working.

How to Tell Them Apart: A Quick Guide

Managing the Balance

Balancing these two extremes is one of the main goals of Parkinson’s care. If it is incorrectly assumed that dyskinesia is a tremor and a higher medication dose is taken, the dyskinesia will likely worsen. If a tremor is confused for dyskinesia and the medication is reduced, you may experience severe stiffness and slowness.

Doctors manage this tricky balance through several strategies:

• Dose optimization: Taking smaller doses of levodopa more frequently to avoid the high peaks that cause dyskinesia and the low valleys that cause tremors ^[13][14].
• Extending the medication: Using other oral medications (like COMT or MAO-B inhibitors) or extended-release levodopa to keep dopamine levels smooth and steady ^[15][3]. For some, continuous levodopa intestinal gels or infusions can be used to prevent fluctuations in medication delivery ^[13][16].
• Add-on therapies: Some medications, such as amantadine, can specifically target and reduce dyskinesia without worsening your “Off” symptoms ^[8][3].
• Surgical options: For some, procedures like deep brain stimulation (DBS) can dramatically reduce dyskinesia while controlling tremors ^[17][18].

Keeping a symptom diary noting the exact times you take your medication and when your movements start and stop will be the most helpful tool for you and your doctor to figure out exactly what kind of movement you are having. A simple entry might look like this:

• 10:00 AM - took levodopa dose.
• 11:15 AM - started swaying and fidgeting while watching TV.
• 1:30 PM - fidgeting stopped, rhythmic shaking in left hand returned.