Objective: To longitudinally describe the course and clinical characteristics of tremor in Parkinson Disease (PD) over a seven-year follow up.
Background: Tremor is a cardinal symptom of PD and one of the most troublesome manifestations. Dopaminergic medications may have a suboptimal effect on tremor, compared to other cardinal symptoms.
Method: 423 patients recruited in the Parkinson Progressive Markers Initiative (PPMI) were considered. MDS-UPDRS III scores were used to evaluate tremor. After baseline, we evaluated yearly follow-ups for the first seven years. At each assessment we analyzed: the pattern and clinical severity of rest, postural, and kinetic tremors according to MDS-UPDRS III scores; the response of tremors to dopaminergic therapy.
Results: 96.9% of patients exhibited tremor during the first seven years. The most common tremor pattern was the combination of rest, postural and kinetic tremors (about 30% of the cohort at each assessment); rest tremor was the most frequent type of tremor in the cohort (65-70% of tremulous patients at each assessment). Mean scores of the three types of tremors tended to worsen and to spread from unilateral to bilateral (bilateral: 6.7% of the cohort at BL vs 31.5% at 7y). The proportion of patients with a MDS-UPDRS tremor score >2 in a single upper limb increased from 6% to 22%. Tremor response to dopaminergic therapy was documented at each assessment by a significant decrease in MDS-UPDRS tremor scores from the OFF to the ON state. The proportion of tremulous patients who showed a full response (75-100% improvement) to dopaminergic therapy increased over time, e.g. for rest tremor from 17.4% (1y) to 45.6% (7y). Conversely, the percentage of non-responders (improvement <25% or worsening) decreased over time for all types of tremor, e.g. from 49.3% of patients with rest tremor (1y) to 25.6% (7y).
Conclusion: Almost all patients experienced tremor over the 7-year follow up. The proportion of patients with tremor decreases over time, but tremors tend to spread bilaterally and to show increasing scores. A reduction in mean tremor scores from OFF to ON is always evident at the cohort level. However, a non-negligible proportion of patients is non-responsive. A complete response of rest tremor is shown in less than 50% of patients at all time points. These data show that along dopaminergic agents, other medications are needed to tackle tremor in PD.
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To cite this abstract in AMA style:J. Pasquini, N. Pavese. The course of tremor in de novo PD: 7 year longitudinal analysis [abstract]. Mov Disord. 2021; 36 (suppl 1). https://www.mdsabstracts.org/abstract/the-course-of-tremor-in-de-novo-pd-7-year-longitudinal-analysis/. Accessed December 5, 2023.
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