Category: Tremor
Objective: We aimed to identify clinical characteristics that are useful for differentiating dystonic tremor (DT) and Parkinson’s disease (PD).
Background: DT is often challenging to diagnose and can be misdiagnosed as PD. These cases are referred to as SWEDDs (Scans Without Evidence of Dopaminergic Deficit). The diagnosis of DT is particularly challenging when dystonia is mild or complicated by parkinsonism.
Method: We conducted detailed neurological evaluations and tremor analyses using triaxial motion sensors on DT and PD patients who fulfilled the MDS diagnostic criteria (Bhatia et al. Mov Disord 2018; Postuma et al. Mov Disord 2015). The Mann-Whitney test was used for between-group comparisons.
Results: The cohort comprised 30 DT and 21 PD patients (age at examination: 69.2 ± 10.8 vs. 64.1 ± 13.2 years old, p = 0.147; male sex 27% vs. 33%, p = 0.620). Compared with the PD group, the DT group exhibited a significantly lower amplitude of rest tremor (p = 0.002) and a significantly higher amplitude of kinetic tremor (p < 0.001). The amplitude of postural tremor did not significantly differ between the groups. There were no significant differences between the groups in the frequency of rest, postural, and kinetic tremor. Task specificity, sensory tricks, and other findings suggestive of DT were almost exclusively seen in the DT group but were not sufficiently sensitive to diagnose DT alone. However, the pattern of tremor intensity being greater during kinetic activities than during posture had a sensitivity of 83% and a specificity of 81% for differentiating DT from PD.
Conclusion: Findings suggestive of dystonia, such as task specificity and sensory tricks, may be insensitive when differentiating DT and PD. The pattern of tremor severity mentioned above may offer better sensitivity and specificity for differentiating DT from PD than dystonic features alone.
To cite this abstract in AMA style:
T. Tsuboi, K. Sawada, S. Hoshino, M. Higuchi, M. Muto, Y. Ito, M. Hashida, T. Ishizaki, S. Kato, D. Nakatsubo, T. Tsugawa, S. Maesawa, M. Sato, K. Hiraga, T. Uematsu, D. Tamakoshi, D. Fukushima, M. Suzuki, R. Saito, M. Katsuno. Clinical differentiation between dystonic tremor and Parkinson’s disease based on tremor characteristics [abstract]. Mov Disord. 2024; 39 (suppl 1). https://www.mdsabstracts.org/abstract/clinical-differentiation-between-dystonic-tremor-and-parkinsons-disease-based-on-tremor-characteristics/. Accessed October 10, 2024.« Back to 2024 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/clinical-differentiation-between-dystonic-tremor-and-parkinsons-disease-based-on-tremor-characteristics/