Triple stimulation technique findings in vascular Parkinsonism and Parkinson’s disease

• Clinically, vascular Parkinsonism is difficult to diagnose clearly because this disease is very heterogeneous, and there are currently no biomarkers to diagnose vascular Parkinsonism.
• In triple stimulation technique, TST amplitude ratios reflecting upper motor neuron involvement were significantly different between vascular Parkinsonism and Parkinson’s disease.
• The triple stimulation technique is an effective technique that may provide useful information for differentiating vascular Parkinsonism from Parkinson’s disease.

ObjectiveOne of the predominant clinical features that differentiates vascular Parkinsonism (VP) from Parkinson’s disease (PD) is the pyramidal sign. The triple stimulation technique (TST) is one of the most sensitive methods for comparing upper motor neuron involvement in patients with VP and PD. This study aimed to evaluate the usefulness of the TST as a diagnostic tool for VP.MethodsThirteen VP patients, 18 PD patients and 10 age-matched healthy controls were enrolled in this study. We obtained basic participant demographic information and transcranial magnetic stimulation (TMS) parameters, including the TST amplitude ratio, from all participants. We compared the TMS parameters among the VP, PD and control groups.ResultsThe TST amplitude ratio was significantly lower in the VP group than in the PD and control groups (71.59 ± 11.86 vs. 96.42 ± 5.11 and 97.70 ± 3.82, respectively; p < 0.01). The TST amplitude ratio was positively correlated with scores obtained on the United Parkinson’s Disease Rating Scale-III, which reflects motor function.ConclusionsThe TST is an effective and easy technique that offers improved diagnostic sensitivity in patients with VP by assessing upper motor neuron involvement. The TST may also represent a useful monitoring tool for evaluating disease progression.SignificanceThis study is the first to assess pyramidal involvement in patients with VP using the collision technique.