Age at test: 40
With PD patients with stimulators, the interest is in documenting post-operative improvement with the sub-thalamic nucleus stimulation bilaterally. The clear effect of the STN stimulation is in reducing the tremor during stance as illustrated in first set of traces below for the task of standing eyes closed on foam. Tremor measurements at 5 Hz indicate a considerable improvement with a four-fold reduction in sway velocity amplitudes (see spectra next to time traces). Other tasks such as walking with eyes closed are performed faster but only with a slight improvement in trunk sway. This confirms the general impression that STN stimulation improves tremor but not axial instability in PD patients. The task results illustrated for the STN stimulation on and off stimulation also suggest which measures need careful monitoring when SwayStar is used to screen for the presence of PD.
Stimulation off, standing eyes closed on foam
Stimulation on, standing eyes closed on foam
Stimulation off, walking 3 m eyes closed
Stimulation on, walking 3 m eyes closed.