Video 1
Example of Tic. In this video, the patient builds tension voluntarily, but the movement is “involuntary”.
Video 2
Examples of Voluntary Movements. In this video, the patient makes voluntary movements attempting to mimic the tics.
Figure 1
Electromyography of Voluntary Movement and Movement after Tension Buildup. Single traces from EMG recordings from both reported voluntary (A) and those after tension buildup (B). EMG is shown for cervical and thoracic paraspinal muscles, as well as left sternocloidomastoid (SCM).
Figure 2
Back-averaging to Assess the Presence of the Bereitschaftspotential during Each Movement Type. Average traces from simultaneous EEG and rectified EMG recordings from both reported voluntary and tic-like involuntary movements. EMG is shown for cervical and thoracic paraspinal muscles, as well as left sternocloidomastoid (SCM). Markers were manually placed at the onset of each movement, and all movements were subsequently averaged to produce a single trace. A Bereitschaftspotential (BP) is visible starting roughly ~500 ms prior to movement onset (0 ms) in the case of the voluntary movement (A), but not during the movement occurring after the tension buildup (B).