Table 1.

Presence and onset time of the Bereitschaftspotential in functional jerks, myoclonus and tics (data derived from van der Salm et al., 2012).

	Presence of BP preceding jerky movements	Onset time BP (ms)
Functional jerks	47–86 %	1195 (700–2410)
Myoclonus	0 %	–
Motor tics	43 %	915 (510–1700)

Onset time is reported as median (range).