Appendix 1—figure 4. SNIC Onset in rats. There were no unequivocal examples of SNIC onset in our human data.

However, our group recently published data from the tetanus toxin model in rats that has excellent SNIC onsets (Crisp et al., 2020). Shown are data from two rats, which were shown in Figure 5 of that paper (see that work for details on experimental procedures). Both animals have clonic bursts, and in the presence of such discharges the dynamotype is characterized by the inter-clonic interval, rather than the fast runs of spikes within the burst (Jirsa et al., 2014; Bauer et al., 2017). In both cases the seizure begins with increasing ISI and essentially constant amplitude. Onset Classification: DC shift: no. Amplitude increasing: no. ISI decreasing: yes, therefore SNIC onset. Note, there is sometimes a continuum between some of the bifurcations; here, the clonic bursts have some characteristics of a DC shift, but since they all return to baseline before the next burst this is not considered a sustained DC shift. Additional details are discussed in Crisp et al., 2020. Offset Classification: Seizure offset is not seen in this view.