PMC6449652_01
Seizure discharge with isolated nostril myoclonus. The EEG recorded in a bipolar montage (red indicates right hemisphere, blue indicates left hemisphere). Please note reduced gain settings as indicated by the gain measure in the bottom left. The EEG reveals high amplitude anteriorly dominant spike-wave discharges without clear lateralisation. Aux 5-7 channels seen inferiorly are EMG channels, revealing a time-locked EMG activation synchronous with electrocortical discharges.
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These seizures were more heterogenous in their electrographic patterns but typically consisted of between 1 and 8 s of generalised spike or doublet spike-wave discharges maximal over the anterior regions (Fig. 1). The semiology in most instances took the form of isolated myoclonus ("flaring") of the nostrils, which was time-locked to the electrical spike discharges (Fig. 1).
Isolated spike-wave discharge with a single isolated nostril myoclonus. The EEG recorded in an average montage (red indicates right hemisphere, blue indicates L hemisphere, black indicates midline). Please note reduced gain and timebase settings as indicated by the gain measure in the bottom left. As is seen from this figure, the independent spike-wave discharge maximal anteriorly correlates with isolated EMG activation indicating nostril myoclonus.
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Furthermore, on two or three occasions isolated high amplitude spike or doublet spike-wave discharges revealed single flares of the nostrils (Fig. 2).