14 & 6Hz positive spikes coinciding with PLEDs

We describe the coincidence of 14 & 6Hz positive spikes with PLEDs in a patient with clonic status epilepticus of the left upper extremity and the persistence of 14 & 6Hz positive spikes after cessation of status.

Digital video-EEG recordings were performed using 32-channel EEG equipment (XLTEK, Canada) with all electrodes of the international 10-20 system and additional anterior temporal electrodes in a patient during clonic status epilepticus and 2 months later after cessation of status.

The initial EEG during clonic status epilepticus showed right hemispheric PLEDs and right lateral temporal 14 & 6Hz positive spikes in between the PLEDs. Follow up EEG recording 2 months later after cessation of status revealed an absence of PLEDs, a continuous slowing over the right hemisphere and the occipital background of 7Hz. Right lateral temporal 14 & 6Hz positive spikes were recorded in the same frequency and the same localization as in the previous status EEG.

This case demonstrates that a hemisphere which is in a status epilepticus as clinically reflected by clonic status of the left hand and PLEDs in the EEG is still capable to produce a benign variant pattern like 14 & 6Hz positive spikes.

The generator of 14 & 6Hz positive spikes may still persist despite the presence of severe structural and epileptogenic lesions in the same hemisphere.