Spike or not?

Jun 29, 2025

Is the arrowed wave?

1. An electrostatic artefact in sleep

2. A generalised spike, primarily electro positive over the posterior head regions, during sleep

3. A very sharply contoured vertex wave

4. A frontally predominant, generalised spike during sleep

5. Brief EMG artifact during sleep

 

In the example above, the discharge has a "biological field" and may be explained by the discharge that is primarily electro positive over the posterior head regions or electro-negative over the frontal-central regions.

 

 

 

 

However, while the discharge has a field suggestive of cortical origin, this is a "pseudo-field" as the discharge, on morphological grounds, is an artefact, given its sharp, pixelated appearance. Such electrostatic artefacts are common in sleep and the source of these is often impossible to discern from looking at the EEG and the video.

 

Bottom line?
As stated in an earlier post, artefacts may have a "field" suggestive of an inter-ictal epileptiform discharge.