SIRPID (Stimulus Induced Rhythmic, Periodic, or Ictal Discharges)
New nomenclature for SIRPID is: Stimulus-Induced (SI)Rhythmic Delta Activity (RDA) or Stimulus-Induced Generelized Periodic Discharges (GPD), dependent of the pattern of the discharges. 
- Stimulus Induced Rhythmic, Periodic, or Ictal Discharges (SIRPID)
- Due to cortical and subcortical brain damage (thalamo-cortical dysfunction)
- Often seen after acute brain injury (around 75%)
- Discharges are induced by a tactile stimulus, i.e. touch or pain.
- In critically ill patients
- 50% has (sub)clinical seizures.
- Risk factor for development of status epilepticus.
- Encephalopatic background EEG
- Rhythmic delta discharges after a stimulus, i.e. pain.
- Generalized or focal discharges.
- Lasting seconds to hours
Generalized SIRPIDs after pain stimulus (blue line) (Average)
- ACNS STANDARDIZED ICU EEG NOMENCLATURE v. 2012