EEG Flashcards
What frequency are alpha waves?
8-12 Hz
When are alpha waves typically seen?
Awake but eyes closed
What frequency are beta waves?
13-30 Hz
When are beta waves typically seen?
- Awake and attentive with eyes open
- REM sleep
What frequency are gamma waves?
> 30 Hz
When are gamma waves typically seen?
Wide-awake and concentrating
What frequency are delta waves?
0.1-4 Hz
When are delta waves typically seen?
Stage IV of NREM sleep
What frequency are theta waves?
4-8 Hz
When are theta waves typically seen?
Stage and II of NREM sleep
When are Vertex waves (V waves) seen on EEG?
Stage 1 of REM sleep
When are sleep spindles seen on EEG?
Stages 2-4 of NREM sleep
When are K complexes seen on EEG?
Stages 2-4 of NREM sleep
When is slow activity seen on EEG?
Nonspecific sign of disturbed brain function
When are paroxysmal discharges seen on EEG?
Epileptiform discharge
When are sharp waves (rising between 70-200 ms) seen on EEG?
Interictal epileptiform discharge
When are spikes (sloped peak of <70 ms) seen on ECG?
Interictal epileptiform discharge
When is spike and wave activity at a frequency of 3/s seen on EEG?
- Absence seizures
- Myoclonic twitches
When is spike and wave activity at a frequency of <3/s seen on EEG?
Lennox-Gastaut syndrome
When are polyspikes and polyspike-wave complexes seen on EEG?
- Generalised epilepsy
- Juvenile myoclonic epilepsy
- Progressive myoclonic epilepsies
- Absence seizures
When are periodic sharp wave complexes (frequency of 1-2 Hz) seen on EEG?
Early stages of sporadic CJD
When are hypsarrhythmias seen on EEG?
West syndrome (Infantile spasms)
