QUESTIONS AND CORRECT ANSWERS WITH RATIONALES
ALREADY GRADED A+
1. Which electrode placement system is commonly used in EEG recording?
☑ A. 10–20 system
B. 12-lead system
C. 5-lead system
D. Monopolar cardiac system
Rationale: The 10–20 system standardizes electrode placement for scalp EEG recording.
2. What is the primary frequency range of delta waves?
☑ A. 0.5–4 Hz
B. 4–8 Hz
C. 8–13 Hz
D. 13–30 Hz
Rationale: Delta waves are slow waves typically seen in deep sleep or in brain pathology.
3. Which EEG pattern is most commonly associated with generalized tonic-clonic
seizures?
☑ A. Generalized spike-and-wave discharges
B. Focal slowing
C. Alpha attenuation
D. Beta bursts
Rationale: Generalized tonic-clonic seizures often produce generalized spike-and-wave
discharges on EEG.
4. What is the typical frequency of alpha waves in an adult at rest with eyes
closed?
☑ A. 8–13 Hz
B. 0.5–4 Hz
,C. 4–7 Hz
D. 13–30 Hz
Rationale: Alpha waves are dominant in the posterior regions of awake adults at rest with eyes
closed.
5. Which EEG montage uses one electrode as a common reference for all others?
☑ A. Referential montage
B. Bipolar montage
C. Laplacian montage
D. Average reference
Rationale: In a referential montage, each active electrode is compared to a single reference
electrode.
6. Which artifact is characterized by rhythmic spikes over frontal electrodes and
increases with eye closure?
☑ A. Eye blink artifact
B. Muscle artifact
C. Electrode pop
D. 60 Hz electrical artifact
Rationale: Eye blinks produce frontal slow wave deflections that can mimic EEG abnormalities.
7. Which EEG rhythm is most prominent during REM sleep?
☑ A. Theta and mixed frequency activity
B. Delta waves
C. Alpha rhythm
D. Spindles only
Rationale: REM sleep shows low-voltage mixed frequency EEG activity resembling
wakefulness.
8. What is the primary clinical significance of interictal epileptiform discharges?
☑ A. Indicator of increased seizure susceptibility
B. Diagnostic of stroke
C. Sign of encephalopathy
,D. Normal variant
Rationale: Interictal spikes and sharp waves suggest cortical irritability but do not always
indicate an active seizure.
9. Which electrode type is most commonly used for routine scalp EEG?
☑ A. Cup electrodes
B. Needle electrodes
C. Depth electrodes
D. Subdural grids
Rationale: Cup electrodes are non-invasive, standard for surface EEG recording.
10. Which frequency range defines beta waves?
☑ A. 13–30 Hz
B. 8–13 Hz
C. 4–7 Hz
D. 0.5–4 Hz
Rationale: Beta waves are high-frequency rhythms seen during alert mental activity or anxiety.
11. What does a photic stimulation test during EEG evaluate?
☑ A. Photosensitive epilepsy
B. Sleep disorders
C. Stroke localization
D. Brain death
Rationale: Photic stimulation can trigger epileptiform discharges in patients with photosensitive
epilepsy.
12. Which EEG pattern is a hallmark of absence seizures?
☑ A. 3 Hz generalized spike-and-wave
B. Delta waves
C. Theta slowing
D. Beta bursts
Rationale: Typical absence seizures show symmetric, generalized 3 Hz spike-and-wave
discharges.
, 13. Which region is commonly monitored with sphenoidal electrodes?
☑ A. Temporal lobes
B. Occipital lobes
C. Frontal lobes
D. Central cortex
Rationale: Sphenoidal electrodes provide better detection of temporal lobe epileptiform activity.
14. Which artifact is characterized by high-frequency activity over temporal and
posterior electrodes during jaw movement?
☑ A. Muscle (EMG) artifact
B. Eye blink artifact
C. Electrode pop
D. 60 Hz electrical artifact
Rationale: Muscle activity produces high-frequency, low-amplitude spikes, often in temporal
regions.
15. What is the normal voltage range for adult awake EEG?
☑ A. 20–100 µV
B. 0.5–5 µV
C. 200–400 µV
D. 100–200 µV
Rationale: Adult awake EEG voltages typically range between 20–100 µV, varying with rhythm
and electrode location.
16. Which of the following is a normal variant seen in EEG?
☑ A. Lambda waves
B. Continuous spike-and-wave
C. Hypsarrhythmia
D. Triphasic waves
Rationale: Lambda waves are benign occipital transients seen during visual scanning.