EEG MASTERY LAB · OFFLINE POWERPOINT
Question Bank 10
30 questions · matched answer slides · clinical rationales
Advance one slide to reveal each answer. Full source rationales are preserved in the
answer-slide notes.
,QUESTION 1 · Medium · SOURCE 271
In simultaneous scalp and intracranial EEG, intracranial electrodes show
many more spikes than the scalp recording. What is the most appropriate
conclusion?
A. Intracranial EEG is more sensitive to small and local cortical events than scalp EEG
B. Scalp EEG is technically invalid whenever it misses an intracranial spike
C. All intracranial spikes have the same localizing value as scalp-visible spikes
D. The patient must have multifocal epilepsy whenever many intracranial spikes are present
EEG MASTERY · BANK 10 · QUESTION 1/30
,ANSWER 1 · SOURCE 271
In simultaneous scalp and intracranial EEG, intracranial electrodes show many
more spikes than the scalp recording. What is the most appropriate conclusion?
A. Intracranial EEG is more sensitive to small and local cortical events than scalp EEG
CLINICAL RATIONALE
A. Correct. Intracranial electrodes are close to the cortex and detect local events that may be too small, deep, or poorly oriented to
appear on scalp EEG. B. Not correct. Scalp EEG is expected to miss many local intracranial events. This is a physiologic limitation,
not a technical invalidation. C. Not correct. Local intracranial spikes may be numerous and variable. Scalp-visible spikes may
represent a selected subpopulation with broader recruitment. D. Not correct. Multiple intracranial spikes do not automatically establish
multifocal epilepsy. They must be interpreted in the full presurgical context.
EEG MASTERY · BANK 10 · ANSWER 1/30
, QUESTION 2 · Medium · SOURCE 272
A source-localization display shows a scalp temporal spike arising from a
tiny 1 cm2 cortical patch. The spike is large and reproducible on scalp
EEG. What is the main concern?
A. The scalp spike must be generalized and cannot be temporal
B. The patient must have a skull defect causing all EEG to be invalid
C. The source model should always ignore cortical anatomy
D. The modeled source is probably unrealistically small for a visually prominent scalp spike
EEG MASTERY · BANK 10 · QUESTION 2/30
Question Bank 10
30 questions · matched answer slides · clinical rationales
Advance one slide to reveal each answer. Full source rationales are preserved in the
answer-slide notes.
,QUESTION 1 · Medium · SOURCE 271
In simultaneous scalp and intracranial EEG, intracranial electrodes show
many more spikes than the scalp recording. What is the most appropriate
conclusion?
A. Intracranial EEG is more sensitive to small and local cortical events than scalp EEG
B. Scalp EEG is technically invalid whenever it misses an intracranial spike
C. All intracranial spikes have the same localizing value as scalp-visible spikes
D. The patient must have multifocal epilepsy whenever many intracranial spikes are present
EEG MASTERY · BANK 10 · QUESTION 1/30
,ANSWER 1 · SOURCE 271
In simultaneous scalp and intracranial EEG, intracranial electrodes show many
more spikes than the scalp recording. What is the most appropriate conclusion?
A. Intracranial EEG is more sensitive to small and local cortical events than scalp EEG
CLINICAL RATIONALE
A. Correct. Intracranial electrodes are close to the cortex and detect local events that may be too small, deep, or poorly oriented to
appear on scalp EEG. B. Not correct. Scalp EEG is expected to miss many local intracranial events. This is a physiologic limitation,
not a technical invalidation. C. Not correct. Local intracranial spikes may be numerous and variable. Scalp-visible spikes may
represent a selected subpopulation with broader recruitment. D. Not correct. Multiple intracranial spikes do not automatically establish
multifocal epilepsy. They must be interpreted in the full presurgical context.
EEG MASTERY · BANK 10 · ANSWER 1/30
, QUESTION 2 · Medium · SOURCE 272
A source-localization display shows a scalp temporal spike arising from a
tiny 1 cm2 cortical patch. The spike is large and reproducible on scalp
EEG. What is the main concern?
A. The scalp spike must be generalized and cannot be temporal
B. The patient must have a skull defect causing all EEG to be invalid
C. The source model should always ignore cortical anatomy
D. The modeled source is probably unrealistically small for a visually prominent scalp spike
EEG MASTERY · BANK 10 · QUESTION 2/30
