EEG MASTERY LAB · OFFLINE POWERPOINT
Question Bank 11
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 301
A scalp EEG is normal while a subdural grid shows a focal interictal
spike confined to a few contacts. What should the EEG report imply?
A. There is no cortical irritability
B. The intracranial spike may be real but too restricted to produce a scalp field
C. The scalp electrodes must be disconnected
D. The finding proves generalized epilepsy
EEG MASTERY · BANK 11 · QUESTION 1/30
,ANSWER 1 · SOURCE 301
A scalp EEG is normal while a subdural grid shows a focal interictal spike
confined to a few contacts. What should the EEG report imply?
B. The intracranial spike may be real but too restricted to produce a scalp field
CLINICAL RATIONALE
A. Not correct. Scalp negativity does not exclude local intracranial irritability. B. Correct. A spike confined to a small cortical region may
not overcome tissue attenuation or background activity enough to be visible on scalp EEG. C. Not correct. Disconnected electrodes
are possible but should be suspected from technical features, not simply from absence of scalp correlate. D. Not correct. A focal
intracranial spike does not prove generalized epilepsy.
EEG MASTERY · BANK 11 · ANSWER 1/30
, QUESTION 2 · Medium · SOURCE 302
Which phrase best describes the type of cortical activation most
likely to generate a scalp spike?
A. Random asynchronous activity in scattered small patches
B. Single-neuron action potentials in deep cortex
C. Synchronous or temporally overlapping activation of a sufficiently large gyral cortical area
D. Pure scalp muscle contraction without cerebral field
EEG MASTERY · BANK 11 · QUESTION 2/30
Question Bank 11
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 301
A scalp EEG is normal while a subdural grid shows a focal interictal
spike confined to a few contacts. What should the EEG report imply?
A. There is no cortical irritability
B. The intracranial spike may be real but too restricted to produce a scalp field
C. The scalp electrodes must be disconnected
D. The finding proves generalized epilepsy
EEG MASTERY · BANK 11 · QUESTION 1/30
,ANSWER 1 · SOURCE 301
A scalp EEG is normal while a subdural grid shows a focal interictal spike
confined to a few contacts. What should the EEG report imply?
B. The intracranial spike may be real but too restricted to produce a scalp field
CLINICAL RATIONALE
A. Not correct. Scalp negativity does not exclude local intracranial irritability. B. Correct. A spike confined to a small cortical region may
not overcome tissue attenuation or background activity enough to be visible on scalp EEG. C. Not correct. Disconnected electrodes
are possible but should be suspected from technical features, not simply from absence of scalp correlate. D. Not correct. A focal
intracranial spike does not prove generalized epilepsy.
EEG MASTERY · BANK 11 · ANSWER 1/30
, QUESTION 2 · Medium · SOURCE 302
Which phrase best describes the type of cortical activation most
likely to generate a scalp spike?
A. Random asynchronous activity in scattered small patches
B. Single-neuron action potentials in deep cortex
C. Synchronous or temporally overlapping activation of a sufficiently large gyral cortical area
D. Pure scalp muscle contraction without cerebral field
EEG MASTERY · BANK 11 · QUESTION 2/30
