ELECTROCORTICOGRAPHY AND
FUNCTIONAL MAPPING FOR CTLM BOARD
PREP VERIFIED 100% CORRECT
What is a clinical consequence of occluding the Vein of Galen?
a. Bilateral thalamic venous infarct
b. Brainstem venous infarct
c. None of the responses are correct
d. Left hemispheric venous infarct - Answer-a. Bilateral thalamic venous infarct
In functional cortical mapping a phase reversal occurs between the electrode contact
points located:
a. Between the L and R hemispheres
b. Between Broca's and Wernicke's areas
c. Between the central and temporal lobes
d. Between the Falx cerebri and the longitudinal fissure
e. Between the motor and sensory trip of the brain - Answer-e. Between the motor and
sensory trip of the brain
Awake craniotomy patients must have muscle relaxant on board to prevent their pulling
out the ET tube:
a. True
b. False - Answer-b. False (There is no ET tube used in awake surgeries)
The purpose of electrical stimulation of brainstem structures is to identify cranial motor
nuclei and their motor tracts.
a. True
b. False - Answer-a. True
Direct cortical stimulation of brain mapping can be done: (select all that apply)
-Intraoperatively
-Without need of surgery using surface scalp electrodes
-As an outpatient procedure
-Extra-operatively using implanted subdural electrodes - Answer--Extra-operatively
using implanted subdural electrodes
Which of the following is NOT a circulatory management strategy used during aortic
surgery?
a. Antegrade cerebral perfusion
b. Cardiopulmonary bypass
c. Retrograde cerebral perfusion
d. Hypothermia - Answer-d. Hypothermia
,It is imperative to have an understanding of the anatomy of the rhomboid fossa in order
to properly plan neurophysiological techniques to use for mapping.
True or False? - Answer-True
If we know normal brain anatomy and the the cytoarchitectural organization of the
Human Cerebral Cortex, why do we still need to do cortical stimulation during ECoG to
localize function
a. Right and left handed people have great variability in brain organization
b. Normal range variability and sometimes variations caused by abnormalities such as
tumors
c. Not enough studies have been done on normal brain function to establish normal
patterns - Answer-b. Normal range variability and sometimes variations caused by
abnormalities such as tumors
In mapping within the brainstem, there are special challenges in determining both a safe
approach and performing precise mapping. The use of monopolar and bipolar
stimulation can be useful but are thought to provide slightly different information. (Select
all statements that are true)
a. Bipolar stimulators are thought to be more sensitive
b. Monopolar stimulators are thought to be more sensitive, but more research is needed
c. Monopolar stimulators are thought to be more specific
d. Bipolar stimulators are thought to be more specific, but more research is needed -
Answer-b. Monopolar stimulators are thought to be more sensitive, but more research is
needed
d. Bipolar stimulators are thought to be more specific, but more research is needed
During speech mapping if the patient stops speaking, delays or has paraphasic errors
during stimulation, this is called a negative phenomenon and identification of speech is
then marked on the cortex with sterile pieces of paper.
True or False? - Answer-True
The functional data from stimulation of the cortex directly that results in an after-
discharge, is useful in mapping brain function.
True or False? - Answer-False
Occlusion of the innominate artery is most likely to cause:
a. Aphasia
b. Reduces pulses in the L arm
c. L hemispheric stroke
d. R hemispheric stroke - Answer-d. R hemispheric stroke
What is the recommended sampling rate for ECoG recordings?
a. 70 Hz is the minimum
b. 100 Hz is adequate
c. Nyquest frequency or twice the highest frequency recorded or 150Hz
, d. At least 250 Hz while 4-5 times the HFF is preferred - Answer-d. At least 250 Hz
while 4-5 times the HFF is preferred
Eloquent cortex refers to areas of the cerebral cortex that, if removed, could result in
significant neurological functional deficit.
True or False? - Answer-True
The solution for noise reduction in DBS is short shielded cables, placing the pre-Amp
near the recording electrode and making the capacitance between the shield and the
conductor virtually zero providing no path for noise between the shield and the
conductor.
True or False? - Answer-True
Broadmann's maps identify the general location in which we expect to find brain function
in most people.
True or False? - Answer-True
Testing of patients for motor, sensory, and or language function in ECoG with Cortical
Stimulation, is done using.
a. Trains of bipolar, constant current electrical stimulation applied to exposed cortex
during neurosurgery
b. Corkscrew surface electrodes applied to the scalp at CP3 and CP4
c. Monopolar, constant voltage, square wave single stimulations - Answer-a. Trains of
bipolar, constant current electrical stimulation applied to exposed cortex during
neurosurgery
Which of the factors below does NOT contribute substantially to the variability of the
SSEP during CABG surgery?
a. Changes in temperature
b. Changes in levels of halogenated inhalational agents
c. Use of narcotics
d. Fluctuations in blood pressure - Answer-c. Use of narcotics
Inclusion of IONM allows the neurosurgeon to perform tumor resection according to:
(select all that apply)
a. Achieve minimal risk of postoperative sequelae with preservation of quality of life
b. Functional boundaries thereby leading to the optimization of benefit/risk ratio in
surgical tumor removal
c. Extend surgery into eloquent brain areas
d. Achieve a better quality of tumor resection with better neuro-oncological impact -
Answer-a. Achieve minimal risk of postoperative sequelae with preservation of quality of
life
b. Functional boundaries thereby leading to the optimization of benefit/risk ratio in
surgical tumor removal
c. Extend surgery into eloquent brain areas
d. Achieve a better quality of tumor resection with better neuro-oncological impact
FUNCTIONAL MAPPING FOR CTLM BOARD
PREP VERIFIED 100% CORRECT
What is a clinical consequence of occluding the Vein of Galen?
a. Bilateral thalamic venous infarct
b. Brainstem venous infarct
c. None of the responses are correct
d. Left hemispheric venous infarct - Answer-a. Bilateral thalamic venous infarct
In functional cortical mapping a phase reversal occurs between the electrode contact
points located:
a. Between the L and R hemispheres
b. Between Broca's and Wernicke's areas
c. Between the central and temporal lobes
d. Between the Falx cerebri and the longitudinal fissure
e. Between the motor and sensory trip of the brain - Answer-e. Between the motor and
sensory trip of the brain
Awake craniotomy patients must have muscle relaxant on board to prevent their pulling
out the ET tube:
a. True
b. False - Answer-b. False (There is no ET tube used in awake surgeries)
The purpose of electrical stimulation of brainstem structures is to identify cranial motor
nuclei and their motor tracts.
a. True
b. False - Answer-a. True
Direct cortical stimulation of brain mapping can be done: (select all that apply)
-Intraoperatively
-Without need of surgery using surface scalp electrodes
-As an outpatient procedure
-Extra-operatively using implanted subdural electrodes - Answer--Extra-operatively
using implanted subdural electrodes
Which of the following is NOT a circulatory management strategy used during aortic
surgery?
a. Antegrade cerebral perfusion
b. Cardiopulmonary bypass
c. Retrograde cerebral perfusion
d. Hypothermia - Answer-d. Hypothermia
,It is imperative to have an understanding of the anatomy of the rhomboid fossa in order
to properly plan neurophysiological techniques to use for mapping.
True or False? - Answer-True
If we know normal brain anatomy and the the cytoarchitectural organization of the
Human Cerebral Cortex, why do we still need to do cortical stimulation during ECoG to
localize function
a. Right and left handed people have great variability in brain organization
b. Normal range variability and sometimes variations caused by abnormalities such as
tumors
c. Not enough studies have been done on normal brain function to establish normal
patterns - Answer-b. Normal range variability and sometimes variations caused by
abnormalities such as tumors
In mapping within the brainstem, there are special challenges in determining both a safe
approach and performing precise mapping. The use of monopolar and bipolar
stimulation can be useful but are thought to provide slightly different information. (Select
all statements that are true)
a. Bipolar stimulators are thought to be more sensitive
b. Monopolar stimulators are thought to be more sensitive, but more research is needed
c. Monopolar stimulators are thought to be more specific
d. Bipolar stimulators are thought to be more specific, but more research is needed -
Answer-b. Monopolar stimulators are thought to be more sensitive, but more research is
needed
d. Bipolar stimulators are thought to be more specific, but more research is needed
During speech mapping if the patient stops speaking, delays or has paraphasic errors
during stimulation, this is called a negative phenomenon and identification of speech is
then marked on the cortex with sterile pieces of paper.
True or False? - Answer-True
The functional data from stimulation of the cortex directly that results in an after-
discharge, is useful in mapping brain function.
True or False? - Answer-False
Occlusion of the innominate artery is most likely to cause:
a. Aphasia
b. Reduces pulses in the L arm
c. L hemispheric stroke
d. R hemispheric stroke - Answer-d. R hemispheric stroke
What is the recommended sampling rate for ECoG recordings?
a. 70 Hz is the minimum
b. 100 Hz is adequate
c. Nyquest frequency or twice the highest frequency recorded or 150Hz
, d. At least 250 Hz while 4-5 times the HFF is preferred - Answer-d. At least 250 Hz
while 4-5 times the HFF is preferred
Eloquent cortex refers to areas of the cerebral cortex that, if removed, could result in
significant neurological functional deficit.
True or False? - Answer-True
The solution for noise reduction in DBS is short shielded cables, placing the pre-Amp
near the recording electrode and making the capacitance between the shield and the
conductor virtually zero providing no path for noise between the shield and the
conductor.
True or False? - Answer-True
Broadmann's maps identify the general location in which we expect to find brain function
in most people.
True or False? - Answer-True
Testing of patients for motor, sensory, and or language function in ECoG with Cortical
Stimulation, is done using.
a. Trains of bipolar, constant current electrical stimulation applied to exposed cortex
during neurosurgery
b. Corkscrew surface electrodes applied to the scalp at CP3 and CP4
c. Monopolar, constant voltage, square wave single stimulations - Answer-a. Trains of
bipolar, constant current electrical stimulation applied to exposed cortex during
neurosurgery
Which of the factors below does NOT contribute substantially to the variability of the
SSEP during CABG surgery?
a. Changes in temperature
b. Changes in levels of halogenated inhalational agents
c. Use of narcotics
d. Fluctuations in blood pressure - Answer-c. Use of narcotics
Inclusion of IONM allows the neurosurgeon to perform tumor resection according to:
(select all that apply)
a. Achieve minimal risk of postoperative sequelae with preservation of quality of life
b. Functional boundaries thereby leading to the optimization of benefit/risk ratio in
surgical tumor removal
c. Extend surgery into eloquent brain areas
d. Achieve a better quality of tumor resection with better neuro-oncological impact -
Answer-a. Achieve minimal risk of postoperative sequelae with preservation of quality of
life
b. Functional boundaries thereby leading to the optimization of benefit/risk ratio in
surgical tumor removal
c. Extend surgery into eloquent brain areas
d. Achieve a better quality of tumor resection with better neuro-oncological impact
