ABRET CNIM REVIEW PAPER 2026
COMPLETE QUESTION SET ACCURATE
ANSWERS
◉ ECoG: advantage of grid/strip electrodes over "crown of thorns".
Answer: ability to slide them under dura to unexposed areas
◉ Once grids & strips are placed and a pt (evaluated for possible
epilepsy surgery) is sent back to the epilepsy monitoring unit:.
Answer: -Extra-op mapping (tests may be done for motor, sensory,
speech, language, memory; reports generated)
-Anti-epileptic meds may be discontinued
-Stimulus delivery, watch for AD's, annotate functional responses
◉ After Discharges (AD).
Answer: -repetitive electrographic bursts, slowing, and/or spike-
wave activity
-occur in response to electrical stimulation @ brain surface
◉ Problems w/ AD's.
Answer: -Thresholds (may be elevated in areas w/ structural
damage; may vary from place-to-place & time-to-time)
,-AD's may arise from places w/ no significant spontaneous seizure
activity
-AD's may lead to seizures that, if occur during mapping --> pt can't
continue w/ mapping
◉ When pt cooperation is lacking and mapping cannot be done w/
the pt awake:.
Answer: -Mapping can be done w/ pt asleep
-Surgical staff can watch the pt under the drapes for evidence of
motor responses (facial twitches, hand mvmnt)
◉ TCD transducer frequencies.
Answer: 2.0 MHz
◉ TCD: nml waveforms.
Answer: have a brisk upstroke
◉ TCD: primary quantitative value.
Answer: velocity
◉ TCD: micro-embolic signals.
Answer: have a short duration of < .1 s
,◉ sEMG: nerve root patterns.
Answer: -Irritation = soft, intermittent flutter (indicative of working
near nerve/nucleus)
-Injury = continuous, non-accelerating tapping (indicative of
permanent injury)
-Accelerated firing = pattern --> nerve injury
◉ What differentiates an sEMG train from a burst?.
Answer: synchronicity & repetitiveness
◉ sEMG trains.
Answer: -reflect sustained nerve traction or compression
-suggestive of some degree of neural insult
◉ sEMG response similar to burst; occurs in the "cross sword"
phenomena when metal touches metal:.
Answer: due to capacitive discharge from the metal
◉ Which mm's would be most appropriate to monitor sEMG for L5 &
S1 nerve roots?.
Answer: PL (L5-S1) & Semimembranosus (L5-S2)
◉ If a pedicle screw tests above the accepted threshold?.
, Answer: Inform surgeon of an acceptable screw value
◉ Trigeminal (CN V) sEMG muscles:.
Answer: Masseter or Temporalis
◉ Facial (CN VII) sEMG muscles:.
Answer: Frontalis, Obicularis Oculi/Oris, Mentalis
◉ Sensitive stimulator electrode during CN VII recording.
Answer: bipolar concentric EMG needle
◉ CN VII stimulation - advantage of bipolar over monopolar
stimulation.
Answer: greater specificity
◉ In monopolar CN VII stimulation, (+) charge flows from:.
Answer: anode --> cathode
◉ The integrity of CN VII in acoustic neuroma surgery is determined
by:.
Answer: proximal CMAPs
COMPLETE QUESTION SET ACCURATE
ANSWERS
◉ ECoG: advantage of grid/strip electrodes over "crown of thorns".
Answer: ability to slide them under dura to unexposed areas
◉ Once grids & strips are placed and a pt (evaluated for possible
epilepsy surgery) is sent back to the epilepsy monitoring unit:.
Answer: -Extra-op mapping (tests may be done for motor, sensory,
speech, language, memory; reports generated)
-Anti-epileptic meds may be discontinued
-Stimulus delivery, watch for AD's, annotate functional responses
◉ After Discharges (AD).
Answer: -repetitive electrographic bursts, slowing, and/or spike-
wave activity
-occur in response to electrical stimulation @ brain surface
◉ Problems w/ AD's.
Answer: -Thresholds (may be elevated in areas w/ structural
damage; may vary from place-to-place & time-to-time)
,-AD's may arise from places w/ no significant spontaneous seizure
activity
-AD's may lead to seizures that, if occur during mapping --> pt can't
continue w/ mapping
◉ When pt cooperation is lacking and mapping cannot be done w/
the pt awake:.
Answer: -Mapping can be done w/ pt asleep
-Surgical staff can watch the pt under the drapes for evidence of
motor responses (facial twitches, hand mvmnt)
◉ TCD transducer frequencies.
Answer: 2.0 MHz
◉ TCD: nml waveforms.
Answer: have a brisk upstroke
◉ TCD: primary quantitative value.
Answer: velocity
◉ TCD: micro-embolic signals.
Answer: have a short duration of < .1 s
,◉ sEMG: nerve root patterns.
Answer: -Irritation = soft, intermittent flutter (indicative of working
near nerve/nucleus)
-Injury = continuous, non-accelerating tapping (indicative of
permanent injury)
-Accelerated firing = pattern --> nerve injury
◉ What differentiates an sEMG train from a burst?.
Answer: synchronicity & repetitiveness
◉ sEMG trains.
Answer: -reflect sustained nerve traction or compression
-suggestive of some degree of neural insult
◉ sEMG response similar to burst; occurs in the "cross sword"
phenomena when metal touches metal:.
Answer: due to capacitive discharge from the metal
◉ Which mm's would be most appropriate to monitor sEMG for L5 &
S1 nerve roots?.
Answer: PL (L5-S1) & Semimembranosus (L5-S2)
◉ If a pedicle screw tests above the accepted threshold?.
, Answer: Inform surgeon of an acceptable screw value
◉ Trigeminal (CN V) sEMG muscles:.
Answer: Masseter or Temporalis
◉ Facial (CN VII) sEMG muscles:.
Answer: Frontalis, Obicularis Oculi/Oris, Mentalis
◉ Sensitive stimulator electrode during CN VII recording.
Answer: bipolar concentric EMG needle
◉ CN VII stimulation - advantage of bipolar over monopolar
stimulation.
Answer: greater specificity
◉ In monopolar CN VII stimulation, (+) charge flows from:.
Answer: anode --> cathode
◉ The integrity of CN VII in acoustic neuroma surgery is determined
by:.
Answer: proximal CMAPs
