ECOG/EP for CLTM question n answers graded A+ 2023/2024

ECOG/EP for CLTMnearfield, post-synaptic activity in cervical spinal cord - correct answer N13 far-field, caudal medial/lemniscus (AEP) - correct answer P14 far-field, post-synaptic activity from several sites in the brain stem and thalamus - correct answer N18 near-field, somatosensory cortex potential - correct answer N20 median generator sites - correct answer N13 P14 N18 N20 electrode impedance with ECOG - correct answer higher- placement is unstable reference electrode in ecog - correct answer placed away from active electrodes in the subgleal space LFF in ecog - correct answer can be raised to 5-10 Hz primary interest is spikes- not slow waves responses required in cortical SSEP ecog - correct answer response is much larger than scalp-recorded less than 100 average responses are needed OR troubleshooting - correct answer -ask surgeon to stop electrocautery temporarily to document the artiface -60 Hz notch is prohibited -primary non-electrical issue is effect of anesthesia -other issues include vital signs and positioning positioning during ecog - correct answer avoid hyperextension of joints can be adjusted slightly to reduce discomfort during craniotomy (stiffness) true or false: longer latency potentials are more sensitive to anesthesia - correct answer true which are less affected by anesthesia in ecog: P26, N30, P40, N60 OR P14 and N20 (subcortical and 1st cortical potentials) - correct answer P14 and N20 subcortical and 1st cortical potentials effect of halogenated inhalation agents in ecog/ep - correct answer attenuate or abolish EP and prolong latencies true or false: TCMEPs are much more sensitive than SSEP - correct answer true commonly used inhalation anesthetics - correct answer nitrous oxide (N2O) halothane desflurane isoflurane MAC - correct answer -Minimal Alveolar Concentration (of inhaled anesthetic) required to prevent 50% of subjects from moving in response to noxious stimulus short latency response - correct answer -brainstem components, far field potentials -more resistant to anesthesia than long-latency responses (cortical) P14 - correct answer Cuneate nucleus(medulla), Far field