CNIM Exam 2023 Questions and Answers

During electrocautery you should... - ANSWER-Pause Recording SSEPs are less reliable in patients with... - ANSWER-Neuromuscular disease After-discharges occur after what? - ANSWER-Direct cortical stimulation In order to reduce stimulus artifact, the ground electrode shoudl be placed... - ANSWER-On the limb between the stimulating and recording electrodes Which of the following is the most effected by halogenated agents? - ANSWER-Posterior Tibial cortical potential The nerve roott entry levels for the ulnar nerve are.. - ANSWER-C8-T1 When doing a C5 decompression involving the axillary nerve which muscle should you record from? - ANSWER-Deltoid Train stimuli are used for TcMEP's in order to... - ANSWER-Overcome anesthetic suppression of synaptic transmissions in the motor pathway What is the preferred alternate when the PTN is unavailable? - ANSWER-Peroneal Nyquist Frequency - ANSWER-One half the frequency of the recorded signal A decrease in the power spectral edge indicates.. - ANSWER-a greater proportion of EEG power at the lower frequencies Why do we use electrodes with the same metals? - ANSWER-To prevent electrode polarization Which of the following drugs has an appreciable effect on peripheral nerve APs - ANSWER-none Which one of the following is an inhibitory neurotransmitter - ANSWER-GABA Stimulating the median nerve at the wrist yields an Erbs point response at 10ms and an CV of 60m/s. What is the distance between the cathode and the Erb's point recording electrode - ANSWER-60cm What are SSEP and MEP used simultaneously? - ANSWER-Spinal cord damage can occur in only one tract causing loss of MEp but not SSEP Common Mode Rejection - ANSWER-Is the cancellation of signals that are common to both inputs of the ampifier Ankylosis - ANSWER-Fused Joint Where is the ABR wave V generated? - ANSWER-Mdbrain If you cannot replace an electrode that has come out during surgery you? - ANSWER-use a duplicate A patient with the temperature of 30 debrees C will have - ANSWER-increased latencies Which would not be considered contamination of the sterile field - ANSWER-reaching underneath the surgeon's gown to grab his pager Personal Protection Devices (PPDs) consist of - ANSWER-gloves, masks, gowns When an electrode fall on the floor you - ANSWER-you immediately pick it up to dispose of it in a sharps container when testing BAEP's you get a wave I on your contralateral ear montage. What do you do? - ANSWER-Check ear phones for porper side stimulation When no phase reversal is present in an anterior-posterior cortical grid recording - ANSWER-The maximum amplitude response is closest to the central sulcus The Artery of Admkiewicz is - ANSWER-a major feeder vessel to the spinal cord Which of the following is a barbiturate? - ANSWER-Methohexital Which electrode is regarded as an effective stimulator during facial nerve recordings? - ANSWER-Bipolar concentric EMG needle The primary risk associated with sublaminar wire placement is - ANSWER-Dorsal column injury One of the risks of a wake up test is? - ANSWER-Accidental extubation A 60Hz artifact would most likely be caused by: - ANSWER-Infusion Pump Your initial signal is 0.5microV inside a background noise of 2microV. What will the signal to noise ratio be after 400 averages? - ANSWER-5 What is not an advantage of epidural recording? - ANSWER-absence of significant artifact When securing PTN stimulators you want to make sure - ANSWER-the anode is distal to the cathode which of thefolowing is most consistent with a discrete lesion of the medial geniculate body? - ANSWER-No changes in waves I-V you record a spinal potential to - ANSWER-establish an AP the facial nerve CMAP response has a latency approximately - ANSWER-7ms tto establish crossover, the guidelines suggest a masking level of - ANSWER-60dB pe SPL Impedance is - ANSWER-opposition to alternating current flow The tibial and common peroneal nerves form what nerve? - ANSWER-Sciatic when placing PTN stimulator you should not - ANSWER-secure the tape and bands around the whole ankle cranial nerve IV can be monitored using electrodes inserted into the - ANSWER-superior oblique what will be the frequency of a signal if in a 30ms sweep the interval between each cycle of the signal is 0.03ms - ANSWER-33KHz What other type pf monitoring should be done during a microvascular decompreession of the trigeminal nerve along with BAER - ANSWER-VIIth cranial nerve EMG How should needle electrodes be discaraded - ANSWER-only in a red puncture-proof sharps container During an anterior lumbar (L4-L5), a loss of all right PTN repsonses occurs over the course of about 5 mintutes. What should you do? - ANSWER-Check the current output and stimulator connections quicckly. Then inform the surgeon you are seeing changes consistent with ischemia of the right leg Upper extremity SEPs transmit through which spinal cord tract - ANSWER-Fasciculus Epileptiform discharges can localized by - ANSWER-A Mu rythym Which of the following could be used to monitor facial nerve EMG - ANSWER-Mentalis Which of the following is consistent with increasing depth of anesthesia - ANSWER-Bilateral reduction of cortical SEPs only what is a possible reason for the change in wave V - ANSWER-retraction of cerebellum the trigeminal nerve EMG response has a latency of approximately.. - ANSWER-3-5ms Which time constanct would be most effective for cutting out low frequency noise from your signal? - ANSWER-10ms What is the benefit of using epidural electrodes? - ANSWER-They are highly sensitive Kyphosis - ANSWER-Curvature of the thoracic spine During a posterior fossa resection of acoustic neuroma surgery, you observe the loss of wave II of the BAER. What should you do? - ANSWER-Continue to monitor without alarm Cortel-Dubousset instrumentation involves which of the following? - ANSWER-Derotation When testin BAEP's you get a wave on your contralateral ear montage. What do you do? - ANSWER-check ear phones for proper ear stimulation the input impedance of a differential amplifier should be - ANSWER-at least 100MOhms You want your vertical resolution to - ANSWER-match the amplitude of your input to maximize the signal When testing SSEP from the upper extremity, a electrde placed at Erb's point will record activity generated from - ANSWER-Brachial plexus When no phase reversal is present in an anterior-pposteerior cortical grid recording - ANSWER-The maximum amplitude response is closest to the central sulcus Having poor ground resistance represents a safety problem becauses - ANSWER-any current leaking to the chassis may find a pathy to ground through your body The P31 response to posterior tibial nerve stimulation - ANSWER-is recordable over generalized region of scalp During median nerve preoperative study, a patient has discomfort at the wrist. Which of the following would most likely reduce the patient's discomfort while maintaining adequate stimulation? - ANSWER-Decrease number of repetitions Random spike discharges can be heard from a speaker during facial nerve dissection in all of the following except - ANSWER-During electrocautery What determines the latency of SSEPs most? - ANSWER-Limb length 1-204 Platinum electrodes are used to record epidural potentials because - ANSWER-Other elements cause neurotoxicity when current is passed through them A typical resting membrane potential of a neuron is - ANSWER--70mV inside the cell EEG will most likely disappear at what body temp? - ANSWER-16C Activation of an action potential of a neuron will depend on - ANSWER-Its membrane potential based on the spatiotemporal summation fo its excititoty and inhibitory inputs What cranial nerves should be ideally monitored for Cerebelloponitine (CP) angle tumor? - ANSWER-VII and VIII