CNIM Frequent Miss Exam 2023 with Complete Solutions

A patient with a body temperature of 30 degrees C will have: A- Decreased latencies B- Decreased latencies, decreased amplitudes C- Increased latencies D- Increased latencies, decreased amplitudes - ANSWER-C- Increased latencies The P31 response to posterior tibial nerve stimulation: A- Is recordable over a generalized region of scalp B- Is best recorded by an electrode placed at CS5 C- Is generated by the thalamus D- Reflects post-synaptic activity in the cervical spinal cord - ANSWER-A- Is recordable over a generalized region of scalp Why are SSEP and MEP used simultaneously? A- Because MEPs indicate spinothalamic tract function B- Spinal cord damage can occur in only one tract causing loss of MEP but not SSEP C- Because SSEP monitoring alone is not very sensitive to changes in spinal cord function D- All of the above - ANSWER-B- Spinal cord damage can occur in only one tract causing loss of MEP but not SSEP If the bin width of you system is 20 μS, then the highest frequency signal that can be resolved is: A- 50 KHz B- 100 KHz C- 25 KHz D- 20 KHz - ANSWER-C- 25 KHz EEG will most likely disappear at what body temperature? A- 16 º C B- 36º C C- 23 º C D- 28º C - ANSWER-A- 16 º C What will be the frequency of a signal if in a 30 mS sweep the interval between each cycle of the signal is 0.03 mS? A- 3333 KHz B- 33 KHz C- 333 KHz D- 3 KHz - ANSWER-B- 33 KHz According to the Guidelines what is the acceptable sweep for ABR's? A- 20-30 msec B- 10-15 msec C- 5 msec D- 25 msec - ANSWER-B- 10-15 msec You do not want to use a power extension cord because: A- It is a fire hazard B- It will mean that more current could be delivered to the patient if the ground fails C- It may interfere with the operation of other devices in the operating room D- It will increase your risk of ground leakage - ANSWER-D- It will increase your risk of ground leakage Which of the following is a barbiturate? A- Methohexital B- Remifentanyl C- Nitrous Oxide D- Curare - ANSWER-A- Methohexital Tinel's sign A- Cortex B- Spinal cord C- Muscle D- Peripheral nerve - ANSWER-D- Peripheral nerve Cortel-Dubousset instrumentation involves which of the following? A- Derotation B- Distraction C- Sublaminar wires D- Intervertebral diskectomy - ANSWER-A- Derotation A loss of SSEP response would most likely occur ________ to the surgical site. A- Anterior B- Caudal C- Posterior D- Rostral - ANSWER-D- Rostral What is the noise reduction technique that best reduces EKG artifact? A- Common mode rejection B- Averaging C- Artifact reject D- Hicut filter - ANSWER-C- Artifact reject When you have a salt bridge you will: A- Be able to stimulate the underlying nerve better B- Create a lethal pathway for current C- Max out your impedances D- Have difficulty stimulating the underlying nerve - ANSWER-D- Have difficulty stimulating the underlying nerve All of the following are benefits of EEG monitoring during carotid endarterectomy except: A- Selective shunting B- Detection of hypoxia C- Detection of occlusion-associated ischemia D- Detection of heparin dosage - ANSWER-D- Detection of heparin dosage If you have a 5 μV signal amplitude and a 20 μV noise amplitude, how many averages would you need to get a signal to noise ratio of 2:1? A- 100 B- 20 C- 64 D- 16 - ANSWER-C- 64 Which component would be most affected by a tumor by the intersection of the spinal cord and medulla? A- N13 B- P31 C- N20 D- EP - ANSWER-A- N13 What type of electrode is recommended for monitoring facial nerve? A- Cueva nerve electrode B- Ring electrode C- Surface D- Hook-wire - ANSWER-D- Hook-wire The stimulation rate is determined by the: A- Stimulus intensity B- Nerve conduction velocity C- Analysis time D- Number of stimulations - ANSWER-C- Analysis time What is the MAXIMUM time in which to expect EEG changes following cross clamping of the carotid? A- 30 seconds B- 5 minutes C- 2 minutes D- 1 minute - ANSWER-C- 2 minutes The most appropriate ABR interstimulus interval is: A- 20 mS B- 0.02 mS C- 50 mS D- 5 mS - ANSWER-A- 20 mS Which of the following is most affected by halogenated agents? A- Auditory brainstem response B- Posterior tibial cortical potential C- Median nerve subcortical response D- Lumbar response to PTN stimulation - ANSWER-B- Posterior tibial cortical potential The appropriate analysis time for ABRs is: A- 100 mS B- 50 mS C- 15 mS D- 20 mS - ANSWER-C- 15 mS During electrocautery we should: A- Pause recording B- Continue to average and watch raw traces C- Run impedances to let the amp desaturate D- Request the surgeon to stop - ANSWER-A- Pause recording Compound muscle action potentials to transcranial electric stimulation are susceptible to: A- Pavulon B- Isoflurane C- Propofol D- All of the above - ANSWER-D- All of the above Stimulating the median nerve at the wrist yields an Erb's point response at 10 mS and an NCV of 60 m/S. What is the distance between the cathode and the Erb's point recording electrode? A- Cannot be determined with this information B- 60 cm C- 50 cm D- 166 cm - ANSWER-B- 60 cm Excessive cerumen may cause: A- Increased I-V interpeak latencies B- Absence of wave V C- Absence of the BAER D- Increased I-III interpeak latencies - ANSWER-C- Absence of the BAER To protect the patient from inadvertent shock during power ‐ on and power ‐ off, the maximum leakage current through patient leads should be A- 10 milliamps B- 1 microamp C- 100 microamps D- 10 microamps - ANSWER-D- 10 microamps When the number of trial rejections increases during electrocautery, the best action is: A- Pause data collection B- Inform surgeon C- Increase number of sweeps D- Increase stimulus intensity - ANSWER-A- Pause data collection Cardiac activity appears on the CSA/DSA display as: A- beta activity B- alpha activity C- delta activity D- intermittent theta - ANSWER-C- delta activity In general, filter settings for SEP recordings A- can be narrower for cortical than peripheral responses B- should always be 30 ‐ 3000 Hz C- should always include 60 Hz band pass filters D- can be narrower for peripheral than cortical responses - ANSWER-A- can be narrower for cortical than peripheral responses Transcranial Magnetic Evoked Potentials are preferred over Transcranial Electric motor evoked potentials for intraoperative monitoring because: A- They are not preferred for intraoperative monitoring B- They require less rigorous anesthetic management C- They are painless D- There is no risk of seizures - ANSWER-A- They are not preferred for intraoperative monitoring The agent least depressing SEP monitoring is probably A- pancuronium B- vecuronium C- ketamine D- sevoflurane - ANSWER-C- ketamine What is the main advantage of asynchronous bilateral stimulation? A- Less patient movement B- Reduction of stimulus artifact C- Faster data acquisition D- Differentiation of local vs. systemic effects - ANSWER-D- Differentiation of local vs. systemic effects Movement artifact on the EEG is most likely to produce A- slow EEG wave activity B- fast EEG wave activity C- asymmetrical activity at 60 Hz D- burst‐suppression - ANSWER-A- slow EEG wave activity Which of the following could cause a false negative in a T10 surgery? A- Synchronous PTN stimulation B- Asynchronous PTN stimulation C- Asynchronous peroneal stimulation