1.
Which nerve should be stimulated for lower limb SSEP as recommended by ACNS guidelines for short-latency SSEP?
Correct Answer
A. Posterior tibial nerve
Explanation
The ACNS guidelines recommend stimulating the posterior tibial nerve for lower limb SSEP. This nerve is responsible for sensory innervation of the sole of the foot and its stimulation can provide accurate and reliable signals for assessing the function of the lower limb. Stimulation of the peroneal nerve, sciatic nerve, or median nerve would not be appropriate for lower limb SSEP as they do not specifically target the sensory innervation of the lower limb.
2.
Which nerve should be stimulated for upper limb SSEP as recommended by ACNS guidelines for short latency SSEP?
Correct Answer
A. Median nerve
Explanation
According to the ACNS guidelines for short latency SSEP, the recommended nerve to stimulate for upper limb SSEP is the median nerve.
3.
The active electrode is usually placed on the scalp 2cm behind _____ for lower limb SSEP.
Correct Answer
A. Vertex (Cz)
Explanation
The active electrode is usually placed on the scalp 2cm behind the vertex (Cz) for lower limb SSEP. The vertex (Cz) is a specific location on the scalp that is commonly used as a reference point in electroencephalography (EEG) studies. Placing the electrode 2cm behind the vertex ensures accurate recording of the lower limb somatosensory evoked potentials (SSEP) by capturing the electrical activity from the relevant neural pathways. The other options, Fpz, C3', and C4', are not the recommended placement sites for lower limb SSEP.
4.
The warning criteria for SSEP changes have been generally accepted as:
Which one do you like?
Correct Answer
A. 50% decrease in amplitude and/or 10% increase in latency
Explanation
The correct answer is 50% decrease in amplitude and/or 10% increase in latency. This means that if there is a 50% decrease in the amplitude of the SSEP signal or a 10% increase in the latency (delay) of the signal, it is considered a warning criteria for SSEP changes. These changes may indicate a potential problem or abnormality in the sensory evoked potentials.
5.
Electrode placement on the scalp for SSEP is based on:Which one do you like?
Correct Answer
A. 10-20 system
Explanation
The correct answer is the 10-20 system. The 10-20 system is a standardized method for placing electrodes on the scalp for measuring somatosensory evoked potentials (SSEP). It is based on the measurement of the distance between specific landmarks on the head, such as the nasion (the midpoint between the forehead and the bridge of the nose) and the inion (the bump at the back of the head). This system ensures consistent and accurate electrode placement across different individuals, allowing for reliable measurement and comparison of SSEPs.
6.
Central Conduction Time (CCT) for median nerve is calculated between which peaks?
Correct Answer
A. P14-N20
Explanation
The Central Conduction Time (CCT) for the median nerve is calculated between the peaks P14 and N20. These peaks represent the electrical activity in the brain that occurs when the median nerve is stimulated. By measuring the time between these two peaks, we can determine the speed at which the nerve conduction occurs.
7.
Peripheral Conduction Time (PCT) for median nerve is calculated between which peaks?
Correct Answer
A. EP-P14
Explanation
The correct answer is EP-P14. Peripheral Conduction Time (PCT) for the median nerve is calculated between the peaks EP (early potential) and P14. These peaks represent the electrical activity generated along the nerve pathway. By measuring the time between these peaks, the conduction time of the nerve can be determined. The other options, P14-N20, N13-N20, and EP-N20, do not accurately represent the peaks used to calculate PCT for the median nerve.
8.
Central Conduction Time for posterior tibial nerve is calculated between which peaks?
Correct Answer
A. LP-P37
Explanation
The central conduction time for the posterior tibial nerve is calculated between the peaks labeled LP and P37.
9.
Peripheral Conduction Time (PCT) for posterior tibial nerve is calculated between which peaks?
Correct Answer
A. PF-LP
Explanation
The correct answer is PF-LP. Peripheral Conduction Time (PCT) for the posterior tibial nerve is calculated between the peaks labeled PF and LP.
10.
SSEP is not recordable when cerebral perfusion drops below:
Correct Answer
A. 15 cc/min / 100 grams of tissue
Explanation
SSEP stands for somatosensory evoked potentials, which are electrical signals generated by the nervous system in response to sensory stimulation. These signals can be recorded and used to assess the integrity of the sensory pathways in the brain. The given answer states that SSEP is not recordable when cerebral perfusion drops below 15 cc/min / 100 grams of tissue. This means that if blood flow to the brain decreases below this threshold, the brain tissue may not receive enough oxygen and nutrients to function properly, leading to the inability to generate SSEP signals.
11.
The normal amplitude of SSEP responses recorded from scalp is approximately:
Correct Answer
A. 0.1uV to 10uV
Explanation
The normal amplitude of SSEP responses recorded from the scalp is approximately 0.1uV to 10uV. This range indicates the typical strength of the signals obtained during SSEP testing. SSEP responses are small electrical potentials generated by the nervous system in response to sensory stimulation. The amplitudes of these responses can vary depending on factors such as the type of stimulation, the location of the recording electrodes, and individual variability. However, a range of 0.1uV to 10uV is generally considered normal for SSEP recordings from the scalp.
12.
If there is a sudden loss in ipsilateral ERB’s point and contralateral N20 response, what is the first step for troubleshooting?
Correct Answer
A. Check arm positioning
Explanation
The sudden loss in ipsilateral ERB's point and contralateral N20 response suggests a potential issue with the arm positioning. It is important to check if the patient's arm is properly positioned, as improper positioning can lead to nerve compression or stretching, resulting in a loss of response. By checking the arm positioning, any issues can be identified and corrected, potentially restoring the response.
13.
Latency and/or amplitude changes in SSEP responses can result from:
Correct Answer
D. All of the above
Explanation
Latency and/or amplitude changes in SSEP responses can result from anesthesia/hypothermia, technical failure, and surgical manipulation. Anesthesia and hypothermia can affect the conduction of nerve signals and cause delays or alterations in the SSEP responses. Technical failure, such as electrode malfunction or improper signal amplification, can also lead to changes in SSEP measurements. Additionally, surgical manipulation can cause physical disruption or compression of the nerves, leading to changes in SSEP responses. Therefore, all of the mentioned factors can contribute to latency and/or amplitude changes in SSEP responses.
14.
The N20 responses is generated from which structure?
Correct Answer
A. The sensory cortex (contralateral to the stimulation side)
Explanation
The N20 responses are generated from the sensory cortex contralateral to the stimulation side. This means that when a stimulus is applied to one side of the body, the sensory information is processed in the sensory cortex on the opposite side of the brain.
15.
The P14 is generated from which structure?
Correct Answer
A. Caudal medial lemniscus
Explanation
The P14 is generated from the caudal medial lemniscus.
16.
The N34 subcortical response is a near field or far field response?
Correct Answer
B. Far field
Explanation
The N34 subcortical response is categorized as a far field response. Far field responses refer to electrical activity that originates from a distant source and can be recorded at a separate location. In the case of the N34 subcortical response, it is an electrical signal that is generated in the brain and can be measured at a location away from the source. This categorization helps in understanding the nature and characteristics of the response in terms of its generation and recording.
17.
Lumbar Potential (LP) is a stationary (non-propagated) potential.
Correct Answer
A. True
Explanation
Lumbar Potential (LP) is a stationary potential, meaning it does not propagate or move from one place to another. This suggests that LP remains localized in the lumbar region and does not spread throughout the body. Therefore, the statement "Lumbar Potential (LP) is a stationary (non-propagated) potential" is true.
18.
The most reliable criteria for SSEP abnormality is:
Correct Answer
C. Both
Explanation
The most reliable criteria for SSEP abnormality is the presence of both absence of the obligate waveforms and prolongation of the inter-peak latencies. This means that if either of these criteria is present, it indicates an abnormality in the SSEP.
19.
The N18 subcortical response is a near field or far field response?
Correct Answer
A. Far field
Explanation
The N18 subcortical response is classified as a far field response. Far field responses refer to electrical activity generated by neural structures that are located at a distance from the recording electrodes. In the case of the N18 response, it is generated by subcortical structures such as the brainstem. This distinction is important because far field responses are less affected by artifacts and noise compared to near field responses, which originate from neural structures closer to the recording electrodes.
20.
After stimulation of the median nerve at the wrist, the response recorded at the ERB’s point consists of:
Correct Answer
C. Both
Explanation
After stimulation of the median nerve at the wrist, the response recorded at the ERB's point consists of both an orthodromic sensory potential and an antidromic motor action potential. This means that there is a sensory response and a motor response recorded at the ERB's point. The orthodromic sensory potential indicates the transmission of sensory signals in the normal direction along the nerve, while the antidromic motor action potential indicates the transmission of motor signals in the opposite direction along the nerve.
21.
Obligatory waves of the posterior tibial nerve (PTN) are:
Correct Answer
A. PF, LP, P31, N34, & P37
22.
Obligatory waves of the median nerve (MN) are:
Correct Answer
A. N9, N13, P14, N18, & N20
Explanation
In nerve conduction studies, the obligatory waves of the median nerve (MN) serve as crucial indicators of nerve function and health. These waves include N9, N13, P14, N18, and N20, each representing specific electrical responses at distinct time intervals after nerve stimulation. By measuring the latencies and amplitudes of these waves, healthcare professionals can diagnose and assess nerve-related conditions, making these studies essential in the evaluation of conditions like carpal tunnel syndrome and various neuropathies.
23.
What is the location of injury if there is loss of subcortical and cortical SSEP responses but intact ERB’s point response?
Correct Answer
A. Brainstem / Thalamus
Explanation
Loss of subcortical and cortical SSEP responses but intact ERB's point response suggests an injury in the brainstem or thalamus. SSEP responses originate from the sensory pathways in the brain, including the subcortical and cortical regions. If these responses are lost, it indicates a disruption in these areas. On the other hand, ERB's point response is a test for the integrity of the brachial plexus, which is a network of nerves in the shoulder and arm. If this response is intact, it suggests that the injury is not in the brachial plexus. Therefore, the most likely location of the injury is in the brainstem or thalamus.
24.
Which of the following sensations are not transferred via dorsal column?
Correct Answer
C. Temperature
Explanation
Temperature sensation is not transferred via the dorsal column. The dorsal column is responsible for transmitting sensations such as proprioception (awareness of body position) and stereognosis (perception of shape and texture). Temperature sensation is transmitted through a different pathway called the spinothalamic tract.
25.
What is the blood supply of cortical responses elicited by median nerve stimulation?
Correct Answer
A. MCA: Middle cerebral artery
Explanation
The correct answer is MCA: Middle cerebral artery. The blood supply of cortical responses elicited by median nerve stimulation is provided by the middle cerebral artery. This artery supplies blood to the lateral surface of the cerebral hemisphere, including the primary motor and sensory cortices. Stimulation of the median nerve leads to the activation of these cortical areas, and the blood supply from the middle cerebral artery ensures the delivery of oxygen and nutrients to support this neural activity.
26.
Ohm’s law is mathematically expressed as:
Correct Answer
A. V=IR
Explanation
Ohm's law states that the voltage across a conductor is directly proportional to the current flowing through it, with the constant of proportionality being the resistance of the conductor. This can be mathematically expressed as V=IR, where V is the voltage, I is the current, and R is the resistance. This equation shows that the voltage is equal to the product of the current and the resistance.
27.
Good insulating materials that inhibit the current flow are:
Correct Answer
D. All of the above
Explanation
Good insulating materials are those that prevent or inhibit the flow of electric current. Glass, rubber, and wood are all examples of materials that have high resistance and therefore act as insulators. These materials do not easily allow the movement of electrons, making them suitable for applications where electrical conductivity needs to be avoided. Therefore, the correct answer is "All of the above" as all three materials listed are good insulators.
28.
What is the maximum allowable chassis leakage current?
Correct Answer
A. Less than 300uA RMS with ground open
Explanation
The maximum allowable chassis leakage current is less than 300uA RMS with ground open. This means that the amount of current that can leak from the chassis of the device to the ground when it is open should be less than 300uA RMS. This is an important specification to ensure the safety and proper functioning of the device.
29.
What is the maximum allowable leakage current through patient leads with 120AC applied?
Correct Answer
A. 10ums
Explanation
The maximum allowable leakage current through patient leads with 120AC applied is 10ums. This means that any leakage current exceeding 10ums would not be considered safe or within the acceptable range.
30.
In order to minimize filter-induced phase shift, the ratio of high to low frequency filter should be at least?
Correct Answer
A. 100:1
Explanation
To minimize filter-induced phase shift, the ratio of high to low frequency filter should be at least 100:1. This means that the cutoff frequency for the high-pass filter should be 100 times higher than the cutoff frequency for the low-pass filter. By having a higher ratio, the filter can effectively attenuate frequencies below the desired range and reduce phase shift, resulting in a more accurate and precise signal transmission.
31.
A large current passing form an external surface to another is known as:
Correct Answer
A. Macroshock
32.
A very low current as small as 10mV that can be lethal to the patient if it passes through the heart is known as:
Correct Answer
A. Microshock
Explanation
A very low current as small as 10mV that can be lethal to the patient if it passes through the heart is known as microshock. This term is used to describe an electrical shock that occurs within the body, specifically affecting the heart. The small current may not be felt by the patient, but it can disrupt the normal electrical signals in the heart, potentially leading to cardiac arrest or other serious complications. Therefore, it is important to be aware of the potential dangers of microshock and take appropriate precautions to prevent it.
33.
A band-stop filter is also called:
Correct Answer
A. 60Hz notch filter
Explanation
A band-stop filter is a type of electronic filter that allows frequencies within a certain range to pass through while attenuating or blocking frequencies outside of that range. In this case, a 60Hz notch filter specifically targets and filters out the 60Hz frequency, allowing other frequencies to pass through. This type of filter is commonly used to eliminate or reduce unwanted electrical interference or noise caused by power lines or other sources operating at 60Hz.
34.
What is the electrical line frequency in the operating rooms in the USA?
Correct Answer
A. 60Hz
Explanation
The electrical line frequency in operating rooms in the USA is 60Hz. This frequency is the standard for electrical power systems in North America, including the United States. It refers to the number of cycles per second that alternating current (AC) electricity completes in a power system. The 60Hz frequency ensures the proper functioning of electrical equipment and devices used in operating rooms, providing a stable and reliable power supply.
35.
The inter stimulus interval (ISI) of a 40Hz stimulation will be:
Correct Answer
A. 25ms
Explanation
The inter stimulus interval (ISI) refers to the time between consecutive stimuli in a stimulation sequence. In this case, the question states that the stimulation frequency is 40Hz. To calculate the ISI, we can use the formula: ISI = 1/frequency. Plugging in the given frequency of 40Hz, we get ISI = 1/40 = 0.025 seconds, which is equivalent to 25 milliseconds (ms). Therefore, the correct answer is 25ms.
36.
Unequal electrode impedances may result in:
Correct Answer
A. Increased noise
Explanation
Unequal electrode impedances can result in increased noise because when the impedances of the electrodes are not balanced, it can lead to uneven electrical signals being picked up by the electrodes. This can introduce interference and noise into the signal being measured or recorded. The unequal impedances can cause variations in the voltage levels, resulting in a distorted and noisy signal. Therefore, it is important to have balanced electrode impedances to minimize noise and ensure accurate measurements.
37.
The electrical charge stored by a capacitor is known as:
Correct Answer
A. Capacitance
Explanation
The electrical charge stored by a capacitor is known as capacitance. Capacitance is a measure of how much charge a capacitor can store per unit voltage. It is determined by the physical characteristics of the capacitor, such as the size of the plates and the distance between them. Impedance, inductance, and amperage are not related to the electrical charge stored by a capacitor.
38.
Opposition to change in current flow is known as:
Correct Answer
A. Inductance
Explanation
Inductance refers to the opposition or resistance to a change in current flow in a circuit. It is caused by the presence of an inductor, which stores energy in the form of a magnetic field. When the current flowing through the inductor changes, the magnetic field also changes, creating a counter electromotive force that opposes the change in current. Therefore, inductance can be considered as the opposition to change in current flow.
39.
Subdural electrodes made of platinum have what advantage?
Correct Answer
A. Stability during stimulation & MRI compatible
Explanation
Platinum subdural electrodes have the advantage of stability during stimulation and being MRI compatible. This means that they can withstand the electrical stimulation process without getting damaged and can also be used safely during MRI scans. This is beneficial as it allows for accurate and reliable data collection during stimulation and imaging procedures.
40.
The impedances of subdermal needle electrodes are typically higher than scalp electrodes.
Correct Answer
A. True
Explanation
Subdermal needle electrodes are inserted beneath the skin, while scalp electrodes are placed on the surface of the scalp. The impedance of an electrode refers to its resistance to the flow of electrical current. Since subdermal needle electrodes are inserted deeper into the tissue, they encounter more resistance compared to scalp electrodes, which are closer to the surface. Therefore, the statement that the impedances of subdermal needle electrodes are typically higher than scalp electrodes is true.
41.
Where is the best place to put a ground electrode in order to reduce any stimulation artifact.
Correct Answer
A. Between stimulation and recording electrodes
Explanation
The best place to put a ground electrode in order to reduce any stimulation artifact is between the stimulation and recording electrodes. Placing the ground electrode in this position helps to minimize the interference caused by the stimulation, as it provides a direct pathway for the electrical current to flow and prevents it from affecting the recording electrodes. This placement ensures that the artifact is reduced and the recorded signals are more accurate.
42.
The cortical grid is made of what type of metal?
Correct Answer
A. Platinum
Explanation
The cortical grid is made of platinum.
43.
What is the electrical line frequency in the operating rooms in Europe?
Correct Answer
A. 50Hz
Explanation
In Europe, the electrical line frequency in operating rooms is 50Hz. This means that the alternating current (AC) power supplied to the operating rooms is oscillating at a frequency of 50 cycles per second. This frequency is standard in Europe and is used for various electrical devices and systems, including those in operating rooms. It is important to have a consistent and reliable frequency for the proper functioning of electrical equipment and to ensure the safety of patients and healthcare professionals.
44.
Electrocochleogram (ECochG) consists of combinations of which responses?
Correct Answer
A. Cochlear MicropHonic (CM), Summating Potentials (SP), and auditory nerve compound action potentials
Explanation
The correct answer is Cochlear Microphonic (CM), Summating Potentials (SP), and auditory nerve compound action potentials. These are the combinations of responses that make up the Electrocochleogram (ECochG). The CM is a low-frequency response generated by the outer hair cells in the cochlea, the SP is a mid-frequency response generated by the inner hair cells and auditory nerve fibers, and the auditory nerve compound action potentials are high-frequency responses generated by the auditory nerve fibers. Together, these responses provide valuable information about the function of the cochlea and auditory nerve.
45.
Click stimulators should be delivered unilaterally or bilaterally?
Correct Answer
A. Unilaterally
Explanation
Unilaterally refers to the delivery of click stimulators on one side only. This means that the stimulators are applied to either the left or right side of the body. Bilaterally, on the other hand, would mean that the stimulators are applied to both sides simultaneously. Without further context, it is difficult to determine the specific circumstances or reasons for choosing one approach over the other.
46.
What is the recommended bandpass filter settings for BAEP recordings?
Correct Answer
A. 10-30Hz to 2500-3000Hz
Explanation
The recommended bandpass filter settings for BAEP (Brainstem Auditory Evoked Potential) recordings are 10-30Hz to 2500-3000Hz. This range allows for the filtering of unwanted low-frequency and high-frequency noise, while still capturing the relevant auditory signals within the specified frequency range.
47.
The filter roll-off for BAEP should not exceed what values for low and high frequency filters?
Correct Answer
A. 12dB/octave for low frequency filter & 24dB/octave for high frequency filter
Explanation
The filter roll-off for BAEP should not exceed 12dB/octave for the low frequency filter and 24dB/octave for the high frequency filter. This means that the rate at which the filter attenuates the frequencies beyond its cutoff point should not be steeper than these values. A steeper roll-off can result in unwanted distortion or artifacts in the filtered signal, compromising the accuracy and reliability of BAEP measurements. Therefore, it is important to adhere to these specific roll-off values to ensure optimal filtering in BAEP testing.
48.
How many trials should be averaged for BAEP recordings?
Correct Answer
A. 1000-4000
Explanation
The range of 1000-4000 trials should be averaged for BAEP recordings. This range is likely determined based on the specific requirements and characteristics of BAEP recordings. Averaging a large number of trials helps to reduce the noise and improve the signal-to-noise ratio, resulting in more accurate and reliable recordings. However, averaging too few trials may not provide enough data for a clear and consistent signal. Therefore, the range of 1000-4000 trials is considered appropriate for obtaining meaningful BAEP recordings.
49.
The most prominent component of the electrocochleogram (ECochG), i.e. the AP, arises from:
Correct Answer
A. Primary auditory nerve fibers
Explanation
The most prominent component of the electrocochleogram (ECochG), i.e. the AP, arises from the primary auditory nerve fibers. This is because the ECochG measures the electrical activity generated by the auditory system in response to sound stimuli. The primary auditory nerve fibers are responsible for transmitting auditory information from the cochlea to the brain, making them the main source of the AP component in the ECochG.
50.
The first component of BAER does not arise in the brainstem but the auditory nerve.
Correct Answer
A. True
Explanation
The first component of BAER, which stands for Brainstem Auditory Evoked Response, does not originate in the brainstem but in the auditory nerve. This means that the initial response to auditory stimuli is generated in the auditory nerve before it reaches the brainstem for further processing. This distinction is important in understanding the pathway of auditory information and how it is transmitted from the ear to the brain.