Download CNIM - ABRET A+ Graded Practice Exam Questions With 100% Verified And Correct Answers 2025 and more Exams Advanced Education in PDF only on Docsity!
CNIM - ABRET A+ Graded Practice Exam
Questions With 100% Verified And
Correct Answers 2025
Cavities inside the skull - Correct Answer-Anterior/middle/posterior fossa Cranial bones - Correct Answer-Frontal, occipital, sphenoid, ethmoid (unpaired). Parietal & temporal (paired). Mental protuberance - Correct Answer-chin bone MCA supply of the cerebral cortex - Correct Answer-Hand + face/mouth/auditory Cranial nerves - Correct Answer--12 pairs (Mixed fibers: sensory/motor/both). -Emerge @ irregular intervals from the brain. -Nuclei displacement: Motor = medial Sensory = lateral Meckle's Cave - Correct Answer-Depression in the medial middle fossa where CN V ganglion sits Low frequency sounds - Correct Answer-@ apex of cochlea Area of spine w/ small pedicles, long spinous process, large inter-vertebral foramen - Correct Answer-Thoracic Neuroforamen - Correct Answer-Opening w/in the spinal canal for nerve roots to enter the SC Firm outer layer of the disc - Correct Answer-Annulus fibrosis Syrinx - Correct Answer-Fluid-filled cavity @ center of the SC Spinal cord ends @ the level btwn: - Correct Answer-L1-L2 vertebrae (Conus Medullaris) Blood supply to the SC consists of: - Correct Answer-1 ASA for both MEP tracts Hydrostatic pressure - Correct Answer-Depends on body position Structural functional anatomy may be altered by: - Correct Answer-Previous lesions, current, plasticity, pressure
Glia cell - Correct Answer-Comes from the Greek word "glue" Large diameter nerve fiber (vs. small diameter) - Correct Answer--Recruited 1st w/ INC'd stim intensity -Higher conduction velocity -More vulnerable to hypoxia & pressure Δ's Synaptic transmission, and/or Δ's in thalamocortical projections, produce - Correct Answer-Cortical potentials Peripheral nerve sensitivity - Correct Answer-Least sensitive to injury (more sensitive = SC grey/white mater, cortical grey matter) Cavernous angiomas - Correct Answer-Multi-lobulated lesions containing hemorrhage Geriatric population: prevalence of temporal bone hyperostosis - Correct Answer-10- 15% Presbycusis - Correct Answer-High freq hearing loss; gradually occurs in older individuals Most commonly injured CN - Correct Answer-Facial nerve (VII) Burst fracture - Correct Answer--Break in the vertebra -Failure of anterior & middle vertebral columns -Caused by violent compressive event (fall, MVA) Excessive neck flexion in sitting position - Correct Answer-Quadraparesis (due to ischemia in upper T-spine) Lhermittes Sign - Correct Answer-Shocking sensation that occurs throughout the body during neck flexion Central Cord Syndrome (CCS) - Correct Answer--Sacral sparing -Loss of sensory/motor fx @ level of injury -Disruption of grey matter (+) Babinski Sign could indicate - Correct Answer--severe [UMN] SC trauma -abnml PTN SSEPs Hoffman's Reflex (1918) - Correct Answer-Palmar flexion of the thumb when the distal phalanx of the middle finger (of the same hand) is rapidly stroked A nml curve of the lumbar spine taking place @ 1-2 y/o - Correct Answer-Kyphosis Scoliosis progression in peds - Correct Answer-More likely in girls > boys
Propofol - Correct Answer-(GABA agonist) -SSEP/BAER = INC latency -EEG = slowing Etomidate - Correct Answer-(GABA agonist) -SSEP/MEP: INC amp -EEG: slowing dexmeditomidine (Precedex) - Correct Answer-(α2-adrenergic antagonist) -mimics nml sleep; awakening --> most nml neuro exam -associated w/ unconsciousness (NOT amnesia) -DEC MEP ampmlitudes Fentanyl - Correct Answer-(μ-opioid agonist) -SSEP: mild effect on lat/amp -EEG: slowing, diffuse Δ -high dose maintenance --> may not result in EEG burst depression Succinylcholine - Correct Answer-depolarizing muscle relaxant Rocuronium - Correct Answer-non-depolarizing muscle relaxant Monitoring mm relaxation is done via TOF. How is relaxation measured? - Correct Answer-By counting the # of mm responses to 4 stimuli @ 2 Hz Barbiturate effect on EEG - Correct Answer-burst suppression phenytoin (Dilantin) - Correct Answer-anticonvulsant (NaV channel blocker) -should be excluded before ECoG for inter-ictal discharges Advantages of general anesthesia during CEA - Correct Answer--prevents pt mvmnt; provides brain protection & rapid BP control -does NOT provide measurement of brain activity Anesthesia optimal BIS range - Correct Answer-40- Which least affects the neurogenic response to SC stimulation? - Correct Answer- Anesthetic agents > NMBs, hardware insertion, current shunting from irrigation Anesthesia is started & pt is intubated. No MEP responses for 15-20 min after induction. Which muscle relaxant was used? - Correct Answer-Succinylcholine Latency Δ's are caused by effects on - Correct Answer-Na+ channel receptors Etomidate/ketamine/methohexital are used in low doses to elicit/enhance: - Correct Answer-seizure foci during EcoG
DEC HCT - Correct Answer-INC RBC velocity Nitroprusside - Correct Answer-(breaks down to NO --> vasodilator) DEC's BP Unstable BP effects on cortical SSEPs - Correct Answer-fluctuating amplitudes Glucose is monitored & treated during surgery bc: - Correct Answer--high/low BG levels = associated w/ worsened neurological injury -Glc produces intracellular acidosis during ischemia Pt presentation for acoustic neuroma: - Correct Answer-hearing loss, HA, unsteady gait Most important step to setting up BAERs? - Correct Answer-placing foam inserts Least important considerations during intra-op BAERs - Correct Answer-Anesthetic considerations < BP, local cooling, core body temp BAER waveforms cannot be recorded in the following conditions: - Correct Answer-- bone drilling -30 dB pe SPL (intensity levels) -"kinking" of the sound delivery tube BAER stim/RR - Correct Answer--<20 Hz (optimal amplitude) -10-19 Hz range -31.1 (acceptable) -NOT divisible by 60 Hz
30 Hz = INC lat + DEC amp BAER troubleshooting: pt w/ conductive hearing loss - Correct Answer-INC stim intensity First 3 possible waveform components @ onset of BAERs - Correct Answer-cochlear microphonics, summating potential, AP of CN VIII BAER waves III-V are generated at - Correct Answer-Midbrain-pons area III = cochlear nucleus-SOC IV = SOC-decussation-LL V = IC Propofol effects on BAERs: - Correct Answer--latencies: INC I/III/V -no Δ in amplitudes AICA vasospasm: effects on BAER - Correct Answer-complete loss of all waves EXCEPT cochlear microphonics
DEC power of Spectral Edge indicates: - Correct Answer-a greater proportion of EEG power @ lower freq's CSA & CDSA - Correct Answer-processed EEG displays Cardiac activity on the CSA/CDSA appears as - Correct Answer-delta activity Fast Fourier Transformation (FFT) - Correct Answer-Mathematical transformation: complex waveform --> simpler, uniform waves EEG will most likely disappear at what temp? - Correct Answer-16 deg C What EEG Δ's would you expect after intra-carotid injection of sodium amytal? - Correct Answer-Ipsi DEC in high freq waves EEG filter, time-base, and sensitivity for monitoring cortical ischemia during a CEA: - Correct Answer-0.3-70 Hz, 15 mm/s, 3 uV/mm Most strokes associated w/ a CEA occur: - Correct Answer-after cross-clamping is released Methods to monitor brain perfusion during CEA: - Correct Answer--intra-op: doppler, angiography -measuring residual "stump" (ICA) pressure CEA surgery: 80% of clamp-related EEG Δ's occur w/in: - Correct Answer-first 1 min Maximum time to expect EEG Δ's following carotid cross-clamping? - Correct Answer- min Pt w/o collateral blood supply during a CEA can suffer post-op deficits if perfusion isn't resolved w/in: - Correct Answer-10 min ECoG: advantage of grid/strip electrodes over "crown of thorns" - Correct 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: - Correct 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) - Correct Answer--repetitive electrographic bursts, slowing, and/or spike-wave activity -occur in response to electrical stimulation @ brain surface
Problems w/ AD's - Correct 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: - Correct 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 - Correct Answer-2.0 MHz TCD: nml waveforms - Correct Answer-have a brisk upstroke TCD: primary quantitative value - Correct Answer-velocity TCD: micro-embolic signals - Correct Answer-have a short duration of < .1 s sEMG: nerve root patterns - Correct 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? - Correct Answer-synchronicity & repetitiveness sEMG trains - Correct 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: - Correct Answer-due to capacitive discharge from the metal Which mm's would be most appropriate to monitor sEMG for L5 & S1 nerve roots? - Correct Answer-PL (L5-S1) & Semimembranosus (L5-S2) If a pedicle screw tests above the accepted threshold? - Correct Answer-Inform surgeon of an acceptable screw value Trigeminal (CN V) sEMG muscles: - Correct Answer-Masseter or Temporalis Facial (CN VII) sEMG muscles: - Correct Answer-Frontalis, Obicularis Oculi/Oris, Mentalis Sensitive stimulator electrode during CN VII recording - Correct Answer-bipolar concentric EMG needle
-Opioids = minor effects on myogenic MEPs -TIVA = most compatible w/ myogenic MEPs (propofol + opioids) -Ketamine = can enhance SSEPs & MEPs
- Halogenated gases = prominently suppress myogenic MEPs
- N2O = marked Δ's in MEPs; can be recorded using "nitrous-narcotic" technique TCeMEP contraindications - Correct Answer--Contraindications = pacemaker, cochlear implants, implanted stimulators, cephalic metal implants -Not absolute contraindications = hx of seizures -Modify accordingly = prior crani or skull fx, skull breach (VP shunt close to stim site) D-waves cannot be recorded below: - Correct Answer-L Inhalation agents affect MEPs how? - Correct Answer-DEC # of I-waves 30-50% DEC in D-wave amplitude, coupled w/ unchanged MEPs, predicts which neurological outcome? - Correct Answer-no changes Lost MEPs w/ D-wave preservation (@ least 50% of baseline amplitudes) during intramedullary SC tumor resection predicts which neurological outcome? - Correct Answer-transient motor deficits TCeMEPs & H-reflexes similarities: - Correct Answer--Measure MN fx associated w/ mm -Require long-duration stimulus and/or trains of stimuli to activate -Sensitive to SC ischemia -Exhibit decline w/ spinal shock Types of reflexes: - Correct Answer--Flexion (withdrawal) -Cremaster (inner thighs) -Bulbocavernosus (SC) -Blink -Stretch H-reflex: stimulation parameters - Correct Answer--Stim intensity = 5-40 mA -ISI = 2-5 s -PW = 700 us --> 1 ms -Analysis Time = >100 ms -Sensitivity = 50-200 uV -Bandpass = Locut 20-100 Hz, Hicut 1000-3000 Hz -Acquisition mode = stimulator, tEMG, or EP H-reflex: mm's & nerve roots - Correct Answer--C5-C6 musculocutaneous nerve = BIC -C6/C7/C8 radial = TRI, brachioradialis -C6/C7/C8/T1 median = FCR -L2/L3 obturator = Adductors
-L3/L4 femoral = Quads -S1/S2 = Gastroc H-reflex is measured by - Correct Answer--Latency of the 2nd peak of a triphasic response -Max amp measured: peak <--> trough -Selecting the best response after 5-10 trials Why are SSEPs and MEPs used simultaneously? - Correct Answer-SC damage can occur in 1 tract --> cause loss of MEPs but not SSEPs, vice versa Nerve fibers activated during SSEP recordings carry out what type of info? - Correct Answer-Proprioception & vibrotactile sensation SSEP effects: pt w/ a body temp of 30 deg C will have - Correct Answer-INC'd latencies SSEPs are highly variable & less reliable in pt's w/ - Correct Answer-neuromuscular disease When SSEPs fail, the time to irreversible injury is: - Correct Answer-inversely related to blood flow Charcot-Marie Tooth Disease - effect on SSEPs? - Correct Answer-PNS disease; results in INC'd latencies Value of pre-op SSEP baselines? - Correct Answer-Useful for establishing the integrity of the somatosensory pathways prior to onset of anesthesia Pre-op SSEP baseline values are essential to IONM bc: - Correct Answer-Absolute boundaries for EPs obtained intra-op are not available Pre-positional recordings make good baselines for the entire surgical monitoring case. True or false? - Correct Answer-False Spinal potentials are recorded to: - Correct Answer-establish an AP Which SSEP component would be most affected by a tumor in the SC/medulla intersection? - Correct Answer-N The CCT for MN SSEP is: - Correct Answer-P14 --> N MN SSEPs can be a helpful measure of: - Correct Answer-cerebral blood flow What kind of SSEP Δ's would be present during a positioning effect of the L arm? - Correct Answer-DEC amplitude/INC latency/loss of: L Erb's, L subcort, and R cortical
(SSEP) If you cannot evaluate motor twitch: - Correct Answer-INC intensity until maximum peripheral signal A stimulus PW that tends to excite more motor fibers than sensory fibers: - Correct Answer-0.5 ms (50 uS) Significant Δ's in cervical and cortical SSEPs during IONM + adequate stimulation of the median nerve is indicated by: - Correct Answer-No Δ in peripheral responses SSEP stim electrodes - should not be placed: - Correct Answer-Near catheters leading into the heart or great vessels (SSEP) Initial waveform recorded of a near-field potential - Correct Answer-Positive (due to electrotonic dp of the membrane under the recording electrode) To stimulate both PTN asynchronously: - Correct Answer-Need to delay the 2nd stimulator Troubleshoot - artifact in a subcortical channel: - Correct Answer-use a spare C5S electrode Advantages of Dural- or Direct-SSEP SC recordings: - Correct Answer-Waveforms are higher in amplitude + require fewer responses BAERs and SSEPs monitor pathways in _______% of the brainstem area - Correct Answer-20% To record the compound AP of the MN intra-op, an electrode should be placed at: - Correct Answer-the antecubital fossa Bc generator sites are typically deep w/in anatomical structures, most EPs are considered: - Correct Answer-far-field responses During a MN pre-op study, a pt has discomfort @ the wrist. Stim electrodes = 10 mm gold disk, stim intensity = 20 mA, and PW = 100 uS. Which will most likely reduce the pt's discomfort while maintaining adequate stimulation? - Correct Answer-DEC # of repetitions Although electrocautery can obliterate EP waveforms, IONM should be continued by: - Correct Answer-monitoring raw (unaveraged) data (SSEP) The electrode closest to the post-central gyrus is: - Correct Answer--trace after phase reversal occurs -central sulcus located btwn traces
To accurately represent the amplitude of an EP waveform, a match must be made btwn:
- Correct Answer-Signal size <--> vertical capacity of the digitizer A 10-bit A/D converter has how many discrete voltage values in its range? - Correct Answer- An EP recording system should allow averaging of: - Correct Answer-@ least 4000 trials (sweeps) What is an appropriate filter for a short-latency SSEP cortical response? - Correct Answer-10-3000 Hz SC EP's are best recorded using a LFF setting of 100 Hz. This setting is preferred bc, relative to cortical SSEPs, SC EP's are: - Correct Answer-of relatively short duration SSEP filter settings: cortical vs. peripheral responses? - Correct Answer-narrower for cortical > peripheral responses Lowering the SSEP HFF/hicut filter from 500 Hz --> 200 Hz may cause cortical peaks to: - Correct Answer-Appear longer in latency When monitoring SSEPs during a critical moment in a study, Δ'ing the HFF: - Correct Answer-May lead to false interpretation of the data Effect HFF reduction on SSEP latency? - Correct Answer-INC's latencies Aliasing - Correct Answer--Erroneous representation of an analog signal by digital values -Addition of power @ a freq NOT in the OG signal Notch Filter use causes: - Correct Answer-ringing artifact Electrodes - IM vs Surface - Correct Answer--IM = INC sensitivity for detecting "near field" motor unit potentials -Surface = INC CMAP amplitude & morphology In the presence of radio frequency energy, electrodes in the OR act like: - Correct Answer-an antenna Why is platinum used in epidural electrodes? - Correct Answer-Other metals are toxic when current is applied due to ions Platinum epidural electrodes - Correct Answer-Reduce neurotoxicity Subdermal needle electrodes must be inserted symmetrically over homologous brain areas to avoid: - Correct Answer-Artificial amplitude asymmetries
Most sources of electrical artifact emit noise into the air: - Correct Answer-the same way a radio transmitter does The assumption that responses of excessive amplitude are likely to contain artifact forms the basis for: - Correct Answer-artifact rejection Noise reduction technique that best reduces EKG artifact - Correct Answer-artifact rejection 60 Hz artifact would most likely be caused by - Correct Answer-an infusion pump Least likely to cause electrical interference in the OR: - Correct Answer-Pneumatic drill The (+) input of a differential amplifier is also called the: - Correct Answer-non-inverting input Amplifier input impedance of a differential amplifier must be: - Correct Answer-at least 10 MOhms If your initial signal amplitude is 0.5 uV inside a background noise of 2 uV, what will be the SNR after 400 averages? - Correct Answer- If you have a 5 uV signal amplitude & 20 uV noise amplitude, how many averages would you need to get a 2:1 SNR? - Correct Answer- If one has a SNR of 1:2, averaging 64 responses will: - Correct Answer-improve the ratio 4: If you receive a shock from the chassis of your machine during monitoring, you should first: - Correct Answer-disconnect the pt EP equipment in the OR should have current-limiting present in every lead to allow for a max leakage current thru ea pt lead of: - Correct Answer-10 uA (.01 mA) What is the max allowable chassis leakage current? - Correct Answer-100 uA (0.1 mA) Purpose of isolated amplifier inputs: - Correct Answer-Prevent flow of stray currents thru connecting lines to the pt One fx of the circuitry in an isolated input board is to protect the pt from electrical shock by limiting current flow to no more than: - Correct Answer-20 uA The key element of any amplifier: - Correct Answer-The transistor (converts small input current --> large output current) Sampling - Correct Answer-Process of converting an analog signal --> digital domain
Quantization error - Correct Answer-The difference btwn the "real" analog signal and the digitized signal in A/D conversion The gain of a differential amplifier is defined as: - Correct Answer-(voltage out) / (voltage in) Minimum bandpass required for an EP system - Correct Answer-0.1-5000 Hz The sensitivity setting on an amplifier set to produce a vertical deflection of 1 cm w/ an input of 10 mV: - Correct Answer-1 mV/mm The gain of an amplifier set to give an output signal of 1 V for an input of 10 mV is - Correct Answer-100, A differential amplifier w/ a gain of 1,000,000 has a 0.2 uV signal @ its (+) input and 0. uV signal @ its (-) input. What is the output? - Correct Answer-Downward peak = 0.6 uV Required horizontal resolution of an EP system - Correct Answer-20 uS/data point or less Selecting horizontal parameters of analysis (Nyquist Frequency) - Correct Answer- Sampling rate should be at least 2x greater than the highest freq in the signal 10 kHz sampling rate: shortest sine wave resolved = - Correct Answer-0.2 ms Which time constant would be more effective for cutting out low freq noise from a signal? - Correct Answer-10 ms What is the freq of a signal if, in a 30 ms sweep, the interval btwn ea cycle of the signal is .3 ms? - Correct Answer-33 kHz What is the period of a 200 Hz signal? - Correct Answer-5 ms Craniotomy - BP management - Correct Answer-normotension CEA - vascular complications - Correct Answer--hyper-/hypo-perfusion -thrombosis, embolism In severely elevated ICP (i.e., herniation), which modalities are not affected? - Correct Answer-cortical SSEPs, BAERs, mid-latency auditory responses True/false? 50% drop from pre-cross-clamp baselines indicates hypoperfusion - Correct Answer-False; most pt's tolerate 70% DEC Goal of MVD: - Correct Answer-Place Ivalon/Teflon pad btwn offending vessel & nerve
Harrington rod instrumentation - distraction on the SC cannot be tested by what modality? - Correct Answer-dorsal root stimulation Sublaminar wires - provide what type of manipulation to the spinal cord? - Correct Answer-translational corrective forces to the spinal column The primary risk to the spinal cord during Luque instrumentation? - Correct Answer- placement of sublaminar wires Cotrel-Dubousset & Isola instrumentation - Correct Answer--distract, compress, de- rotate spine -restores nml vertebral column alignment Isola spinal instrumentation - uses what type of implants? - Correct Answer- Combination hook & screw method Types of spinal instrumentation - Correct Answer--Luque L-rod w/ sublaminar wires -Cotrel-Dubousset & Isola -Texas Scottish Rite Hospital Steps of IONM - Correct Answer-1) investigate case
- equipment set-up
- pt pre-op asssessment
- baselines
- document
- monitor When preparing a pt for IONM, you want to make sure that wires are ____________ from the sterile field? - Correct Answer-directed away Universal precautions - Correct Answer-Use of PPD/PPE w/ every pt Main source of airborne bacteria in the OR: - Correct Answer-exfoliated skin particles from OR staff The average person sheds skin at a rate of: - Correct Answer-4,000-10,000 cells/min Most frequent source of pt infection in the OR derives from: - Correct Answer-the pt's own endogenous flora According to nursing guidelines, how far do you need to be from the sterile field? - Correct Answer-18" The sterile table w/ instruments & implants in considered sterile in which areas? - Correct Answer--on the table surface
-at/above the table -NOT below the table Semi-critical infectious device - Correct Answer-requires intermediate to high disinfection after ea use Can boiling water be used to sterilize surgical instruments? - Correct Answer-No
