EMG EMG Documentation & Reporting 1 — Questions and Answers
Question 1: According to AANEM guidelines, which elements are required in a complete EMG/NCS report?
- Patient demographics, clinical indication, detailed NCS data with normal values, needle EMG findings by muscle, and an electrodiagnostic impression correlating findings to the clinical question (Correct answer)
- Only the electrodiagnostic impression and a list of muscles tested
- NCS waveform images with patient name and date only
- A summary paragraph without individual muscle or nerve data
Correct answer: Patient demographics, clinical indication, detailed NCS data with normal values, needle EMG findings by muscle, and an electrodiagnostic impression correlating findings to the clinical question
AANEM guidelines require a complete report including patient demographics, clinical indication, all NCS numeric data with normal comparator values, individual muscle needle EMG findings, and a synthesizing impression.
Question 2: When documenting needle EMG findings, which four key parameters should be recorded for each muscle examined?
- Insertional activity, spontaneous activity at rest, motor unit potential morphology, and recruitment pattern (Correct answer)
- Amplitude, latency, conduction velocity, and F-wave latency
- Fibrillation grade, MUAP duration, polyphasia percentage, and CMAP amplitude
- Pain level, muscle depth, needle gauge, and examination duration
Correct answer: Insertional activity, spontaneous activity at rest, motor unit potential morphology, and recruitment pattern
Standardized needle EMG reporting documents insertional activity, rest spontaneous activity, MUP morphology (amplitude, duration, phases), and recruitment pattern for each muscle.
Question 3: What does a grading of '2+' fibrillation potentials indicate in standardized EMG reporting?
- Fibrillation potentials present in more than 2 but fewer than 6 areas of the muscle, persisting throughout the recording (Correct answer)
- Only one fibrillation potential seen in the entire muscle
- Fibrillation potentials in all areas of the muscle with high frequency
- Occasional fibrillation potentials seen in only one needle position
Correct answer: Fibrillation potentials present in more than 2 but fewer than 6 areas of the muscle, persisting throughout the recording
Using the AANEM 0–4 grading scale, 2+ fibrillations indicates potentials present in 3–5 areas of the muscle, reflecting moderate active denervation.
Question 4: In an EMG report, the term 'reduced recruitment' most accurately refers to which finding?
- Fewer motor units firing than expected for the level of patient effort, indicating a loss of motor axons or upper motor neuron inhibition (Correct answer)
- Motor units firing too rapidly before additional units are activated
- Motor units that are excessively polyphasic during voluntary contraction
- Early activation of high-threshold motor units at minimal effort
Correct answer: Fewer motor units firing than expected for the level of patient effort, indicating a loss of motor axons or upper motor neuron inhibition
Reduced recruitment means fewer MUPs are activated for a given force level than expected, reflecting axon loss (neurogenic) or upper motor neuron pathology limiting voluntary drive.
Question 5: Which statement about documenting conduction velocity in a motor NCS report is correct?
- Conduction velocity should be calculated between two proximal stimulation sites and reported in meters per second along with the segment measured (Correct answer)
- Conduction velocity is measured between the stimulating and recording electrodes for distal stimulation only
- Conduction velocity is not required if distal latency is within normal limits
- Conduction velocity should be reported in milliseconds per meter
Correct answer: Conduction velocity should be calculated between two proximal stimulation sites and reported in meters per second along with the segment measured
Motor conduction velocity requires two proximal stimulation sites; the velocity (m/s) is calculated from the difference in latencies divided by the distance between stimulation sites for that segment.
Question 6: Why is it important to include temperature documentation in an EMG/NCS report?
- Cool limb temperature slows nerve conduction velocity and prolongs latencies, which can mimic neuropathy if not documented and corrected (Correct answer)
- Temperature affects only needle EMG findings, not nerve conduction studies
- Temperature documentation is required by CMS only for pediatric patients
- Warm temperature increases CMAP amplitude and can mimic myopathy
Correct answer: Cool limb temperature slows nerve conduction velocity and prolongs latencies, which can mimic neuropathy if not documented and corrected
Cool temperature reduces conduction velocity and prolongs latencies (approximately 2 m/s per 1°C), potentially producing false-positive findings; documenting and correcting for temperature ensures valid interpretation.
EMG EMG Documentation & Reporting 1
According to AANEM guidelines, which elements are required in a complete EMG/NCS report?