Decision Making

The ultimate responsibility for all aspects of the EMG laboratory examination rests with the electromyographer. However, candidates for the BRETC registration examination are expected to be able to function independently in all phases of nerve conduction studies. For the purpose of the examination candidates will be given common neuromuscular disorder case(s) and decisions about appropriate techniques and which nerves should be tested must be made by the technologist, give the patient’s history and clinical findings.

Anatomy and Physiology

All candidates are expected to know: Neuroanatomy and functional anatomy of the limbs, head, neck and lower back as it related to EMG technology. Basic nerve and muscle physiology as it pertains to excitation and propagation of action potentials in peripheral nerves, neuromuscular junction transmission and the electrochemical/mechanical coupling in skeletal muscle. The type of nerve(s) and their connections responsible for phenomena observed in EMG technology, e.g.: explain the pathways needed to evoke an H reflex. The essential nature of common neuromuscular problems tested in the EMG laboratory.

Electronic and Machine Considerations

Essential knowledge and understanding (to include how altering the machine parameters affects waveforms) about:

  • Gain (sensitivity)
  • Sweep speed
  • Filters (high and low pass)
  • Averaging
  • Calibrations
  • Stimulating electrode and stimulating parameters
  • Recording electrodes
  • Impedance
  • Shock artefact 60 Hz artefact
  • Grounding (current limiters and signal isolation)
  • Electrical safety
  • Ohm’s law
  • Leakage current

Patient Considerations:

  • Good beside manner and patient handling skills
  • Appropriate history taking
  • Proper skin preparation
  • Consideration of patient comfort during testing
  • Management of limb temperature and its effect on nerve conductions
  • Management of muscle artifact
  • Ability to deal with limb edema, intravenous sites, etc.
  • Understanding the effect of age
  • Adequate infection control techniques regarding cleaning, disinfection and sterilization of lab equipment

Nerve Conduction Studies Candidates will be evaluated on points previously stated and in addition:

  • General knowledge of normal electrophysiological values and therefore recognition of abnormal values
  • Recording electrode placement
  • Stimulation
  • Quality of traces
  • Accuracy of latency, amplitude, distance and velocity measurement (manual measurements may be asked for)
  • Electrode handling and preparation
  • Stimulus spread
  • Manual conduction velocity calculations

Needle EMG Consideration Candidates must have knowledge about:

  • Machine set up for Electromyography
  • Types and properties of needle electrodes
  • Infection control techniques: sterilization, handling, storage and disposal of needle electrodes and indications for wearing gloves, masks, gowns

Motor Nerves

Be prepared to perform nerve conduction studies on: Median, ulnar, radial, musculocutaneous, peroneal, femoral, facial, anomalies (Questions on the written examination will not be restricted to these motor nerves – see Anatomy section)

Sensory Nerves

Be prepared to perform nerve conduction studies on: Median, ulnar radial, musculocutaneous, sural, superficial peroneal, medial and lateral plantars, saphenous (Questions on the written examination will not be restricted to these sensory nerves – see Anatomy section)

Additional Techniques

Know: Myasthenia and Myasthenic Syndrome studies (proximal and distal techniques), F responses, Axon reflexes, H reflexes, Blink reflexes.

Acknowledgements

Prepared by Helen Brooks & Tony Parkes