EMG:  Available Testing

Our EMG Laboratory offers a wide range of diagnostic testing for disorders of the peripheral nervous system.

Common diagnostic questions referred to our laboratory include:

  1. Focal entrapment or compression neuropathies such as the carpal tunnel syndrome, ulnar neuropathies, Bell's palsy, wrist or foot drop, and radiculopathies.
  2. Generalized peripheral neuropathies.
  3. Motor neuron diseases.
  4. Brachial or lumbosacral plexopathies.
  5. Myopathies.
  6. Disorders of neuromuscular transmission. (e.g. myasthenia gravis)

 

The testing involved varies depending on the complexity of the patient's problem. In general, there are three components to the diagnostic testing offered in our laboratory.

  1. Nerve conduction studies
    A wide variety of motor and sensory nerves can be studied. Motor studies routinely performed in our laboratory include studies of the median, ulnar, radial, femoral, common peroneal, deep peroneal and tibial nerves. Sensory nerve conduction studies routinely performed in our laboratory include testing of the radial, median, ulnar, medial and lateral antebrachial cutaneous nerves of the forearm, sural and superficial peroneal nerves. Other motor and sensory nerves can be studied depending on the patient's clinical presentation.

  2. Needle electromyography
    This involves placing a small (usually 25 mm long, 30 gauge) sterile disposable concentric EMG needle into muscle tissue and assessing the reaction of muscle tissue to needle movement (insertional activity), the presence of electrical activity in muscle tissue at rest (spontaneous activity), as well as the morphology and pattern of recruitment of voluntary motor unit potentials. A wide variety of muscles can be studied; the choice of which muscles are studied depends on the clinical problem.

  3. Specialized tests
    In addition to routine nerve conduction studies and needle EMG, our laboratory offers a number of highly specialized tests including:

    • Central motor conduction and proximal motor studies
    • Somatosensory evoked potentials   (SSEP, SEP)
    • Specialized testing of neuromuscular transmission:
      • Repetitive nerve stimulation (RNS)
      • Single fiber EMG (SFEMG)
    • Facial nerve studies (Bell's palsy)
    • Blink Reflexes
    • Respiratory studies  (Phrenic nerve)
    • Visual Evoked Responses (VER, VEP)

    The decision about which tests are done rests ultimately with the EMG physician.

 

LHSCHealth Professionals

Last Updated February 11, 2009 | © 2007, LHSC, London Ontario Canada