Procedure

Nerve Conduction Velocity

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Nerve Conduction Velocity, Nerve Conduction Studies, Nerve Conduction Study

  • Indication
  1. Tests integrity of Peripheral Nerve myelin and axon
  2. Differentiates Neuropathy causes
    1. Distribution (single nerve or diffuse involvement)
      1. See Peripheral Neuropathy Causes
      2. Mononeuropathy (e.g. Carpal Tunnel)
      3. Polyneuropathy (e.g. Diabetic Neuropathy)
    2. Component of nerve involved (see below)
      1. Neuronal or Axonal Neuropathy
        1. EMG slowed out of proportion to Nerve Conduction
      2. Demyelinating or infiltrative Neuropathy
        1. Nerve Conduction slowed out of proportion to EMG
  • Interpretation
  1. Axonal Neuropathy (EMG slowed more than NCS)
    1. Herpes Zoster
    2. Diabetes Mellitus
    3. Malignancy, Lymphoma, Myeloma, Porphyria
    4. Polycythemia Vera
    5. Tabes Dorsalis
    6. Acromegaly
    7. Primary Biliary Cirrhosis
    8. Uremia
    9. Hypothyroidism
    10. Sarcoidosis
    11. Vitamin B12 Deficiency
    12. Toxin exposure (Arsenic, Alcohol)
    13. Medications
      1. Hydralazine
      2. Metronidazole
      3. Disulfiram
      4. Isoniazid
      5. Nitrofurantoin
      6. Thallium
      7. Cisplatin
      8. Gold
      9. Mercury
      10. Dapsone
  2. Demyelinating or infiltrative Neuropathy (NCS slowed)
    1. Guillain-Barre Syndrome
    2. Diabetes Mellitus
    3. Leprosy
    4. Diphtheria
    5. Hypothyroidism
    6. Fabry Disease
    7. Polyarteritis Nodosa
    8. Amiodarone
    9. Liver Disease
    10. Rheumatoid Arthritis
  • References
  1. Pryse-Phillips in Noble (2001) Primary Care, p. 1579