II. Indication
- Tests integrity of Peripheral Nerve myelin and axon
- Differentiates Neuropathy causes
- Distribution (single nerve or diffuse involvement)
- See Peripheral Neuropathy Causes
- Mononeuropathy (e.g. Carpal Tunnel)
- Polyneuropathy (e.g. Diabetic Neuropathy)
- Component of nerve involved (see below)
- Neuronal or Axonal Neuropathy
- EMG slowed out of proportion to Nerve Conduction
- Demyelinating or infiltrative Neuropathy
- Nerve Conduction slowed out of proportion to EMG
- Neuronal or Axonal Neuropathy
- Distribution (single nerve or diffuse involvement)
III. Interpretation
-
Axonal Neuropathy (EMG slowed more than NCS)
- Herpes Zoster
- Diabetes Mellitus
- Malignancy, Lymphoma, Myeloma, Porphyria
- Polycythemia Vera
- Tabes Dorsalis
- Acromegaly
- Primary biliary Cirrhosis
- Uremia
- Hypothyroidism
- Sarcoidosis
- Vitamin B12 Deficiency
- Toxin exposure (Arsenic, Alcohol)
- Medications
- Demyelinating or infiltrative Neuropathy (NCS slowed)
IV. References
- Pryse-Phillips in Noble (2001) Primary Care, p. 1579