| Nerve Conduction Studies (NCS) |
Records action potentials conducted by nerves for quantification of motor, sensory, and mixed nerve functional status |
Varies depending on nerve studied |
Can differentiate between mononeuropathy and polyneuropathy. NCS is operator dependent and small sensory nerves are difficult to record. Additionally, incorrectly placed needle electrodes may not provide valuable information. Cannot be used to predict nerve injury recovery. |
[@138404; @138462] |
| Electromyogram (EMG) |
Records electrical activity of skeletal muscles whereby shape and frequency of action potentials describe functional status of motor nerves |
50-60m/s (also varies by nerve) |
Deeper muscles require intramuscular wires. May not be suitable in young populations (infants, young children). Preferable in patients with low body fat.
CPT - 95860 |
[@138409; @138411; @138463] |
| Magnetic Resonance Neurography (MRN) |
MRI evaluation of nerve structure |
No evidence of nerve injury |
Difficult to differentiate nerves and vasculature. Also difficult to assess nerve regeneration from chronic degeneration. Not well tolerated by children. It is the gold standard for compressive neuropathy. Faster to perform than EMG. |
[@138415; @138416; @138417; @138464] |
| Ultrasound |
Provides anatomic imaging of nerves. |
No evidence of nerve injury |
Better visualization of smaller nerves and better tolerated in patients. |
[@138464] |