Table 1 Reported effects on nerve injury recovery after electrical stimulation

Hoffman H

Aust. J. Exp. Biol. Med. Sci. (1952)

AC, 6.3 V, 50–100 cycles, 1.5 m A, 0–5,000 Ω variable resistance

Spinal cord injury

Enhanced reinnervation and sprouting

Maehlen J, NjåA

J. Physiol. (1982)

Preganglionic stimulation for 1 h immediately after the partial denervation with 100 pulses at 20 Hz every 25 s

Thoraco-cervical sympathetic trunk transection

Increased rate of sprouting

Nix WA, Hopf HC

Brain Res. (1983)

AC, 0.2 ms duration, frequency of 4 pulses per second (pps), applied (24 h daily) for 4 wks, and stimulation started 1 d postoperatively

Sciatic nerve transection

Improved electrophysiological recovery

Pockett S, Gavin R

Neurosci. Lett. (1985)

AC, proximal stump, 0.1-ms pulses, supramaximal voltage

Sciatic nerve crush

Improvement in toe spread function

McDevitt, et al.

Brain Res. (1987)

DC, 10 µA/cm², Distal cathode, hind paw, field strength ∼100 mV/cm, 100 kΩ resistance, daily for 20 d

Sciatic nerve transection and repair

Enhanced motor axon regeneration

Román GC, et al.

Exp. Neurol. (1987)

DC, distal cathode implantation with a 10-µA for 3 wks

Sciatic nerve transection and repair

Increased number of myelinated axons

Zanakis MF, et al.

Acupunct. Electrother. Res. (1990)

DC, 1.4 µA (about 8 mV/cm field strength) to a nerve cuff

Sciatic nerve crush

Enhanced number of regenerating axons in the distal stump

Kerns JM, et al.

Exp. Neurol. (1992)

DC, 10 µA/cm², Distal cathode

Sciatic nerve crush

No change in sciatic function index (SFI)

Pomeranz B, et al.

Brain Res. (1993)

DC of 10 µA, 200–270 kΩ resistor, stimulation for a month

Sciatic nerve crush

Improved electrophysiological outcomes

Al-Majed AA, et al.

J. Neurosci. (2000)

AC, proximal stump, 0.1 ms,3V, 20 Hz, 1 h immediately after repair and up to 2 wks

Femoral nerve transection and repair

Accelerated motor axons regeneration across repair site after 1 h of stimulation but no further benefits with chronic stimulation

Mendonça CA, et al.

J. Neurosci. Methods (2003)

DC, proximal stump, low-intensity continuous current circuit (1 µA), 1.5 V battery and a 1.3-MΩ resistor for 3 wks

Sciatic nerve crush

Improved SFI

Ahlborn P, et al.

Exp. Neurol. (2007)

AC, proximal stump, square 0.1-ms pulses, 20 Hz, 3–4 V, acute

Femoral nerve transection

Improved motor axon regeneration and behavioral recovery

Geremia NM, et al.

Exp. Neurol. (2007)

AC, proximal stump, 0.1 ms, 3V, 20 Hz, 1 h immediately after repair and up to 3 wks

Femoral nerve transection and repair

Improved sensory axon regeneration with acute stimulation but reduced benefits with chronic stimulation

Singh B, et al.

J. Neurosurg. (2012)

AC, proximal stump, 0.1 ms,3V, 20 Hz, 1 h immediately after repair

Sciatic nerve transection and repair

Improved axon regeneration and target reinnervation

Huang J, et al.

Eur. J. Neurosci. (2013)

AC (3 V, 20 Hz, 20 min) applied proximally to the transected nerve while repairing (2, 4, 12 and 24 wks)

Sciatic nerve transection and delayed repair

Increased motoneurons and sensory neurons regeneration, improvement in CMAP and NCV up to 24 wks of delay

Zhang X, et al.

Mol. Med. Rep. (2013)

AC (3 V, 20 Hz, 1 h) applied proximally to the nerve

Sciatic nerve crush

Improved remyelination, axon diameter and electrophysiological measures

Calvey C, et al.

J. Hand Surg. Am. (2014)

A direct current of 24 V/m (24 mV, DC 1.5 mA), applied across the electrodes for 10 min and 60 min

Sciatic nerve transection and repair

Enhanced behavioral and histological recovery

Xu C, et al.

PLoS One (2014)

AC, proximal stump, 0.1 ms, 3 V, 20 Hz, delayed nerve repair after 1 d, 1 wk, 1 month and 2 months

Sciatic nerve transection and repair at different time points

Improved electrophysiology parameters but the impact reduced with the delay

Thompson NJ, et al.

Dev. Neurobiol. (2014)

AC, short (0.1 ms) pulses at 20 Hz, 1 h immediately before nerve transection

Sciatic nerve transection and repair

Enhanced axon regeneration