Neuromodulation using ultra low frequency current waveform reversibly blocks axonal conduction and chronic pain

Area of Science:

• Neuroscience
• Biomedical Engineering
• Pain Management

Background:

• Chronic pain is a global health issue, often managed with opioids, which carry risks of side effects and abuse.
• Electrical neuromodulation presents an alternative analgesic strategy, but direct current can cause tissue damage.
• Ultra low frequency (ULF) biphasic current is a novel waveform for neuromodulation.

Purpose of the Study:

• To investigate the efficacy of ULF biphasic current for nerve conduction block and analgesia.
• To explore the mechanisms underlying ULF current-induced nerve block.
• To evaluate the therapeutic potential of epidural spinal ULF neuromodulation in chronic pain patients.

Main Methods:

• Anesthetized rats and an animal model of neuropathic pain were used to study nerve fiber conduction block.
• Computational modeling was employed to elucidate the mechanism of ULF current action.
• A clinical trial involving patients with chronic leg and back pain assessed the analgesic effects of epidural ULF currents.

Main Results:

• ULF biphasic current rapidly and reversibly blocked conduction in over 85% of spinal sensory nerve fibers in rats.
• Sustained ULF currents induced a slower, reversible conduction block by accumulating extracellular potassium.
• Epidural spinal ULF neuromodulation in patients resulted in a 90% pain reduction after 2 weeks, with effects largely reversing after electrode removal.

Conclusions:

• Epidural spinal ULF neuromodulation is a safe and effective therapy for chronic pain.
• This neuromodulation technique offers a reversible alternative to long-term pain management strategies.
• Further research into ULF neuromodulation could lead to new treatments for debilitating chronic pain conditions.