Selective Decrease in Allodynia With High‐Frequency Neuromodulation via High‐Electrode‐Count Intrafascicular Peripheral Nerve Interface After Brachial Plexus Injury

• Published in: Neuromodulation (Malden, Mass.) Vol. 22; no. 5; pp. 597 - 606
• Main Authors: Duncan, Christopher C., Kluger, David T., Davis, Tyler S., Warren, David J., Page, David M., Hutchinson, Douglas T., Clark, Gregory A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Limited 01.07.2019
• Subjects: Aged; Allodynia; Anesthetics; Brachial plexus; Brachial Plexus - injuries; Brachial Plexus - physiology; Chronic pain; Electrodes; Electrodes, Implanted; Humans; Hyperalgesia - diagnostic imaging; Hyperalgesia - physiopathology; Hyperalgesia - therapy; Male; Median nerve; Median Nerve - physiology; nerve block; Nervous system; Neuromodulation; neuropathic pain; Pain; Pain perception; peripheral nerve stimulation; Peripheral nerves; Peripheral Nerves - physiology; Transcutaneous Electric Nerve Stimulation - instrumentation; Transcutaneous Electric Nerve Stimulation - methods; Allodynia; neuromodulation; neuropathic pain; nerve block; peripheral nerve stimulation
• ISSN: 1094-7159; 1525-1403
• DOI: 10.1111/ner.12802

Objectives Kilohertz high‐frequency alternating current (KHFAC) electrical nerve stimulation produces a reversible nerve block in peripheral nerves in human patients with chronic pain pathologies. Although this stimulation methodology has been verified with nonselective extrafascicular electrodes, the effectiveness of producing a selective nerve block with more‐selective intrafascicular electrodes has not been well documented. The objective of this study was to examine whether intrafascicular electrodes can block painful stimuli while preserving conduction of other neural activity within the implanted nerve. Materials and Methods We analyzed the effects of various stimulation waveforms delivered through Utah Slanted Electrode Arrays (USEAs) implanted in the median nerve of a male human subject with a left brachial plexus injury. We compared KHFAC stimulation with a sham control. Results KHFAC stimulation through USEA electrodes produced a reduction in pain sensitivity in the palmar aspect of the left middle finger. KHFAC had limited effects on the patient's ability to feel tactile probing in the same area or move the digits of his left hand. Other tested stimulation parameters either increased or showed no reduction in pain. Conclusions KHFAC stimulation in peripheral nerves through intrafascicular electrodes demonstrated a selective reduction in pain sensitivity while preserving other nerve functions. This treatment may benefit patient populations who have chronic pain originating from peripheral nerves, but who do not want to block whole‐nerve function in order to preserve sensory and motor function reliant on the implanted nerve. Furthermore, KHFAC may benefit patients who respond negatively to other forms of peripheral nerve stimulation therapy.