Peripheral Neuromodulation to Treat Postamputation Pain

Abstract

Some of the more common peripherally mediated pain disorders are postamputation stump pain and phantom pain. These disabling conditions have proven difficult to treat. Here we aim to illustrate an option to treat postamputation pain using peripheral neurostimulation techniques. Traditional peripheral neuromodulation techniques use standard stimulation parameters and work by stimulation of nerve tissues which are then felt by the patient as a tingling sensation or paresthesia. Recently introduced high-frequency (10 kHz) electrical nerve block [HFAC (high-frequency alternating current) block] via a surgically implanted peripheral nerve cuff electrode results in true conduction block which actually blocks action potentials emanating from the painful neuroma and thus suppresses pain without tingling or paresthesia felt by the patient. In a recently completed 10-patient pilot study, the average pain level decreased from a score of 5.7 to 1.4 (out of 10) after HFAC block therapy with 85% of all testing sessions yielding a >50% pain reduction; a very significant reduction in the use of opioid and other analgesics was also noted, with all tested patients either stopping or decreasing their analgesic intake significantly. Patients achieved meaningful and significant pain reduction throughout the study, and patients who had phantom pain (in addition to stump pain) that responded to local anesthetic injections also responded favorably with HFAC block, presumably because in these particular patients, the phantom symptoms were peripherally generated. Each of the tested patients reported that HFAC block provided the most significant amount of pain reduction they had ever experienced when compared to other pain modalities tried since their amputations. The high-frequency electric nerve block technique is currently investigational pending FDA clearance. The next step for this modality is a pivotal trial, with the goal of having this therapy available to the mass market upon FDA clearance.

Peripheral Nerve Stimulation in Pain Management: A Systematic Review

“…These traditional PNS modalities cause paresthesia during stimulation. Kilgore and Bhadra (52) introduced a high-frequency (HF-10 kHz) alternating current nerve block, which was then used to deliver paresthesia-free stimulation via a surgically implanted peripheral nerve cuff electrode (53). HF-10 nerve stimulation causes a complete depolarizing nerve block that is similar to that provided by local anesthetics.…”

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

“…Because previous reports documented that electrical nerve blocks were effective in patients who responded positively to an injection of a chemical nerve block , we assessed our patient's response to lidocaine injection in the median nerve near the wrist of the implanted arm. In a single session, a physiatrist delivered a 3.5 cc solution of 2.5% lidocaine to the median nerve guided by ultrasound 58 days after implant.…”

“…Neuromodulatory interventions in human peripheral nerve have been explored using several different stimulation techniques. Transcutaneous electrical stimulation (TENS) and continuous kilohertz high‐frequency alternating current (KHFAC) stimulation both possess therapeutic benefits for chronic and acute pain, albeit with different mechanisms of action . TENS has been theorized toprovide analgesic benefits through central nervous system mechanisms, either though inhibitory gating of C‐fibers as proposed by Melzack and Wall , through descending inhibitory pathways, or a combination of both .…”

Peripheral Nerve Stimulation for Lower Extremity Pain

“…Similar settings are found in each of the studies listed in Table 2 . Less work is published in terms of high-frequency nerve stimulation for PNS; however, there are inklings that high-frequency stimulation will find a niche in the field of PNS [ 34 , 35 , 36 ].…”