Successful Treatment With Scrambler Therapy for Radial and Femoral Nerve Injuries After Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) is becoming increasingly widespread. The use of ECMO requires an arterial blood pressure monitoring catheter that can damage the radial1Kuo F. Park J. Chow K. Chen A. Walsworth M.K. Avoiding peripheral nerve injury in arterial interventions.Diagn Interv Radiol. 2019; 25: 380-391Crossref PubMed Scopus (2) Google Scholar or femoral nerve. A new complication of ECMO, severe femoral nerve neuropathy, has been reported.2Jang A.Y. Oh Y.J. Lee S.I. Lim O.K. Suh S.Y. Femoral neuropathy following venoarterial–extracorporeal membrane oxygenation therapy: a case report.BMC Cardiovasc Disord. 2020; 20: 393Crossref PubMed Scopus (1) Google Scholar That patient was still undergoing rehabilitation for persistent pain 200 days after ECMO. We recently saw a person with severe radial and femoral nerve neuropathy 2 months after ECMO and were able to relieve the pain in 2 days using scrambler therapy. The patient is a 26-year-old man with primary fibrolamellar hepatocellular carcinoma. He underwent debulking surgery of a large pelvic mass in August 2020, complicated by cardiovascular collapse requiring mechanical ventilation and ECMO. He required ECMO for 6 days, with an arterial line for 2 weeks. Two months after ECMO, he complained of burning pain associated with numbness and tingling in the right proximal wrist and thumb starting 1 inch distal to the arterial line scar. He had similar pain in the lateral and medial right calf corresponding to damage to L4 and L5. Both started about a week after his admission to the intensive care unit and became progressively worse. He rated the pain 8/10 (on a scale of 0-10) and 5 when he took oxycodone. He had marked muscle atrophy of the right thumb and calf. Electrode pairs were placed above the areas of pain on the forearm and above and below the areas of pain on the leg. The electrodes were placed on areas with normal sensation at least 2 cm from the borders of the neuropathic pain (Figure). His pain scores dropped to 0.5 (still a slight pain in the right first toe) and have remained that way for more than 2 months. He gave signed consent for his story and photographs to be used for publication. Johns Hopkins Investigational Review Board does not require approval for cases of 3 or fewer patients. Scrambler therapy is a relatively new neuromodulation technique3Kashyap K. Bhatnagar S. Evidence for the efficacy of scrambler therapy for cancer pain: a systematic review.Pain Physician. 2020; 23: 349-364PubMed Google Scholar that is useful in treatment of pain syndromes including chemotherapy-induced peripheral neuropathy,4Loprinzi C. Le-Rademacher J.G. Majithia N. et al.Scrambler therapy for chemotherapy neuropathy: a randomized phase II pilot trial.Support Care Cancer. 2020; 28: 1183-1197Crossref PubMed Scopus (13) Google Scholar other chronic pains (such as neuromyelitis optica spectrum disorder),5Mealy M.A. Kozachik S.L. Cook L.J. et al.Scrambler therapy improves pain in neuromyelitis optica: a randomized controlled trial.Neurology. 2020; 94: e1900-e1907Crossref PubMed Scopus (4) Google Scholar and central pain.6Christo P.J. Kamson D.O. Smith T.J. Treatment of Déjerine-Roussy syndrome pain with scrambler therapy.Pain Manag. 2020 May; 10: 141-145Crossref PubMed Google Scholar Scrambler therapy modulates the chronic pain signal by substituting “nonpain” information from 5 artificial neurons that capture surface receptors of the C nerve fibers.7Marineo G. Inside the scrambler therapy, a noninvasive treatment of chronic neuropathic and cancer pain: from the gate control theory to the active principle of information.Integr Cancer Ther. 2019; 18 (1534735419845143)Crossref PubMed Scopus (9) Google Scholar Pairs of electrocardiography electrodes are placed within the dermatome proximal to the area of pain and distal if possible, and the stimulus is adjusted to tolerance. The patient experiences a feeling akin to being bitten by electrical ants or even a light skin massage. There are now more than 60 scrambler therapy (or Calmare, 1 trade name) citations listed in PubMed, including successful randomized trials.4Loprinzi C. Le-Rademacher J.G. Majithia N. et al.Scrambler therapy for chemotherapy neuropathy: a randomized phase II pilot trial.Support Care Cancer. 2020; 28: 1183-1197Crossref PubMed Scopus (13) Google Scholar,5Mealy M.A. Kozachik S.L. Cook L.J. et al.Scrambler therapy improves pain in neuromyelitis optica: a randomized controlled trial.Neurology. 2020; 94: e1900-e1907Crossref PubMed Scopus (4) Google Scholar,8Marineo G. Iorno V. Gandini C. Moschini V. Smith T.J. Scrambler therapy may relieve chronic neuropathic pain more effectively than guideline-based drug management: results of a pilot, randomized, controlled trial.J Pain Symptom Manage. 2012; 43: 87-95Abstract Full Text Full Text PDF PubMed Scopus (65) Google Scholar,9Kashyap K. Singh V. Mishra S. Dwivedi S.N. Bhatnagar S. The efficacy of scrambler therapy for the management of head, neck and thoracic cancer pain: a randomized controlled trial.Pain Physician. 2020; 23: 495-506PubMed Google Scholar It is used extensively in the military with good success, especially with neuropathic pain and at experienced centers.10Moon J.Y. Kurihara C. Beckles J.P. Williams K.E. Jamison D.E. Cohen S.P. Predictive factors associated with success and failure for Calmare (scrambler) therapy: a multicenter analysis.Clin J Pain. 2015; 31: 750-756Crossref PubMed Scopus (13) Google Scholar As the use of ECMO expands, with requisite arterial lines near the neurovascular bundle, scrambler therapy or other forms of electroanalgesia, such as spinal cord stimulation, may hasten recovery.