Ear-nerve stimulator promising for chronic pain

By: Brunk, Doug

In 2005 Dr. Robert Bonakdar was searching through PubMed in preparation for a lecture he was about to deliver to physicians on the nonpharmacologic treatment of chronic pain.

He came across two randomized, controlled trials that described a disposable device that provides 1 Hz of continuous electrical stimulation to auricular acupuncture points as a treatment for chronic cervical pain and chronic lower back pain.

"They showed that these ear treatments helped after 4 weeks of treatment," recalled Dr. Bonakdar, director of pain management at the Scripps Center for Integrative Medicine in LaJolla, Calif. "I was intrigued."

He contacted the gadget's inventor, Dr. Josef C. Szeles, a vascular surgeon in Vienna, who traveled to San Diego and showed Dr. Bonakdar how to use the device, which is called Pulse Stimulation Treatment (previously known as IS-3 and P-STIM in Europe). Since then Dr. Bonakdar has treated scores of patients with Pulse Stimulation Treatment (PST) and has found it particularly effective for patients with shingles and other forms of neuropathic pain.

"There is a central sensitization phenomenon where the brain takes over and amplifies what would otherwise be a normal healing process and makes the pain worse," Dr. Bonakdar explained. "That happens mostly in neuropathic pain and quasineuropathic syndromes such as fibromyalgia, phantom limb pain, or complex regional pain syndrome. This is a way to give a benign signal to redirect the brain."

Approved by the Food and Drug Administration for acute and chronic pain in 2006, the PST is a battery-powered, controlled nerve stimulator that weighs about 7 g and is fastened behind the ear by an adhesive backing. Tiny titanium acupuncture needles are placed in three points of the outer ear that are considered to be indirect measures of nerve activity. Electrodes are then attached to the needles, which deliver 1 Hz of energy 3 hours at a time over the course of 4 days.

"From an acupuncture standpoint, 1 Hz is the universal endorphin releaser," said Dr. Bonakdar, who also performs traditional acupuncture and electrostimulation. "The patient feels a tapping for 3 hours; then PST goes off for 3 hours. From a neurological standpoint, this is really percutaneous auricular nerve stimulation, or PANS. The intriguing part is, there is nowhere else on the body besides the ear where I can so easily access the vagal nerve. I would need to open up your chest and go into the cardiac nerve bundles to access the vagal nerve, or I would need to put in a more invasive vagal nerve stimulator, as is done for refractory seizures. This is potentially an indirect way to do the same thing in a low-risk way."

Most patients need 4-6 treatments of 4 days' duration (each requiring one of the devices) to achieve good results, which Dr. Bonakdar defined as achieving 33%-50% reduction in their pain based on traditional pain scores such as the Brief Pain Inventory. In his clinical experience 60%-75% of patients achieve about a 50% reduction in their pain after 4-6 weeks of treatment.

Others, including a woman he previously treated for pain related to shingles, achieve near-immediate results. Before treatment she was taking 18 narcotic tablets per day for symptom relief. The day after PST, that dropped to just 4 tablets per day. "Over the next 4 weeks she went off the medicines completely," Dr. Bonakdar said. "With traditional acupuncture, you don't often get that immediate and strong effect. That's happened enough times to [make me think] we're hitting a direct circuit right from the vagal nerve to the brainstem with the PST." This case study was presented at a poster session at the 2006 annual meeting of the American Academy of Pain Management.

In mid-2008 Nu-Life Technologies acquired the distribution rights and license to the patents for the PST (www.pst4life.com). In an interview, Nu-Life's CEO Jim Robertson said that the device will be available to physicians in the United States in October 2008, but the company's initial focus is to offer it to existing pain clinics that already have a high base of patients. The business plan analogy he used was being "like a McDonald's inside of a Wal-Mart, where we put a fully turnkey package inside or attached to large pain centers." Mr. Robertson anticipates the cost of each PST to range from $350 to $425.

Dr. Bonakdar is a member of Nu-Life's medical advisory board. He receives no compensation for his role and has no financial interest in the company, but Nu-Life does supply him with PSTs to use in clinical practice.

Mr. Robertson said that Dr. Szeles is working with NuLife to develop the next-generation PST. "He's a member of our team in every way," he said.

BY DOUG BRUNK

San Diego Bureau