High-definition transcranial direct current stimulation was well tolerated and produced a significant reduction in overall perceived pain in patients with fibromyalgia, according to recent study results.
In a double blind phase 1 trial, researchers at Harvard Medical School studied 18 patients (mean age, 50.3 years; 83.3% women) with fibromyalgia (mean time since diagnosis, 10.7 years), and examined the effects of transcranial direct current stimulation (tDCS) using a 4x1 ring configuration of high definition-tDCS (HD-tDCS; Soterix Medical). Patients were randomly assigned to undergo single 20-minute sessions of anodal, cathodal and sham HD-tDCS at 2 mA. A center electrode was placed over the left primary motor cortex. Before and after each intervention, pain scales and sensory testing were assessed. A generated finite element method brain model predicted electric field distribution.
Compared with sham stimulation, both active stimulations led to significant reduction in perceived pain. For cathodal HD-tDCS, the effect occurred immediately and for anodal and cathodal HD-tDCS, 30 minutes after stimulation. The interventions were well tolerated by the patients.
“The technique may have other applications in research and clinical settings, which should be further explored,” the researchers concluded.
“HD-tDCS is a ‘platform technology’ and currently we are looking at multiple indications — stroke, pain, epilepsy … ,” Abhishek Datta, PhD, chief technology officer of Soterix Medical and co-inventor of HD-tDCS, told Healio.com. “The phase 2 trial is about to begin, which will answer more questions. For example, the phase 1 study was just ‘one session’ of HD-tDCS. In phase 2, we are exploring repetitive sessions — 1 day per week. We need to find the right trial parameters (current intensity, duration, how many sessions) before we can plan a pivotal FDA trial.”