We postulate that frequency-modulated electromagnetic stimulation (FREMS) may decrease pain in patients with painful diabetic neuropathy.

The stuy was designed as a randomized, double-blind, placebo-controlled cross-over trial. Each patient received two series of ten treatments of either FREMS or placebo in random sequence, with each series lasting no more than three weeks. Primary outcomes (daytime and night-time pain scores) an secondary outcomes (Motor and sensory nerve conduction velocity, sensory tactile perception, foot vibration perception threshold, quality of life, cutaneous microvascular flow, partial tissue tension of oxygen and carbon dioxide) were measured at baseline, after FREMS/placebo series and after 4 months follow-up.

Inclusion Criteria:

• type 1 or type 2 diabetes (American Diabetes Association criteria)
• painful diabetic neuropathy with reduced sensory/motor nerve conduction velocity (i.e., <40 m/sec in at least one nerve trunk of the lower limbs)
• vibration perception at the big toe >25 V

Exclusion Criteria:

• presence of any concomitant severe disease
• pregnancy
• renal disease (serum creatinine >2.0 mg/dL)
• history or current foot ulcer
• lower limb arterial disease (ankle-brachial index <0.9) or transcutaneous partial pressure of oxygen <50 mmHg)