Pulsed electromagnetic fields to reduce diabetic neuropathic pain and stimulate neuronal repair: a randomized controlled trial.
OBJECTIVE
To determine whether repetitive and cumulative exposure to low-frequency pulsed electromagnetic fields (PEMF) targeting painful feet can reduce neuropathic pain (NP), influence sleep in symptomatic diabetic peripheral neuropathy (DPN), and influence nerve regeneration.


METHODS
Randomized, double-blind, placebo-controlled parallel study.


METHODS
Sixteen academic and clinical sites in 13 states.


METHODS
Subjects (N=225) with DPN stage II or III were randomly assigned to use identical devices generating PEMF or sham (placebo) 2 h/d to feet for 3 months.


METHODS
Nerve conduction testing was performed serially.


METHODS
Pain reduction scores using a visual analog scale (VAS), the Neuropathy Pain Scale (NPS), and the Patient's Global Impression of Change (PGIC). A subset of subjects underwent serial 3-mm punch skin biopsies from 3 standard lower limb sites for epidermal nerve fiber density (ENFD) quantification.


RESULTS
Subjects (N=225) were randomized with a dropout rate of 13.8%. There was a trend toward reductions in DPN symptoms on the PGIC, favoring the PEMF group (44% vs 31%; P=.04). There were no significant differences between PEMF and sham groups in the NP intensity on NPS or VAS. Twenty-seven subjects completed serial biopsies. Twenty-nine percent of PEMF subjects had an increase in distal leg ENFD of at least 0.5 SDs, while none did in the sham group (P=.04). Increases in distal thigh ENFD were significantly correlated with decreases in pain scores.


CONCLUSIONS
PEMF at this dosimetry was noneffective in reducing NP. However neurobiological effects on ENFD, PGIC and reduced itching scores suggest future studies are indicated with higher dosimetry (3000-5000 G), longer duration of exposure, and larger biopsy cohort.
Weintraub
Michael I
MI
Department of Neurology, New York Medical College, Valhalla, NY, USA. miwneuro@pol.net
Herrmann
David N
DN
Smith
A Gordon
AG
Backonja
Misha M
MM
Cole
Steven P
SP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003929:Diabetic Neuropathies / Q000150:complications / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D004311:Double-Blind Method; D005260:Female; D005528:Foot; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology; D009431:Neural Conduction; D009474:Neurons / Q000473:pathology*; D010146:Pain / Q000209:etiology; D059408:Pain Management; D012867:Skin / Q000294:innervation / Q000503:physiopathology; D050781:Transcranial Magnetic Stimulation