THE ANALGESIC EFFECT OF PERCUTANEOUS ELECTRICAL NERVE STIMULATION (PENS) IN PATIENTS WITH CHRONIC HEADACHES

Abstract

S270 INTRODUCTION: Headache is one of the most common pain syndromes. [1] Although a large number of pharmacologic therapies have been used for the treatment of chronic headaches, most of these treatments are only partially effective and can produce unwanted side effects. This randomized, sham-controlled study was designed to evaluate a novel electroanalgesic technique known as percutaneous electrical nerve stimulation (PENS) for the short-term management of two common headache syndromes. METHODS: After obtaining IRB approval and written informed consent, 30 patients with either chronic tension-type or migraine headaches were treated with both PENS and sham-PENS according to a randomized, cross-over study design. The treatments consisted of 32 ga acupuncture-like needles placed into the soft tissue at the back of the neck and the scalp in a standardized montage corresponding to dermatomal levels C1 to C7. For the PENS therapy, electrical stimulation was applied through the needle probes while maintaining polarity with a current flow of <350 [micro sign]AMP and <1 mV at an alternating frequency of 15 Hz and 30 Hz with unipolar square-waves using a low-output (5 mAmp generator. No electrical stimulation was applied to the needle probes during the sham-PENS treatments. Assessments of the patients included visual analog scales (VAS) for pain, physical activity, and quality of sleep scores with (0=best to 10=worst). Pain assessment was performed immediately before and after each session. After receiving both treatment modalities, all patients completed a global assessment questionnaire comparing the effectiveness of the two therapies. RESULTS: Compared to the sham treatments, PENS therapy was significantly more effective in decreasing pain, as well as in improving the patient's physical activity and quality of sleep (* vs baseline {p<0.05} and [black diamond] vs sham-PENS {p<0.05}). Both types of headaches demonstrated identical responses to PENS therapy. On the global assessment questionnaire, there was a 56% decrease in pain scores after PENS therapy (vs 17 % with sham) in the tension-type headache group and a 60 % decrease after PENS therapy (vs 21% with sham) in the migraine headache group. (Table 1)Table 1DISCUSSION: PENS therapy has previously proved to be effective in the management of acute [2] and chronic [3] types of pain. In this study, PENS therapy appears to be a promising alternative to conventional analgesic medications for the short-term management of chronic headache.