CES would intuitively be useful in the treatment of headache, not only because it is stress reducing, a commonly accepted cause for many headaches, but because it stimulates across the theoretical pain message centers in the cortex of the brain. In the 1970s, a student completed his graduate thesis by studying 18 patients with migraine headaches. The study involved a treatment group, a sham treatment group and a placebo control group.  CES treatment was given 45 minutes a day for 15 days, Monday through Friday, and while the results were highly variable, a significant reduction in intensity and duration of headaches was found among the treated group.  There was no placebo effect from the treatment. Solomon and his group studied 112 patients with tension headaches.  To be in the study, patients had to have at least four headaches a week for a year, and these had to be so severe they required treatment with prescription medications.  The patients were asked to use CES for 20 minutes each time they had a headache, and if the pain did not go away, to use it for a second 20 minutes.  The study lasted for 10 weeks and the treated patients reported an average pain reduction of 35%, while the sham treated patients reported an 18% improvement.       Another study of migraine patients compared the effects of CES alone, biofeedback alone, or the two together.  The treatment lasted eight days and the patients were followed monthly for three months, in which they were asked to rate the number and intensity of headaches.  Both biofeedback and CES groups improved significantly more than the controls, and both groups continued to improve at each 30 day follow-up period, but it was found that CES potentiated the biofeedback gain by more than 70% by the third, 90 day period. Romano studied the ability of CES to reduce headaches in 100 fibromyalgia patients who were asked to use a CES device for four, 20 minute treatment periods each day for up to two months.  In this open clinical study the patients rated their improvement at 50% or greater in terms of reduced headache frequency and intensity. Forty-seven physicians who treated 151 headache patients with CES rated the treatment gain in 90% of them to be 25% or better. Patient warranty cards indicate that 118 patients who suffer from migraine headaches improved an average of 61%, while 112 who suffer from tension headaches improved 56%.  That improvement is somewhat lower than in the migraine group, possibly due to neuromuscular involvement in neck or shoulder muscles that did not receive stimulation from CES