The comparative study of pain relief by TENS and analgesic drugs in primary dysmenorrhea

Abstract

Low frequency TENS is widely used for pain relief in Physical Therapy.  However, limited number of research was found regarding its effect on pain relief in primary dysmenorrhea. The purpose of this study was to compare the effect of pain relief in primary dysmenorrhea resulting from low frequency TENS and analgesic drugs. Fifteen healthy female Physical Therapy students, aged 18-22 years (mean 20.07+1.03 years) who always have dysmenorrheal pain with VAS score more than 8/10 participated in this study. They were randomly allocated to receive different sequence of the treatments within the first and second periods of dysmenorrhea, i.e. either taking a course of low frequency TENS and followed by usual analgesic drug or taking usual analgesic drug and followed by the TENS.  The TENS protocol included applying 30 minutes of stimulation with pain threshold intensity of 200 nm, 4 Hz, TENS in the first 24 hours of dysmenorrheal period. Four electrodes were placed on the skin 3 cm from midline at T12-L1 and S2-3 paravertebral muscles. The comparative group included normally used analgesic drug in the same period.  Dysmenorrheal pain, using the VAS scores, at before and each interval (0, 30, 60, 90, 150, 240 and 360 minutes) after each treatment were recorded. The results showed that VAS scores before and after in the TENS and drug protocols were 8.87±0.88, 3.33±1.45, 2.67±1.24, 2.60±1.06, 2.67±1.18, 3.13±1.36, 3.36±1.28 and 7.67±1.50 , 3.00±1.13, 2.67±1.23, 2.73±1.22, 2.8±1.37, 3.0±1.46, and 3.33±1.23 respectively. The VAS scores (within group) was significantly reduced at 30 minutes as compared to the those at 0 minute in both groups (p<0.001), whereas the between-group comparison was found with no significantly different. In addition, the VAS scores at 60, 90, 150, 240 and 360 minutes was no significantly different in either within group or between group comparison (p>0.05).  It is concluded that low frequency TENS may reduce primary dysmenorrheal pain as much as usual analgesic drug does.