chronic pelvic pain may involve organ system diagnosis including gynecological pain , interstitial cystitis or painful bladder syndrome , irritable bowel syndrome , vulvodynia , pelvic floor tension myalgia , and abdominal and pelvic myofascial pain . in our study , patients with chronic pelvic pain due to benign lesions of genital tract , gastrointestinal , and renal disorders were excluded from the study after performing an ultrasound study of abdomen and pelvis .
the pathophysiology of idiopathic chronic pelvic pain in the absence of organic lesions is usually obscured .
it affects 2% of women at the peak of their career , affecting their social life and confidence levels .
the first - line therapy according to the international guidelines is analgesics and anti - inflammatory medicines .
unfortunately , most patients are middle to old age and do not tolerate gastric side effects such as gastritis , nausea , and vomiting .
the care of elderly and middle age should be our prime concern in this era of rising life expectancy .
hence , this study was designed to assess the effectiveness and safety of transcutaneous electrical nerve stimulation ( tens ) in chronic pelvic pain .
ancient egyptians ( 1200 bc ) and romans ( 46 ad ) have used fishes to deliver electric current therapy for various ailments .
tens is based on the gate control theory of abolishing the local pain reflex arc .
tens triggers the hypothetical gate located in the lamina v of dorsal horn ganglia of the spinal cord to close .
this is achieved by providing simultaneous inputs from the t10 dermatome located in the suprapubic area .
it is a nonpharmacological and physiological method of inhibiting the presynaptic afferent neurons carrying impulses from pelvis by stimulating the nerves of peripheral segmental dermatome ( gate control theory of electromodulation by stimulating the peripheral nerves corresponding to the visceral organ ) .
it has also been hypothesized that the tens works by improving the local vascularity and a possible inhibition of sympathetic impulses by the release of brain endorphins .
this prospective study was conducted in the department of obstetrics and gynecology and department of physiotherapy at saveetha medical college , chennai , from january 2015 to january 2016 .
inclusion criteria were women with chronic pelvic pain not responding to analgesic and anti - inflammatory therapy in the age group of 1860 years .
patients with known abdominal or pelvic pathology , pregnancy , or any medication for chronic renal diseases were excluded from the study .
clinical history of pelvic inflammatory disease ( pid ) and prolapse was taken in all cases .
pap smear and clinical pelvic bimanual examinations were done for all cases to rule out pid .
ninety two patients with a clinical diagnosis of chronic pelvic pain were treated with square wave biphasic pulse of frequency < 25 hz ( g1 ) , 2575 hz ( g2 ) , and 75100 hz ( g3 ) with a current density on two electrodes , each 4 cm .
the number of patients is g0 = 30 , g1 = 30 , g2 = 32 , and g3 = 30 .
the controls taken were matched with cases with regards to age , duration of pain , and severity of pain .
the three parameters of current were adjusted . a = amplitude , f = frequency , and d = duration [ figure 1 ] .
further , there are options such as burst current , continuous current , and amplitude modulated current .
cases and controls were comparable in terms of pre - tens pain scores and maximum intensity tolerated by the patient was used .
the principle is the balance between receptor downregulation with increasing frequency and minimal effective frequency .
three different frequencies were used the electrodes were applied on suprapubic dermatome corresponding to t10 after explaining the procedure . the current amplitude was gradually increased and set at the maximum tolerated by the patient ( 080 ma ) .
the electrode - skin impedance was minimized by applying a generous layer of electrode gel to promote good contact under entire electrode .
ten treatment sessions ( five sessions / week ) of 30 min were conducted for each patient .
thirty cases of chronic pelvic pain were taken as controls on placebo ( g0 ) .
for ensuring the blinding of participants , tens electrodes were attached to the control group as in the study group but no current was delivered .
statistical analysis was done using student 's paired t - test and analysis of variance test using spss ( spss for windows v16 , wa , usa ) package .
the mean age of the 122 patients was 48 years ( range : 1860 ) .
cases were comparable to controls in age , duration , and intensity of pain scores .
tens showed an improvement in the low - frequency group ( g1 = 30 ) . in the low - frequency group , there was a reduction in the pain score from pretest scores ( 6.77  2.21 ) to ( 2.07  1.05 ) in the post - tens group .
this was statistically significant reduction ( p = 0.0001 , t = 10.05 , standard error of deviation ( sed ) = 1.73 ) [ table 1 ] .
placebo group ( g0=30 ) and transcutaneous electrical nerve stimulation ( g1=30 , g2=32 , and g3=30 ) group : pretest and posttest scores in the tens treatment group with medium frequency ( g2 = 32 ) , there was a reduction in the pain scores from pretest scores ( 6.66  2.34 ) to ( 2.38  1.10 ) in the post - tens group .
this was a statistically significant reduction ( p = 0.0001 , t = 9.38 , sed = 1.83 ) [ table 1 ] .
in the tens treatment group with high frequency ( g3 = 30 ) , the reduction in the pain from pretest scores ( 7.03  2.20 ) to ( 1.67  0.802 ) in the post - tens group .
this was a statistically significant reduction ( p = 0.0001 , t = 12.5 , sed = 1.66 ) [ table 1 ] . in placebo control group
( g0 = 30 ) , there was no reduction in pain from pretest scores ( 5.53  1.53 ) to ( 4.83  1.42 ) in the posttest scores .
this was not statistically significant reduction ( p = 0.071 , t = 1.84 , sed = 1.47 ) .
thus , there was a significant reduction ( mean  sd ) in pain scores in all the tens group but not in placebo group .
box plot for all the frequencies showed the maximum significant reduction in the high - frequency group [ figure 2 ] .
improvement in pain scores in placebo ( g0 = 30 ) , low frequency ( g1 = 30 ) , medium frequency ( g2 = 32 ) , and high frequency ( g3 = 30 )
this prospective study was conducted in the department of obstetrics and gynecology and department of physiotherapy at saveetha medical college , chennai , from january 2015 to january 2016 .
inclusion criteria were women with chronic pelvic pain not responding to analgesic and anti - inflammatory therapy in the age group of 1860 years .
patients with known abdominal or pelvic pathology , pregnancy , or any medication for chronic renal diseases were excluded from the study .
clinical history of pelvic inflammatory disease ( pid ) and prolapse was taken in all cases .
pap smear and clinical pelvic bimanual examinations were done for all cases to rule out pid .
ninety two patients with a clinical diagnosis of chronic pelvic pain were treated with square wave biphasic pulse of frequency < 25 hz ( g1 ) , 2575 hz ( g2 ) , and 75100 hz ( g3 ) with a current density on two electrodes , each 4 cm .
the number of patients is g0 = 30 , g1 = 30 , g2 = 32 , and g3 = 30 .
the controls taken were matched with cases with regards to age , duration of pain , and severity of pain .
the three parameters of current were adjusted . a = amplitude , f = frequency , and d = duration [ figure 1 ] .
further , there are options such as burst current , continuous current , and amplitude modulated current .
cases and controls were comparable in terms of pre - tens pain scores and maximum intensity tolerated by the patient was used .
the principle is the balance between receptor downregulation with increasing frequency and minimal effective frequency .
three different frequencies were used the electrodes were applied on suprapubic dermatome corresponding to t10 after explaining the procedure . the current amplitude was gradually increased and set at the maximum tolerated by the patient ( 080 ma ) .
the electrode - skin impedance was minimized by applying a generous layer of electrode gel to promote good contact under entire electrode .
ten treatment sessions ( five sessions / week ) of 30 min were conducted for each patient .
thirty cases of chronic pelvic pain were taken as controls on placebo ( g0 ) .
for ensuring the blinding of participants , tens electrodes were attached to the control group as in the study group but no current was delivered .
statistical analysis was done using student 's paired t - test and analysis of variance test using spss ( spss for windows v16 , wa , usa ) package .
the mean age of the 122 patients was 48 years ( range : 1860 ) . cases were comparable to controls in age , duration , and intensity of pain scores .
tens showed an improvement in the low - frequency group ( g1 = 30 ) . in the low - frequency group
, there was a reduction in the pain score from pretest scores ( 6.77  2.21 ) to ( 2.07  1.05 ) in the post - tens group .
this was statistically significant reduction ( p = 0.0001 , t = 10.05 , standard error of deviation ( sed ) = 1.73 ) [ table 1 ] .
placebo group ( g0=30 ) and transcutaneous electrical nerve stimulation ( g1=30 , g2=32 , and g3=30 ) group : pretest and posttest scores in the tens treatment group with medium frequency ( g2 = 32 ) , there was a reduction in the pain scores from pretest scores ( 6.66  2.34 ) to ( 2.38  1.10 ) in the post - tens group .
this was a statistically significant reduction ( p = 0.0001 , t = 9.38 , sed = 1.83 ) [ table 1 ] . in the tens treatment group with high frequency ( g3 = 30 ) , the reduction in the pain from pretest scores ( 7.03  2.20 ) to ( 1.67  0.802 ) in the post - tens group .
this was a statistically significant reduction ( p = 0.0001 , t = 12.5 , sed = 1.66 ) [ table 1 ] . in placebo control group (
g0 = 30 ) , there was no reduction in pain from pretest scores ( 5.53  1.53 ) to ( 4.83  1.42 ) in the posttest scores .
this was not statistically significant reduction ( p = 0.071 , t = 1.84 , sed = 1.47 ) .
thus , there was a significant reduction ( mean  sd ) in pain scores in all the tens group but not in placebo group .
box plot for all the frequencies showed the maximum significant reduction in the high - frequency group [ figure 2 ] .
improvement in pain scores in placebo ( g0 = 30 ) , low frequency ( g1 = 30 ) , medium frequency ( g2 = 32 ) , and high frequency ( g3 = 30 )
there was a significant improvement in pain scores in tens group , and two patients were completely pain free following tens therapy .
our study had the maximum pain relief in the high - frequency tens group , thereby showing a dose - response relationship of tens in the treatment of chronic pelvic pain .
high - intensity tens ( 75100 hz ) with maximum tolerability is shown to have maximum effect .
lifestyle modifications and analgesics have been practiced earlier . in our study , we found a significant improvement in symptoms after tens as the first - line treatment .
this is in accord with other studies where tens has been compared with anti - inflammatory therapy and sacral neuromodulation therapy .
several prospective studies have implicated tens as an effective and safe treatment warranting randomized , placebo , controlled trials . in elderly patients where other comedications have their own gastrointestinal side effects and impairment of cognition is a concern , tens can be a useful intervention .
genetic differences result in dissimilar metabolic degradation of nonsteroidal anti - inflammatory drugs by cytochrome p 450 , so dose adjustment is a challenge .
limitation of our study is that patients who are involved in the clinical trial received more intensive monitoring of their treatment .
this might explain the improvement in pain scores in our set of patients who were taken as controls .
efficacy of tens depends on the accepted principle that an optimal effect requires an adequate dose .
steps taken to prevent tolerance to tens therapy include the use of alternate high and low frequencies and using burst currents .
the initial accumulation and then gradual reduction of endogenous opioids vary widely among individuals . on an average ,
the effect of tens lasts for 1824 h. tens units are commercially available without prescription as over counter or rom internet .
indian physiotherapists use tens predominantly for musculoskeletal pain and neuropathic pain and rarely for dysmenorrhea , labor pain , and postoperative pain .
tens devises may be loaned to the patients for their duration of stay during hospital .
similar to the model of patient controlled analgesia , patient can be trained on how to self - administer tens .
costs to the clinic will be initial outlay for tens devise and then the running costs of replacing batteries and self - adhering electrodes or carbon rubber electrodes . in rural india
, there may be a sociocultural barrier to accept tens due to reluctance to try new treatments .
carbon electrodes will be a better choice in rural india as self - adhering electrodes deteriorate rapidly if not kept in cool and dust - free area .
tens is a portable , nonaddictive , and noninvasive means of pain relief with flexible patient directed dosing .
small electrical pulses delivered through electrodes directly placed on skin reduce pain scores through both central and peripheral mechanisms .
high stimulus just below strong but comfortable intensity with alternating high- and low - frequency current produces maximal effect .
there is increasing evidence that the therapy is also effective in labor pain , overactive bladder , vulvodynia , fecal incontinence and neurogenic dysfunctional elimination syndrome , and poststroke incontinence .
future advancements will likely emphasis on the exact placement site of electrodes with less collateral stimulation .
 background : chronic pelvic pain is prevalent in 2% of women population globally . 
 the etiology is multifactorial . even in the absence of pelvic pathology 
 , there is a subgroup of women who do not respond to analgesic and anti - inflammatory therapy . 
 chronic pelvic pain can be inhibited by direct inhibition of impulses in the preganglionic afferent neuron by closing the hypothetical gate in the dorsal horn of the spinal cord . 
 transcutaneous electrical nerve stimulation ( tens ) is based on the gate control theory of abolishing the painful stimuli by providing simultaneous inputs in larger myelinated nerve fibers.aims and objectives : this study was designed to assess the effectiveness and safety of tens in idiopathic chronic pelvic pain.methods:it is a prospective , experimental study to evaluate the effectiveness of tens versus placebo in reducing pain severity in chronic pelvic pain ( g1 = 30 , g2 = 32 , g3 = 30 , and g0 = 30 ) . 
 patients with chronic pelvic pain due to benign lesions of genital tract , gastrointestinal , and renal disorders were excluded from the study after performing an ultrasound study of abdomen and pelvis . 
 ten treatment sessions ( 5 sessions / week ) of 30 min were conducted.observations and results : there was a significant improvement in pain scores in tens group as compared with control group , and two patients were completely pain free following tens therapy.conclusion:in women patients with idiopathic chronic pelvic pain , tens can be a useful intervention . 
 tens units are safe , economical , and easily commercially available . 
INTRODUCTION
METHODS
Study design
Observations
RESULTS
DISCUSSION
CONCLUSION
Financial support and sponsorship
Conflicts of interest