***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Summary BACKGROUND : The aim of this study was to compare the efficacy and side effects of gabapentin , amitriptyline , and their combination in women with chronic pelvic pain . METHODS : In this open-label , prospect i ve , r and omized trial , 56 women with chronic pelvic pain were investigated with a two-year follow-up at the Vienna Medical University Hospital . If pain intensity assessed by a visual analog scale ( VAS ) was 5 or more ( 0 , no pain ; 10 , maximal pain ) , despite analgesic therapy using the nonopioid drug metamizol together with weak opioids , patients were r and omized to receive gabapentin ( n = 20 ) , amitriptyline ( n = 20 ) , or a combination of both drugs ( n = 16 ) . Doses of gabapentin and amitriptyline were increased to maximum daily doses of 3600 mg and 150 mg , respectively , until sufficient pain relief or the occurrence of side effects . VAS and side effects were evaluated before treatment and at 1 , 3 , 6 , 12 and 24 months afterwards . RESULTS : All patients experienced significant pain relief during the observation period . However , after 6 , 12 and 24 months , pain relief was significantly better in patients receiving gabapentin either alone or in combination with amitriptyline than in patients receiving monotherapy with amitriptyline ( gabapentin : 0 months , 7.7 ± 1.5 ; 6 months , 1.6 ± 0.9 ; 12 months , 1.5 ± 0.9 ; 24 months , 1.9 ± 0.9 ; amitriptyline : 0 months , 7.3 ± 1.5 ; 6 months , 2.2 ± 1.6 ; 12 months , 2.2 ± 1.6 ; 24 months ; 3.4 ± 0.9 ; amitriptyline-gabapentin : 0 months , 7.6 ± 0.8 ; 6 months , 1.3 ± 0.9 ; 12 months , 1.7 ± 1.0 ; 24 months , 2.3 ± 0.9 ) . Side effects were lower in the gabapentin group than in the two other groups , the difference reaching statistical significance after three months ( P < 0.05 ) . CONCLUSION : Gabapentin alone or in combination with amitriptyline is better than amitriptyline alone in the treatment of female chronic pelvic pain . ZusammenfassungEINLEITUNG : Gegenst and der Studie war der Vergleich der Wirksamkeit und Verträglichkeit von Gabapentin bzw . Amitriptylin allein mit der Kombination der beiden Medikamente bei chronischen Unterbauchschmerzen ( chronic pelvic pain , CPP ) . METHOD EN : 56 weibliche Patientinnen mit chronischen Unterbauschmerzen wurden bei der prospektiven , r and omisierten Open-label-Studie mit einem 2-jährigem Follow-up an der Schmerzambulanz der Universitätsklinik Wien , Österreich , eingeschlossen . Wenn die Schmerzintensität trotz analgetischer Therapie mit dem Nichtopioid Metamizol und einem schwachen Opioid gemessen auf der visuellen Analogskala ( VAS ) bei 5 oder darüber lag ( 0 , kein Schmerz ; 10 , schlimmster vorstellbarer Schmerz ) , wurden die Patientinnen r and omisiert einem der drei Beh and lungsarme zugeteilt ( Gabapentin , n = 20 ; Amitriptylin , n = 20 , oder beides , n = 16 ) . Die Medikamentengaben von Gabapentin bzw . Amitriptylin wurden auf eine tägliche Dosis von 3600 mg bzw . 150 mg gesteigert , bis eine suffiziente Schmerzerleichterung erreicht war oder unerwünschte Nebenwirkungen auftraten . VAS-Werte wurde vor Beginn der Beh and lung und 1 , 3 , 6 , 12 und 24 Monate danach erhoben . ERGEBNISSE : Alle Patientinnen erfuhren während des Beobachtungszeitraumes eine signifikante Schmerzreduktion . Dennoch war die Schmerzreduktion bei Patientinnen , die Gabapentin allein oder in Kombination mit Amitriptylin erhalten hatten , signifikant höher als unter Monotherapie mit Amitriptylin ( Gabapentin : 0 , 7,7 ± 1,5 ; 6 , 1,6 ± 0,9 ; 12 , 1,5 ± 0,9 ; 24 , 1,9 ± 0,9 ; Amitriptylin : 0 , 7,3 ± 1,5 ; 6 , 2,2 ± 1,6 ; 12 , 2,2 ± 1,6 ; 24 , 3,4 ± 0,9 ; Amitriptylin-Gabapentin : 0 , 7,6 ± 0,8 ; 6 , 1,3 ± 0,9 ; 12 , 1,7 ± 1,0 ; 24 , 2,3 ± 0,9 ) . Unerwünschte Nebenwirkungen traten signifikant seltener in der Gabapentin-Gruppe auf als in den beiden and eren Gruppen ( P < 0,05 ) . KONKLUSION : Diese Ergebnisse legen nahe , dass die Pharmakotherapie mit dem Antikonvulsivum Gabapentin die Beh and lung von chronischen Unterbauchschmerzen bei ambulanten Patientinnen verbessert OBJECTIVE To examine the prevalence of migraine in women with chronic pelvic pain with and without endometriosis . DESIGN Prospect i ve study of headache , pelvic pain , and quality of life before laparoscopic surgery for pelvic pain . Endometriosis was diagnosed pathologically . Headaches were classified as migraine or non-migraine using International Headache Society criteria . SETTING Clinical research hospital . PATIENT(S ) 108 women in a clinical trial for chronic pelvic pain ( NCT00001848 ) . INTERVENTION(S ) Laparoscopy to diagnose endometriosis , assessment by neurologist to assess headaches . MAIN OUTCOME MEASURE(S ) Prevalence of migraine and other headaches in women with chronic pelvic pain with or without endometriosis . Headache frequency , severity and relationship to pelvic pain and endometriosis . RESULT ( S ) Lifetime prevalence of definite or possible migraine was 67 % of women with chronic pelvic pain . An additional 8 % met criteria for possible migraine . Migraine was no more likely in women with endometriosis than those without . Women with the most severe headaches had a lower quality of life compared with those with pelvic pain alone . CONCLUSION ( S ) Migraine headache is common in women with chronic pelvic pain , regardless of endometriosis , and contributes to disability in those with both conditions . The strong association suggests a common pathophysiology Chronic  pelvic pain ( CPP ) in women is often debilitating and isolating . Problems with diagnosis continue to make CPP one of the most perplexing conditions in gynaecology , and one of the most difficult to treat BACKGROUND Chronic pelvic pain has often been described as a major women 's health issue , but no information exists on the extent of the problem in the United Kingdom . AIM To investigate the community prevalence of chronic pelvic pain and its effect on the lives of consulting and non-consulting women . DESIGN OF STUDY Postal question naire survey . SETTING Women aged 18 to 49 ( n = 3916 ) r and omly selected from the Oxfordshire Health Authority Register . METHOD The question naire response rate ( adjusted for non-deliveries ) was 74 % ( 2304/3106 ) . Chronic pelvic pain was defined as recurrent or constant pelvic pain of at least six months ' duration , unrelated to periods , intercourse , or pregnancy . Case subgroups comprised recent consulters , past consulters , and non-consulters . Women who reported dysmenorrhoea alone formed a comparison group . RESULTS The three-month prevalence of chronic pelvic pain was 24.0 % ( 95 % CI = 22.1 % to 25.8 % ) . One-third of women reported pain that started more than five years ago . Recent consulters ( 32 % of cases ) were most affected by their symptoms in terms of pain severity , use of health care , physical and mental health scores , sleep quality , and pain-related absence from work . Non-consulters ( 41 % of cases ) did not differ from women with dysmenorrhoea in terms of symptom-related impairment . Irrespective of consulting behaviour , a high rate of symptom-related anxiety was found in women with chronic pelvic pain ( 31 % ) compared with women with dysmenorrhoea ( 7 % ) . CONCLUSIONS This study showed a high community prevalence of chronic pelvic pain in women of reproductive age . Cases varied substantially in the degree to which they were affected by their symptoms . The high symptom-related anxiety in these women emphasises the need for more information about chronic pelvic pain and its possible causes Vulvar vestibulitis syndrome ( VVS ) is a common cause of dyspareunia in pre‐menopausal women . Recent evidence points to the importance of the sensory component in VVS , particularly the heightened processing of tactile and pain sensation in the vulvar vestibule . The goal of the present study was to examine the neural basis of heightened sensitivity to touch ( i.e. allodynia ) in women with VVS . Using functional magnetic resonance imaging , we compared regions of neural activity in 14 women with VVS and 14 age‐ and contraceptive‐matched control women  in response to the application of mild and moderate pressure  to the posterior portion of the vulvar vestibule .  Intensity and unpleasantness ratings were recorded after each scan ; these ratings were significantly higher for women with VVS than controls . All women with VVS described moderate pressure as painful and unpleasant , and 6 of the 14 women with VVS described mild pressure as painful and unpleasant . In contrast , none of the stimuli was painful for control women . Correspondingly , women with VVS showed more significant activations during pressure levels that they found to be either painful or non‐painful than did controls during comparable pressure levels . During pressure described as painful by women with VVS , they had significantly higher activation levels in the insular and frontal cortical regions than did control women . These results suggest that women with VVS exhibit an augmentation of genital sensory processing , which is similar to that observed for a variety of syndromes causing hypersensitivity , including fibromyalgia , idiopathic back pain , irritable bowel syndrome , and neuropathic pain Abstract Pain symptoms of many disorders are reported to vary with menstrual stage . This study investigated how pain thresholds to electrical stimulation of the skin , subcutis and muscle tissue varied with menstrual stage in normal women and compared these variations with those in women with dysmenorrhea and in healthy men at matched intervals . Thresholds of the three tissues were measured four times during the course of one menstrual cycle at four sites . Two of the sites were on the abdomen within the uterine viscerotome ( abdomen‐rectus abdominis , left and right ) and two were outside it on the limbs ( leg‐quadriceps , arm‐deltoid ) . Calculated from the beginning of menstruation ( day 0 ) , the menstrual phases studied were menstrual ( days 2–6 ) , periovulatory ( days 12–16 ) , luteal ( days 17–22 ) and premenstrual ( days 25–28 ) . Spontaneous pain associated with menstruation was measured from diary estimates on a VAS scale . Menstrual phase , dysmenorrhea and tissue : Whereas the highest thresholds always occurred in the luteal phase regardless of segmental site or stimulus depth , the lowest thresholds occurred in the periovulatory stage for skin , whereas those for muscle/subcutis occurred perimenstrually . Dysmenorrhea accentuated the impact of menstrual phase . For non‐dysmenorrheic women menstrual trends were significant only in abdominal muscle and subcutis , but for dysmenorrheic women the trends were also significant in abdominal skin and in limb muscle and subcutis . Dysmenorrhea also lowered thresholds mainly in muscle and sometimes in subcutis , but never in skin , with the greatest hyperalgesic effects in left abdominis muscle . Segmental site : Abdominal sites were more vulnerable to menstrual influences than limb sites . Muscle thresholds , but not skin or subcutis thresholds , were significantly lower in abdomen than in limbs , particularly in dysmenorrheic women .  The amount of abdominal muscle hyperalgesia correlated significantly with the amount of spontaneous menstrual pain . Sex differences : Only minor sex differences were observed for pain thresholds of the arm and leg , but there was a unanimous refusal by men , but not by women , to be tested at abdominal sites . These results indicate that menstrual phase , dysmenorrhea status , segmental site , tissue depth and sex all have unique interacting effects on pain thresholds , thus adding more items to the lengthy and still‐growing list of biological factors that enter into an individual 's judgment of whether or not a stimulus is painful Introduction Chronic pelvic pain ( CPP ) affects > 1 million UK women . Annual healthcare costs are estimated at > £ 150 million . Proven interventions for CPP are limited , and treatment is often unsatisfactory . Gabapentin is increasingly prescribed due to reports of effectiveness in other chronic pain conditions , but there are insufficient data supporting value in CPP specifically . The mechanism by which gabapentin exerts its analgesic action is unknown . Given the prevalence and costs of CPP , the authors believe that a large , 
    Output:
    
RESULTS CPP is associated with central changes similar to those identified in other pain conditions .
Specifically these include , alterations in the behavioural and central response to noxious stimulation , changes in brain structure ( both increases and decreases in the volume of specific brain regions ) , altered activity of both the hypothalamic-pituitary-adrenal axis and the autonomic nervous system ( ANS ) and psychological distress .
CONCLUSIONS The evidence review ed in this paper demonstrates that CPP is associated with significant central changes when compared with healthy pain-free women .
Moreover , the presence of these changes has the potential to both exacerbate symptoms and to predispose these women to the development of additional chronic conditions .