human
***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: Study Design . This was a prospect i ve observational study of patients with low back pain and those without after laminotomy and discectomy .  Objectives . To determine , using a strict experimental design , the relative pain intensity response to provocative discography in symptomatic and asymptomatic subjects after lumbar discectomy for intervertebral disc herniation . Background . Provocative discography frequently is used to evaluate persistent or recurrent low back pain syndromes in patients who have undergone posterior discectomy . The validity of interpreting painful injections during this procedure has not been critically assessed . The prevalence of significantly painful disc injections in a group with good outcomes after surgery is not known . Knowing the rates of significantly painful injections in asymptomatic patients after lumbar discectomy may clarify the meaning of painful injections in symptomatic patients . Methods . From a cohort of 240 patients who had undergone single-level limited discectomy for sciatica , 20 asymptomatic volunteers were recruited for experimental three-level lumbar discography . Inclusion criteria required nearly perfect scores on st and ardized back pain rating instruments , no other spinal pathology , and normal psychometric screening . A control group of 27 symptomatic patients , after single-level discectomy with intractable low back pain syndrome , and without other spinal pathology , underwent discography . Seven patients in the control group had normal psychometric tests . Experienced raters who were blinded to control versus experimental status of the subjects scored the magnetic resonance imaging , discogram , psychometric tests , and discography videotapes of the subjects ’ pain behavior . Results . There were 8 of 20 ( 40 % ) positive injections of discs that had previous surgery in the asymptomatic group and 17 of 27 ( 63 % ) positive injections in the symptomatic group . Specifically with regard to the symptomatic group , there were 3 of 7 ( 43 % ) positive injections ( all concordant ) in patients with normal psychometric scores , as compared with 14 of 20 ( 70 % ) positive injections ( 12 concordant ) in patients with abnormal psychometric scores . Injections of discs that had previous surgery result ed in a mean pain score of 2.1 of 5 in the asymptomatic group , 2.1 in the symptomatic group with normal psychometric scores , and 3.4 in the symptomatic group with abnormal psychometric scores . Of the discs not treated with surgery , 2 were positive in the asymptomatic group ( 10 % ) , 3 in 2 symptomatic subjects with normal psychological testing ( 29 ) , and 18 in 13 symptomatic subjects with abnormal psychometric testing ( 76 % ) . Conclusions . A high percentage of asymptomatic patients with normal psychometric testing who previously have undergone lumbar discectomy will have significant pain on injection of their discs that had previous surgery ( 40 % ) . This is not significantly different from the experience of symptomatic patients with normal psychometric testing undergoing discography on discs that had previous surgery . Patients with abnormal psychological profiles have significantly higher rates of positive disc injections than either asymptomatic volunteers or symptomatic subjects with normal psychological screening BACKGROUND Patients with chronic low back pain present physicians with diagnostic and therapeutic problems . Physical treatments tend to have low success rates and it is postulated that this may be because low back pain can be a manifestation of abnormal illness behaviour . METHODS A structured prospect i ve study determined the prevalence of somatization in a sample of 131 adult patients with chronic low back pain using the Illness Behaviour Question naire ( IBQ ) and the Modified Somatic Perception Question naire ( MSPQ ) . The scores on these psychological question naires were compared with the blind interpretation of pain distribution drawings and with the results of a mechanical classification of the patient 's symptoms and signs . RESULTS Fifty-four per cent of patients had four or more ( out of five ) abnormal illness indicators . The MSPQ values for the group were significantly above the control values in the literature . Thirty-two per cent of pain diagrams were thought to be incompatible with an organic cause when assessed by an orthopaedic surgeon and sixty-two per cent when assessed by a psychiatrist . CONCLUSIONS Psychosocial factors are dominant in the presentation of chronic low back pain in adults and the disorder is not primarily a musculoskeletal one An attempt was made to determine the relative contribution of various structures to chronic low back pain , including facet joint(s ) , disc(s ) , and sacroiliac joint(s ) in a prospect i ve evaluation . Precision diagnostic blocks , including disc injections , facet joint blocks , and sacroiliac joint injections , are frequently used . In contrast , selective nerve root blocks or transforaminal epidural injections are used occasionally to evaluate persistent or recurrent low back pain in patients without appropriate radiologic or neurophysiologic diagnosis . One hundred and twenty patients with a chief complaint of low back pain were evaluated with precision diagnostic injections , which included medial branch blocks , provocative discography and sacroiliac joint injections . In 40 % ( 95 % CL , 31 % , 49 % ) , of the patients , facet joint pain was diagnosed ; and in 26 % ( 95 % CL , 18 % , 34 % ) of the patients discogenic pain was diagnosed ; and 2 % of the patients were diagnosed with sacroiliac joint pain OBJECTIVE To evaluate the prevalence of facet joint pain in patients with chronic low back pain ( CLBP ) after surgical intervention(s ) . DESIGN A prospect i ve , nonr and omized , consecutive study . SETTING An ambulatory interventional pain management setting . PARTICIPANTS The prevalence of facet joint pain was evaluated in patients with CLBP after various surgical intervention(s ) referred to an interventional pain management practice . The sample was derived from 282 patients with persistent CLBP after various surgical intervention(s ) . Of these , 242 patients consented to undergo interventional techniques .  A total of 117 consecutive patients with chronic , nonspecific low back pain , after lumbar surgical intervention(s ) were evaluated with controlled , comparative local anesthetic blocks . INTERVENTIONS Controlled , comparative local anesthetic blocks ( 1 % lidocaine or 1 % lidocaine followed by .25 % bupivacaine ) under fluoroscopic visualization using 0.5mL to block each facet joint nerve . MAIN OUTCOME MEASURES A positive response was defined as at least 80 % reduction of pain with ability to perform previously painful movements . A positive response was considered to be pain relief from the lidocaine block lasting at least 1 hour or at least 2 hours or greater than duration of relief with lidocaine when bupivacaine was used . Controlled , comparative local anesthetic blocks were used to eliminate false-positive results . Valid information is only obtained by performing controlled blocks in the form of comparative local anesthetic blocks , in which , on 2 separate occasions , the same joint is anesthetized by using local anesthetics with different duration s of action . If patients obtained appropriate response with both blocks , they were considered a positive . If they obtained appropriate response with lidocaine but not with bupivacaine , they were considered false-positive , whereas if the response was negative with lidocaine , they were considered negative . RESULTS The prevalence of lumbar facet joint pain in patients with recurrent pain after various surgical intervention(s ) was 16 % ( 95 % confidence interval , 9%-23 % ) . The false-positive rate with a single block with lidocaine was 49 % . CONCLUSIONS Facet joints are clinical ly important pain generators in a small but significant proportion of patients with recurrent CLBP after various surgical intervention(s ) BACKGROUND Psychological disorders may be associated with poor pain related treatment outcomes . However , there may be limitations with studies evaluating the relationship between pain and psychopathology . OBJECTIVE To assess the reliability of  psychological evaluations  in interventional pain management by MCMI-III(R ) and P-3(R ) . STUDY DESIGN Prospect i ve evaluation of consecutive patients in an interventional pain management center . METHODS Patients were evaluated using a DSM-IV-TR(R ) question naire with a physician interview as an integral part of their comprehensive evaluation . In addition , all the patients participating in this study also underwent psychological evaluation with MCMI-III and P-3 . A positive diagnosis of major depression or generalized anxiety disorder based on DSM-IV-TR criteria was considered as the criterion st and ard . All of the patients presented for treatment of chronic pain . The data based on the criterion st and ard were compared with results of the diagnostic impression from the MCMI-III and the P-3 evaluation utilizing criteria for average , and above average , patient pain scores . RESULTS Major depression was diagnosed in a total of 59 of 100 patients using DSM-IV-TR criteria , in 32 patients based on MCMI-III criteria , and in 55 patients based on P-3 evaluations utilizing average pain patient criteria . Generalized anxiety disorder was diagnosed in 55 patients by means of DSM-IV-TR , 45 patients by MCMI-III , and 55 patients by P-3 Profile utilizing average pain patient scores . The specificity of MCMI-III was 100 % with a sensitivity of 54 % for diagnosis of depression ; whereas it was 78 % specificity and sensitivity for P-3 , with average pain patient scores . For generalized anxiety disorder , specificity of MCMI-III was 89 % with a sensitivity of 73 % compared to specificity of 80 % and sensitivity of 84 % for average pain patient scores for P-3 . CONCLUSION MCMI-III and P-3 are highly specific in diagnosing depression and generalized anxiety disorder , with variable sensitivity . A DSM-IV-TR question naire evaluation incorporated into the pain management question naire , along with a short clinical interview , is a reliable means of assessing depression and anxiety in patients suffering with chronic pain Study Design . A prospect i ve cross-sectional analytic approach was taken . Objectives . This study sought to determine the relative contribution of the disc and the zygapophyseal Joint as a pain source in patients with chronic low back pain . Summary of Background Data . Previous studies have employed either zygapophyseal joint blocks or discography , but in no studies have both procedures been performed . Methods . Ninety-two consecutive patients with chronic low back pain were studied using both discography and blocks of the zygapophyseal joints . Results . Thirty-six patients ( 39 % ) had at least one positive discogram as defined by exact pain reproduction , an abnormal image , and a negative control . Eight patients responded to both a screening zygapophyseal joint block using lignocaine and confimatory block using bupivacaine . Only three patients had both a positive discogram and a symptomatic zygapophyseal joint . Conclusions . In patients with chronic low back pain , the combination of discogenic pain and zygapophyseal joint pain is uncommon BACKGROUND Lumbar facet ( zygapophysial ) joints have been implicated as the source of chronic pain in 15 % to 45 % of patients with chronic low back pain . Diagnosis may be confounded by false-positive results with a single diagnostic block and administration of anxiolytics and narcotics prior to or during the diagnostic facet joint blocks . OBJECTIVE To evaluate the effect of midazolam and fentanyl on the diagnostic validity of of lumbar facet joint pain . STUDY DESIGN R and omized , prospect i ve , double-blind , placebo-controlled evaluation . METHODS The design consisted of a placebo group receiving sodium chloride solution and two experimental groups receiving either midazolam or fentanyl . The patients included in the study were diagnosed with facet joint pain with controlled comparative local anesthetic blocks of medial branches or L5 dorsal rami . They had been treated with lumbar facet joint nerve blocks with good pain relief , and were presenting for repeat treatment after a period of symptom relief . The study was undertaken in an interventional pain management practice . OUTCOME MEASURES Outcomes were assessed at baseline and after the administration of 1 of the 3 solutions ( Group I , sodium chloride solution ; Group II , midazolam ; or Group III , fentanyl ) . Outcome measures included numeric pain scale , proportion of pain relief , and ability to perform prior painful movements . RESULTS Pain relief of > or = 80 % was noted in 2 % of the patients in Group I , 5 % of the patients in Group II , and 7 % in Group III . Pain relief of > or = 50 % was noted in 7 % of the patients in Group I , 5 % of the patients in Group II , and 13 % of the patients in Group III . There were no significant differences among the groups . CONCLUSION The administration of sedation with midazolam or fentanyl is a confounding factor in the diagnosis of lumbar facet joint pain in patients with chronic low back pain . However , this study suggests that if strict criteria including pain relief and ability to perform prior painful movements is used as the st and ard for evaluating the effect of controlled local anesthetic blocks , the diagnostic validity of lumbar facet joint nerve blocks may be preserved Study Design This study is a prospect i ve cross-sectional analytic study . Objectives The authors determined the prevalence and clinical features of patients with pain stemming from the lumbar zygapophysial joints . Summary of Background Data Previous studies have demonstrated a wide range of prevalence for zygapophysial joint pain and conflicting results with regard to clinical signs . Methods One hundred and seventy-six consecutive patients with chronic low back pain were investigated with a series of screening zygapophysial joint blocks using lignocaine and confirmatory blocks using bupivacaine . Results Forty-seven percent of patients had a definite or greater response to the screening injection at one or more levels but only 15 % had a 50 % or greater response to a confirmatory block . Response to zygapophysial joint injection was not associated with any single clinical feature or set of clinical features . Conclusions The zygapophys 
    Output:
    
agent
***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: Study Design . This was a prospect i ve observational study of patients with low back pain and those without after laminotomy and discectomy .  Objectives . To determine , using a strict experimental design , the relative pain intensity response to provocative discography in symptomatic and asymptomatic subjects after lumbar discectomy for intervertebral disc herniation . Background . Provocative discography frequently is used to evaluate persistent or recurrent low back pain syndromes in patients who have undergone posterior discectomy . The validity of interpreting painful injections during this procedure has not been critically assessed . The prevalence of significantly painful disc injections in a group with good outcomes after surgery is not known . Knowing the rates of significantly painful injections in asymptomatic patients after lumbar discectomy may clarify the meaning of painful injections in symptomatic patients . Methods . From a cohort of 240 patients who had undergone single-level limited discectomy for sciatica , 20 asymptomatic volunteers were recruited for experimental three-level lumbar discography . Inclusion criteria required nearly perfect scores on st and ardized back pain rating instruments , no other spinal pathology , and normal psychometric screening . A control group of 27 symptomatic patients , after single-level discectomy with intractable low back pain syndrome , and without other spinal pathology , underwent discography . Seven patients in the control group had normal psychometric tests . Experienced raters who were blinded to control versus experimental status of the subjects scored the magnetic resonance imaging , discogram , psychometric tests , and discography videotapes of the subjects ’ pain behavior . Results . There were 8 of 20 ( 40 % ) positive injections of discs that had previous surgery in the asymptomatic group and 17 of 27 ( 63 % ) positive injections in the symptomatic group . Specifically with regard to the symptomatic group , there were 3 of 7 ( 43 % ) positive injections ( all concordant ) in patients with normal psychometric scores , as compared with 14 of 20 ( 70 % ) positive injections ( 12 concordant ) in patients with abnormal psychometric scores . Injections of discs that had previous surgery result ed in a mean pain score of 2.1 of 5 in the asymptomatic group , 2.1 in the symptomatic group with normal psychometric scores , and 3.4 in the symptomatic group with abnormal psychometric scores . Of the discs not treated with surgery , 2 were positive in the asymptomatic group ( 10 % ) , 3 in 2 symptomatic subjects with normal psychological testing ( 29 ) , and 18 in 13 symptomatic subjects with abnormal psychometric testing ( 76 % ) . Conclusions . A high percentage of asymptomatic patients with normal psychometric testing who previously have undergone lumbar discectomy will have significant pain on injection of their discs that had previous surgery ( 40 % ) . This is not significantly different from the experience of symptomatic patients with normal psychometric testing undergoing discography on discs that had previous surgery . Patients with abnormal psychological profiles have significantly higher rates of positive disc injections than either asymptomatic volunteers or symptomatic subjects with normal psychological screening BACKGROUND Patients with chronic low back pain present physicians with diagnostic and therapeutic problems . Physical treatments tend to have low success rates and it is postulated that this may be because low back pain can be a manifestation of abnormal illness behaviour . METHODS A structured prospect i ve study determined the prevalence of somatization in a sample of 131 adult patients with chronic low back pain using the Illness Behaviour Question naire ( IBQ ) and the Modified Somatic Perception Question naire ( MSPQ ) . The scores on these psychological question naires were compared with the blind interpretation of pain distribution drawings and with the results of a mechanical classification of the patient 's symptoms and signs . RESULTS Fifty-four per cent of patients had four or more ( out of five ) abnormal illness indicators . The MSPQ values for the group were significantly above the control values in the literature . Thirty-two per cent of pain diagrams were thought to be incompatible with an organic cause when assessed by an orthopaedic surgeon and sixty-two per cent when assessed by a psychiatrist . CONCLUSIONS Psychosocial factors are dominant in the presentation of chronic low back pain in adults and the disorder is not primarily a musculoskeletal one An attempt was made to determine the relative contribution of various structures to chronic low back pain , including facet joint(s ) , disc(s ) , and sacroiliac joint(s ) in a prospect i ve evaluation . Precision diagnostic blocks , including disc injections , facet joint blocks , and sacroiliac joint injections , are frequently used . In contrast , selective nerve root blocks or transforaminal epidural injections are used occasionally to evaluate persistent or recurrent low back pain in patients without appropriate radiologic or neurophysiologic diagnosis . One hundred and twenty patients with a chief complaint of low back pain were evaluated with precision diagnostic injections , which included medial branch blocks , provocative discography and sacroiliac joint injections . In 40 % ( 95 % CL , 31 % , 49 % ) , of the patients , facet joint pain was diagnosed ; and in 26 % ( 95 % CL , 18 % , 34 % ) of the patients discogenic pain was diagnosed ; and 2 % of the patients were diagnosed with sacroiliac joint pain OBJECTIVE To evaluate the prevalence of facet joint pain in patients with chronic low back pain ( CLBP ) after surgical intervention(s ) . DESIGN A prospect i ve , nonr and omized , consecutive study . SETTING An ambulatory interventional pain management setting . PARTICIPANTS The prevalence of facet joint pain was evaluated in patients with CLBP after various surgical intervention(s ) referred to an interventional pain management practice . The sample was derived from 282 patients with persistent CLBP after various surgical intervention(s ) . Of these , 242 patients consented to undergo interventional techniques .  A total of 117 consecutive patients with chronic , nonspecific low back pain , after lumbar surgical intervention(s ) were evaluated with controlled , comparative local anesthetic blocks . INTERVENTIONS Controlled , comparative local anesthetic blocks ( 1 % lidocaine or 1 % lidocaine followed by .25 % bupivacaine ) under fluoroscopic visualization using 0.5mL to block each facet joint nerve . MAIN OUTCOME MEASURES A positive response was defined as at least 80 % reduction of pain with ability to perform previously painful movements . A positive response was considered to be pain relief from the lidocaine block lasting at least 1 hour or at least 2 hours or greater than duration of relief with lidocaine when bupivacaine was used . Controlled , comparative local anesthetic blocks were used to eliminate false-positive results . Valid information is only obtained by performing controlled blocks in the form of comparative local anesthetic blocks , in which , on 2 separate occasions , the same joint is anesthetized by using local anesthetics with different duration s of action . If patients obtained appropriate response with both blocks , they were considered a positive . If they obtained appropriate response with lidocaine but not with bupivacaine , they were considered false-positive , whereas if the response was negative with lidocaine , they were considered negative . RESULTS The prevalence of lumbar facet joint pain in patients with recurrent pain after various surgical intervention(s ) was 16 % ( 95 % confidence interval , 9%-23 % ) . The false-positive rate with a single block with lidocaine was 49 % . CONCLUSIONS Facet joints are clinical ly important pain generators in a small but significant proportion of patients with recurrent CLBP after various surgical intervention(s ) BACKGROUND Psychological disorders may be associated with poor pain related treatment outcomes . However , there may be limitations with studies evaluating the relationship between pain and psychopathology . OBJECTIVE To assess the reliability of  psychological evaluations  in interventional pain management by MCMI-III(R ) and P-3(R ) . STUDY DESIGN Prospect i ve evaluation of consecutive patients in an interventional pain management center . METHODS Patients were evaluated using a DSM-IV-TR(R ) question naire with a physician interview as an integral part of their comprehensive evaluation . In addition , all the patients participating in this study also underwent psychological evaluation with MCMI-III and P-3 . A positive diagnosis of major depression or generalized anxiety disorder based on DSM-IV-TR criteria was considered as the criterion st and ard . All of the patients presented for treatment of chronic pain . The data based on the criterion st and ard were compared with results of the diagnostic impression from the MCMI-III and the P-3 evaluation utilizing criteria for average , and above average , patient pain scores . RESULTS Major depression was diagnosed in a total of 59 of 100 patients using DSM-IV-TR criteria , in 32 patients based on MCMI-III criteria , and in 55 patients based on P-3 evaluations utilizing average pain patient criteria . Generalized anxiety disorder was diagnosed in 55 patients by means of DSM-IV-TR , 45 patients by MCMI-III , and 55 patients by P-3 Profile utilizing average pain patient scores . The specificity of MCMI-III was 100 % with a sensitivity of 54 % for diagnosis of depression ; whereas it was 78 % specificity and sensitivity for P-3 , with average pain patient scores . For generalized anxiety disorder , specificity of MCMI-III was 89 % with a sensitivity of 73 % compared to specificity of 80 % and sensitivity of 84 % for average pain patient scores for P-3 . CONCLUSION MCMI-III and P-3 are highly specific in diagnosing depression and generalized anxiety disorder , with variable sensitivity . A DSM-IV-TR question naire evaluation incorporated into the pain management question naire , along with a short clinical interview , is a reliable means of assessing depression and anxiety in patients suffering with chronic pain Study Design . A prospect i ve cross-sectional analytic approach was taken . Objectives . This study sought to determine the relative contribution of the disc and the zygapophyseal Joint as a pain source in patients with chronic low back pain . Summary of Background Data . Previous studies have employed either zygapophyseal joint blocks or discography , but in no studies have both procedures been performed . Methods . Ninety-two consecutive patients with chronic low back pain were studied using both discography and blocks of the zygapophyseal joints . Results . Thirty-six patients ( 39 % ) had at least one positive discogram as defined by exact pain reproduction , an abnormal image , and a negative control . Eight patients responded to both a screening zygapophyseal joint block using lignocaine and confimatory block using bupivacaine . Only three patients had both a positive discogram and a symptomatic zygapophyseal joint . Conclusions . In patients with chronic low back pain , the combination of discogenic pain and zygapophyseal joint pain is uncommon BACKGROUND Lumbar facet ( zygapophysial ) joints have been implicated as the source of chronic pain in 15 % to 45 % of patients with chronic low back pain . Diagnosis may be confounded by false-positive results with a single diagnostic block and administration of anxiolytics and narcotics prior to or during the diagnostic facet joint blocks . OBJECTIVE To evaluate the effect of midazolam and fentanyl on the diagnostic validity of of lumbar facet joint pain . STUDY DESIGN R and omized , prospect i ve , double-blind , placebo-controlled evaluation . METHODS The design consisted of a placebo group receiving sodium chloride solution and two experimental groups receiving either midazolam or fentanyl . The patients included in the study were diagnosed with facet joint pain with controlled comparative local anesthetic blocks of medial branches or L5 dorsal rami . They had been treated with lumbar facet joint nerve blocks with good pain relief , and were presenting for repeat treatment after a period of symptom relief . The study was undertaken in an interventional pain management practice . OUTCOME MEASURES Outcomes were assessed at baseline and after the administration of 1 of the 3 solutions ( Group I , sodium chloride solution ; Group II , midazolam ; or Group III , fentanyl ) . Outcome measures included numeric pain scale , proportion of pain relief , and ability to perform prior painful movements . RESULTS Pain relief of > or = 80 % was noted in 2 % of the patients in Group I , 5 % of the patients in Group II , and 7 % in Group III . Pain relief of > or = 50 % was noted in 7 % of the patients in Group I , 5 % of the patients in Group II , and 13 % of the patients in Group III . There were no significant differences among the groups . CONCLUSION The administration of sedation with midazolam or fentanyl is a confounding factor in the diagnosis of lumbar facet joint pain in patients with chronic low back pain . However , this study suggests that if strict criteria including pain relief and ability to perform prior painful movements is used as the st and ard for evaluating the effect of controlled local anesthetic blocks , the diagnostic validity of lumbar facet joint nerve blocks may be preserved Study Design This study is a prospect i ve cross-sectional analytic study . Objectives The authors determined the prevalence and clinical features of patients with pain stemming from the lumbar zygapophysial joints . Summary of Background Data Previous studies have demonstrated a wide range of prevalence for zygapophysial joint pain and conflicting results with regard to clinical signs . Methods One hundred and seventy-six consecutive patients with chronic low back pain were investigated with a series of screening zygapophysial joint blocks using lignocaine and confirmatory blocks using bupivacaine . Results Forty-seven percent of patients had a definite or greater response to the screening injection at one or more levels but only 15 % had a 50 % or greater response to a confirmatory block . Response to zygapophysial joint injection was not associated with any single clinical feature or set of clinical features . Conclusions The zygapophys 
    Output:
    