***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: The authors compared ultrasonography with electrophysiology for the diagnosis of  carpal tunnel syndrome ( CTS ) on 110 clinical ly affected wrists . An increased cross sectional area in the proximal carpal tunnel larger than 0.11 cm2 in combination with compression signs on longitudinal scans proved to be highly predictive for CTS ( sensitivity , 89.1 % ; specificity , 98.0 % ) . Ultrasound was comparable to electrophysiology in the diagnosis of CTS , and in 35 % of cases changes in morphology suggested a specific therapeutic strategy PURPOSE To compare the diagnostic value of high-resolution ultrasound ( US ) with nerve conduction studies ( NCS ) in patients with clinical ly defined carpal tunnel syndrome ( CTS ) . METHODS A prospect i ve study was conducted on 66 consecutive patients investigated for sensory h and symptoms . The gold st and ard was the clinical diagnosis of CTS . RESULTS NCS showed greater diagnostic sensitivity ( 82 % ) than US ( 62 % ) in supporting a diagnosis of CTS . With increasing neurophysiologic severity of median neuropathy , there was increasing convergence of the two test methods . Abnormal US as the only diagnostic supportive evidence of CTS was rare . However , the positive predictive value of US for CTS was 100 % . CONCLUSION NCS show better sensitivity than US in supporting a diagnosis of CTS . However , because of its high positive predictive value , one may consider using US as a screening test , eliminating the need for NCS in the majority of clinical suspicion of CTS and reserving NCS for cases in which US is negative OBJECTIVE The few papers published on the use of sonography in carpal tunnel syndrome suggest it may be a useful diagnostic test . This study aims to prospect ively evaluate the use of sonographic measurements of the median nerve in the diagnosis of carpal tunnel syndrome . SUBJECTS AND METHODS Patients with documented carpal tunnel syndrome and a group of asymptomatic control subjects were enrolled and underwent high-resolution sonography of the carpal tunnel . A small-footprint linear array transducer was used to scan and measure the median nerve cross-sectional area and the maximum transverse and anteroposterior diameters . Data from the patient group and the control group were compared to establish optimal diagnostic criteria for carpal tunnel syndrome . RESULTS Sixty-eight carpal tunnel syndrome patients ( 50 women , 18 men ) with 102 affected nerves and 68 nerves in 36 asymptomatic controls ( 23 women , 13 men ) were examined .  Qualitative assessment alone was found to be unreliable . All measurements showed significant differences between patients and controls . The most predictive measurement was swelling of the median nerve , which was significantly greater in carpal tunnel syndrome patients compared with controls ( mean , 0.13 cm2 versus 0.07 cm2 ) . Thus , quantitative assessment of the median nerve provides an accurate diagnostic test ( sensitivity , 82 % ; specificity , 97 % ) , with an area larger than 0.09 cm2 being highly predictive of carpal tunnel syndrome . CONCLUSION We confirm that median nerve cross-sectional area measurement correlates well with the presence of carpal tunnel syndrome and is both sensitive and specific for the diagnosis OBJECTIVE The aim of this study is twofold . First , to assess the relationships between the cross-sectional area ( CSA ) of the median nerve ( MN ) calculated at ultrasound ( US ) and : ( 1 ) patient 's perception of his/her symptoms and h and function ; ( 2 ) clinical severity of CTS ; ( 3 ) neurophysiological classification ; ( 4 ) h and distribution of symptoms . Second , to assess the sensitivity of ultrasonography ( US ) and neurophysiology in the diagnosis of CTS using clinical measures as gold st and ard . METHODS We performed a prospect i ve study by using multidimensional assessment : clinical ( Historic and Objective scale , Hi-Ob ) , neurophysiological , patient-oriented measures ( Boston Carpal Tunnel Question naire , BCTQ ) and high-resolution US . The dominant h and s of 54 consecutive patients who were referred to our neurophysiologic laboratory with clinical signs of CTS ( 43 females , mean age 53.3 , range 30 - 80 , SD : 13.1 ) were examined . RESULTS A statistically significant correlation was found between the CSA of the MN at wrist and ( 1 ) h and function ( according to BCTQ , r=0.35 , p=0.01 ) , ( 2 ) clinical scale ( Hi-Ob scale , r=0.51 , p<0.00007 ) , ( 3 ) neurophysiologic classification ( r=0.80 , p<0.0000001 ) , and ( 4 ) h and distribution of symptoms ( p=0.017 ) . Neurophysiology showed higher sensitivity than US but in one of 3 cases with normal neurophysiological results , US showed data suggestive of CTS . CONCLUSIONS A positive correlation exists between US findings and all the conventional measures of CTS severity . The sensitivity of the combination of US and neurophysiology is higher than the sensitivity of neurophysiology or US alone . US is a useful complementary tool for CTS assessment . SIGNIFICANCE Information on the contribution of US in CTS and the interpretation of severity measurements in CTS PURPOSE To determine whether sonography can be an alternative method to nerve conduction study ( NCS ) in the diagnosis of carpal tunnel syndrome ( CTS ) , by comparing sonography with nerve conduction study using clinical diagnosis as the reference st and ard . METHODS Forty-one wrists of 29 patients were enrolled , along with the same number of age- and gender-matched controls . All patients had sonographic measurement of the cross-sectional area ( CSA ) of the median nerve and NCS . Sensitivity and specificity were obtained and compared between sonography and NCS . RESULTS There were no significant differences in age , gender , body mass index and involved side between patients and controls ( p<.05 ) . The CSA at the tunnel inlet was significantly larger in patients than in controls ( p=.03 ) . The best cutoff value of CSA at the tunnel inlet was 10.7 mm(2 ) , which had a sensitivity of 66 % and a specificity of 63 % . NCS showed a sensitivity of 78 % and a specificity of 83 % . Sensitivity was similar between sonography and NCS ( p=0.27 ) , whereas specificity was significantly lower in sonography than in NCS ( p=0.02 ) . CONCLUSIONS Sonography is not accurate enough to replace NCS for the diagnosis of CTS . TYPE OF STUDY /LEVEL OF EVIDENCE Diagnostic III OBJECTIVE To evaluate the diagnostic value of ultrasonography in patients with electrophysiologically confirmed carpal tunnel syndrome . DESIGN A prospect i ve  ultrasonographic study of 70 wrists with electrophysiologically confirmed carpal tunnel syndrome and of 80 normal wrists . Receiver-operating-characteristics curves for the ultrasonographic measurements of median nerve were plotted to identify the most optimal cutoff values . RESULTS The ultrasonographic measurements of median nerves were found to be increased significantly in patients with carpal tunnel syndrome when compared with controls , particularly in terms of cross-sectional area ( P < 0.001 ) . According to receiver-operating-characteristics curve results , the most optimal cutoff value for the cross-sectional area of the median nerve was obtained at the level of middle carpal tunnel , which was 9.3 mm2 , with a sensitivity of 80 % and specificity of 77.5 % . CONCLUSION Ultrasonographic examination of the median nerve seems to be a promising method in the diagnosis of carpal tunnel syndrome , evaluating the morphologic changes of the median nerve in patients with clinical signs and symptoms . Further studies with wider series are needed to confirm our preliminary results Background : Carpal tunnel syndrome ( CTS ) is a common entrapment neuropathy . Electrodiagnostic testing ( EMG ) is used to confirm the diagnosis . It is not known what the diagnostic accuracy of high-resolution sonography is in comparison to EMG . Objective : The aim of this study was to compare the diagnostic accuracy of both tests in CTS patients . Methods : A prospect i ve cohort of 207 patients with possible CTS underwent high-resolution sonography and EMG . The diagnosis of CTS was based on clinical signs and symptoms . The cross-sectional area of the median nerve at the carpal tunnel inlet and at the distal one-third level of the forearm was assessed by an investigator , blinded to the clinical and EMG data . Normal sonographic values were obtained from 137 controls . All patients and 40 controls underwent a st and ardised nerve conduction study . The kappa coefficient was used to evaluate the relationship between sonography , EMG and clinical diagnosis . Results : The cross-sectional area at the distal one-third of the forearm was not significantly different between the controls and patients ( p = 0.59 ) , whereas the cross-sectional area at the carpal tunnel inlet was significantly increased in the patient group ( p<0.0001 ) . The kappa coefficient for EMG using the median-ulnar distal sensory latency difference versus clinical evaluation was 0.64 and , for sonography , this coefficient was 0.69 ; these were not statistically different ( p = 0.37 ) . Combining the two tests result ed in a kappa coefficient of 0.72 , which was not significantly different from sonography alone ( p = 0.73 ) . Conclusion : In patients with a clinical diagnosis of CTS , the accuracy of sonography is similar to that for EMG . Sonography is probably preferable because it is painless , easily accessible and preferred by the patients BACKGROUND There is no clear-cut consensus on the best diagnostic criteria for carpal tunnel syndrome . The objective of this study was to compare the probability of carpal tunnel syndrome being present following electrodiagnostic testing with the probability of it being present after the diagnosis was established on the basis of a clinical evaluation alone . METHODS The study sample included patients with any peripheral nerve diagnosis who had been referred to the electrodiagnostic laboratory of an academic health-care center . The probability of carpal tunnel syndrome before electrodiagnostic testing ( pretest probability ) was estimated with use of the CTS-6 , a vali date d clinical diagnostic aid that is used to estimate the probability of carpal tunnel syndrome on the basis of the presence or absence of six clinical findings recorded as part of the history or noted on physical examination . All patients then underwent a st and ard electrodiagnostic assessment of the median nerve by a neurologist blinded to the result of the CTS-6 evaluation . Sensory nerve conduction velocity was used to classify the result of the electrodiagnostic testing as either positive or negative for carpal tunnel syndrome with use of two different criteria ( one stringent and one lax ) derived from the literature . The main outcome measure was the difference between the pretest and posttest probabilities of carpal tunnel syndrome . RESULTS One hundred and forty-three patients were studied . The pretest probability of carpal tunnel syndrome ranged between 0.10 and 0.99 ( mean [ and st and ard deviation ] , 0.81 + /- 0.22 ) . Seventy-three percent of the patients had a pretest probability of at least 0.80 . The average change in probability for these patients was -0.02 when the stringent electrodiagnostic criterion was used and -0.06 when the lax criterion was used . With either electrodiagnostic criterion , the majority of the large changes in probability were for patients for whom the pretest probability was < or = 0.50 . The probability of carpal tunnel syndrome was lowered after the electrodiagnostic testing in most of these cases . CONCLUSIONS For the majority of patients who are considered to have carpal tunnel syndrome on the basis of their history and physical examination alone , electrodiagnostic tests do not change the probability of diagnosing this condition to an extent that is clinical ly relevant The utility of electrodiagnostic testing in the evaluation of carpal tunnel syndrome ( CTS ) has been question ed . We studied patients who met the clinical criteria for CTS and compared patients who had normal nerve conduction studies ( NCS ) with patients who had abnormal NCS . We found that 25 % of the CTS patients without confounding neurologic disorders had normal NCS with median palmar nerve stimulation .  Patients with abnormal NCS were older and heavier and had more clinical features of CTS . NCS results could not be predicted accurately from clinical features by use of logistic regression models . This was especially true in clinical ly borderline cases . NCS did not predict the outcome of conservative management . We concluded that NCS provide independent information in the evaluation of suspected CTS , especially when fewer clinical criteria are present , but that NCS are not helpful in predicting the outcome of nonsurgical management The diagnosis of carpal tunnel syndrome ( CTS ) is mainly based on clinical findings and electrodiagnostic tests ( EDT ) . However , EDT results do not support clinical findings in some cases . It has been recently suggested that ultrasonography ( US ) can be used to diagnose CTS . In this study , we aim ed to investigate whether US has a diagnostic value for CTS in patients with negative EDT findings or not . EDT was performed on 319 wrists with clinical CTS findings in electrophysiology laboratory .  Median and ulnar nerve conduction velocities were measured in all cases and electromyography was performed in patient with tenar atrophy and having suspicion involvement of brachial plexus as EDT . Fifty-nine wrists with negative EDT ( study group ) and 30 wrists from 15 healthy individuals ( control group ) were examined using US . The mean of cross-sectional areas ( CSAs ) measurements were found 8.83+/-3.05 mm2 by tracing method ( TM ) and 8.51+/-3.13 mm2 by ellipsoid formula ( EF ) in study group , and 7.63+/-1.52 mm2 by TM and 7.66+ 
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Conclusions The wide variations of sensitivities and specificities reported in the literature have prevented meaningful analysis of ultrasound as either a screening or confirmatory tool in the diagnosis of CTS .
Although ultrasound may not replace electrodiagnostic testing as the most sensitive and specific test for the diagnosis of CTS given the values reported in this meta- analysis , it may be a feasible alternative to electrodiagnostic testing as the first-line confirmatory test .