***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: There are no data on the prevalence and other epidemiologic characteristics of  chronic symmetric polyneuropathy ( CSP ) in the community . This study was design ed to assess the prevalence and risk factors of CSP  in well-defined elderly ( 55 years and older ) population s from two separate areas in Italy . Thirty-five general practitioners working in the two areas were invited to interview a r and om sample of patients requesting consultation . They used a pretested question naire which focused on selected symptoms of polyneuropathy , common risk factors for CSP , and current drug treatments . Patients giving affirmative answers to the questions on screening symptoms received a further clinical evaluation by a neurologist . Details are given of the general characteristics of the study areas and population s , the methods of case ascertainment , the validation of the screening instruments , and the results of a pilot study Objective This project evaluated the utility of quantitative sensory techniques in predicting the development of neuropathy for subjects participating in a prospect i ve study . Research Design and Methods Distal symmetric polyneuropathy was evaluated in 77 insulin-dependent diabetes mellitus individuals via quantitative sensory testing , nerve conduction studies , and clinical examination . Results Although the specificity and positive predictive value were low for the quantitative sensory techniques as predictors of neuropathy diagnosed on clinical exam ∼2 yr later , the sensitivity for vibratory thresholds was high ( 100 % ) . Variability over the 2-yr interval was shown on follow-up testing for each of the objective assessment modalities and it was not explained by differences for potential risk factors measured at baseline . Conclusion Despite a cross-sectional relationship between the assessment modalities and clinical ly overt neuropathy at baseline , these follow-up data suggest that the potential for the objective modalities as predictors of clinical ly diagnosed neuropathy may be limited Article abstract -Despite prominent symptoms of neuropathic pain , patients with small-fiber sensory neuropathies have few objective abnormalities on clinical examination and routine electrodiagnostic studies . We quantified intraepidermal nerve fiber ( IENF ) density in sections of skin obtained by punch skin biopsy , and found it to be significantly reduced in patients with painful sensory neuropathies compared with age-matched control subjects . In addition , IENF density correlated with clinical estimates of neuropathy severity , as judged by the extent of clinical ly identifiable sensory abnormalities . IENF density at the calf was lower than that obtained from skin at more proximal sites , indicating the length dependency of small-fiber loss in these neuropathies . NEUROLOGY 1997;48 : 708 - We assessed the involvement of somatic unmyelinated fibers in sensory ganglionopathies by skin biopsy and quantitative sensory testing ( QST ) .  Sixteen patients with ganglionopathy , 16 with axonal neuropathy , and 15 normal controls underwent skin biopsy at the proximal thigh and the distal leg .  Intraepidermal nerve fibers ( IENF ) were immunostained by antiprotein gene product 9.5 , and their linear density was quantified under light microscopy . Confocal microscopy studies with double staining of nerve fibers and basement membrane were also performed . Healthy subjects and neuropathy patients showed the typical proximodistal gradient of IENF density ; in neuropathies , values were significantly lower at the distal site of the leg , confirming the length-dependent loss of cutaneous innervation . Conversely , ganglionopathy patients with hyperalgesic symptoms did not show any change of IENF density between the proximal thigh and the distal leg . The distinct pattern of epidermal denervation seen in sensory ganglionopathy reflected the degeneration of somatic unmyelinated fibers in a fashion that was not length-dependent , which was consistent with both clinical and neurophysiologic observations and supported the diagnosis 
    Output:
    
The literature indicates that symptoms alone have relatively poor diagnostic accuracy in predicting the presence of polyneuropathy ; signs are better predictors of polyneuropathy than symptoms ; and single abnormalities on examination are less sensitive than multiple abnormalities in predicting the presence of polyneuropathy .
The combination of neuropathic symptoms , signs , and electrodiagnostic findings provides the most accurate diagnosis of distal symmetrical polyneuropathy .
The highest likelihood of polyneuropathy ( useful for clinical trials ) occurs with a combination of multiple symptoms , multiple signs , and abnormal electrodiagnostic studies .
A modest likelihood of polyneuropathy ( useful for field or epidemiological studies ) occurs with a combination of multiple symptoms and multiple signs when the results of electrodiagnostic studies are not available .
A lower likelihood of polyneuropathy occurs when electrodiagnostic studies and signs are discordant .
The inclusion of this formalized case definition in clinical and epidemiological research studies will ensure greater consistency of case selection