DIAGNOSTIC-VALUE OF SURAL NERVE BIOPSY IN CHRONIC INFLAMMATORY DEMYELINATING POLYNEUROPATHY

Objective-To investigate the additional diagnostic value of sural nerv e biopsy of 64 patients in whom chronic inflammatory demyelinating pol yneuropathy (CIDP) was considered, as sural nerve biopsy is recommende d in the research criteria of an ad hoc subcommittee to diagnose CIDP. Methods-Firstly, the additional diagnostic value of sural nerve biops y was analysed with multivariate logistic regression. Six clinical fea tures (remitting course, symmetric sensorimotor neuropathy in arms and legs, areflexia, raised CSF protein concentration, nerve conduction s tudies consistent with demyelination, and absence of comorbidity or re levant laboratory abnormalities) were entered into a logistic model. A fterwards, all significant features identified from this model, as wel l as the results of sural nerve biopsy were forced into a second logis tic model. Secondly, the diagnostic performance of a neurologist exper ienced in diagnosis of peripheral nerve disorders was studied by recei ver operating characteristics (ROC) curve analysis. Results-The result s of the first logistic analysis showed that CSF protein concentration >1 g/l (odds ratio (OR)=38.5) and neurophysiological studies consiste nt with demyelination (OR=51.7) were strong predictors of CIDP. When f orcing the significant features and the sural nerve biopsy data into t he model. an independent predictive value of sural nerve biopsy could not be found. The neurologist was able to discriminate patients with a nd without CIDP (area under the curve (AUC)=0.95). His diagnostic perf ormance did not improve significantly by offering him the results of s ural nerve biopsy. Conclusion-Any additional diagnostic value of sural nerve biopsy in the diagnosis of CIDP could not be shown.