Contribution of nerve biopsy to unclassified neuropathy

To evaluate the diagnostic yield of nerve biopsy in patients with peripheral neuropathy of undetermined cause despite extensive diagnostic workup.

From November 2001 through January 2004, 38 patients underwent nerve biopsy because of unclassified neuropathy.

The etiology of the neuropathies could be defined in 14 patients (37%), i.e. in 15% of chronic symmetric, 30% of chronic asymmetric, 50% of subacute symmetric and 62.5% of subacute asymmetric neuropathies. The biopsy was diagnostic in 6 patients (16%), where it showed a vasculitis, and supportive in 8 patients (21%).

The contribution of nerve biopsy to the diagnosis of peripheral neuropathy was highest in acute and subacute asymmetric forms of neuropathy and lowest in chronic symmetric forms. The main indication for nerve biopsy remains the diagnosis of vasculitic neuropathy, a potentially treatable disorder.