Clinical outcome of sural nerve biopsy: a retrospective study.

Sural nerve biopsy is a valuable tool in establishing the diagnosis and investigating the underlying causes of peripheral neuropathies. Few investigations have been carried out in which the sequelae of this procedure have been described systematically. We studied the short-term adverse reactions in 110 patients and the long-term outcome of sural nerve biopsy in a subgroup of 54 patients after 5-32 months. Long-lasting sensory deficits were reported in 93%, dysaesthesia in 19% and mild persistent pain in 33% of the 54 patients. No significant differences were found between patients followed for 1-2 years and those followed for more than 2 years in the frequency and distribution of hypaesthesia and anaesthesia. However, dysaesthesia was less frequent after more than 2 years (6/32 vs 1/16), and persistent pain completely subsided within our observation period. We conclude that disabling sequelae regress and finally subside over time. If we assume that returning for follow-up visits may cause bias towards more severely affected patients, the overall prognosis may be even better.