Diagnostic value of nerve and muscle biopsy in suspected vasculitis cases.

OBJECTIVES

To evaluate the diagnostic value of nerve and muscle biopsy in suspected cases of vasculitis and their correlation with the clinical and electrophysiological data.

METHOD

We conducted a retrospective review of I 15 nerve and muscle biopsy specimens from cases in the past 20 years at the University of Alabama at Birmingham (UAB) Muscle and Nerve Histopathology Laboratory. Clinical and electromyography data in available cases were analyzed to evaluate the histopathologic correlation,:

RESULTS

: The diagnostic sensitivity of nerve biopsy was 39%, Nerve biopsy showed a statistically higher diagnostic yield (P = 0-0001) than muscle biopsy (17%), although muscle biopsies resulted in a more definite diagnosis m 3%. of cases. The highest diagnostic yield (73%) of vasculitis on nerve biopsy was observed in patients with known rheumatologic disease and accompanying neuropathy or myopathy. Nerve conduction study was able to identify diffuse neuropathy in the majority of patients with vasculitis, including asymptomatic neuropathy. Abnormal sural nerve conduction was highly correlated (P = 0.03) with positive nerve biopsy. There was a wide spectrum of neurologic manifestations in vasculitic neuropathy, with the most common clinical manifestation of vasculitic neuropathy being polyneuropathy.

CONCLUSIONS

Nerve biopsy is superior to muscle biopsy for the diagnosis of vasculitis among suspected cases of vasculitis. The highest diagnostic yield of nerve biopsy is observed when patients with known rheumatologic diseases have neuropathy or myopathy. Abnormal sural nerve conduction can be used as a guide for nerve biopsy.