Sensory Neuropathy Associated With Metronidazole: Report of Four Cases and Review of the Literature

Abstract

Objective 

To better characterize sensory neuropathy associated with metronidazole.

Methods 

We report four patients who developed dysesthesias after metronidazole treatment. One received topical metronidazole only. All four underwent electrodiagnostic studies, including nerve conduction studies (NCS), quantitative sensory testing (QST), and quantitative sudomotor axon reflex testing (QSART). One underwent nerve biopsy.

Results 

NCS were normal in all patients. QST showed impaired vibration thresholds in three patients. Three of four patients had abnormal tests of small fiber function. Cooling thresholds were abnormal in one; QSART was abnormal in one and borderline in another. The nerve biopsy specimen showed mild loss of small myelinated axons.

Conclusions 

This study shows that paresthesias associated with metronidazole exposure may be the result of a relatively mild sensory neuropathy with predominant involvement of small fibers and milder, mostly subclinical involvement of large fibers.