Metronidazole-induced toxicity of the central and peripheral nervous system.

A woman in her 80s was admitted with a growing feeling of dizziness, tingling and vomiting that began a week before. The neurological examination showed dysarthria, downbeat nystagmus and gait ataxia. At the time, she was taking antibiotics (1 g amoxicillin and 500 mg metronidazole every 8 hours) following surgery for a mandibular abscess a month earlier.Brain MRI showed T2 and FLAIR hyperintensities in dentate nuclei and splenium of the corpus callosum, findings described in metronidazole neurotoxicity. Metronidazole was discontinued, with resolution of all symptoms except lower limb paraesthesias.Given the ageing population and the increasing use of pharmacological treatments for multiple conditions, drug-induced neurological complications are receiving growing attention, yet they often remain underrecognised. Metronidazole neurotoxicity is a rare adverse effect that should be considered especially during prolonged treatments. The most frequent debut resembles this case, with cerebellar dysfunction as the most common central nervous system toxicity and concomitant polyneuropathy frequently associated.