Metronidazole-induced encephalopathy: a systematic review

Area of Science:

• Neurology
• Pharmacology
• Radiology

Background:

• Metronidazole is a common antibiotic with potential central nervous system adverse effects.
• Metronidazole-induced encephalopathy (MIE) is rare, poorly described, and poses diagnostic challenges.
• A detailed understanding of MIE's clinical phenotype is lacking.

Purpose of the Study:

• To systematically review and investigate the clinical features of metronidazole-induced encephalopathy.
• To promote earlier recognition of MIE.
• To elaborate on the phenotypic description of MIE.

Main Methods:

• Systematic literature search of PubMed.gov and reference lists.
• Inclusion of case series and single case reports of MIE.
• Descriptive analysis of extracted patient data.

Main Results:

• 136 patients from 112 papers were included.
• Common symptoms include dysarthria, gait instability, and altered mental status, often with polyneuropathy.
• Characteristic reversible MRI findings (dentate nucleus lesions) were seen in 90% of patients; liver disease was a common comorbidity.

Conclusions:

• MIE should be considered in patients with neurological symptoms related to metronidazole.
• Characteristic MRI findings are highly specific for MIE.
• Early diagnosis and discontinuation of metronidazole lead to good prognosis, especially in patients without severe comorbidity.