Metronidazole Encephalopathy EEG Features: A Case Report with Systematic Review of the Literature

Area of Science:

• Neurology
• Neurophysiology
• Toxicology

Background:

• Metronidazole-induced encephalopathy (MIE) is a rare iatrogenic condition.
• Diagnosis relies on clinical presentation (encephalopathy, seizures, cerebellar signs) and MRI, as EEG findings are poorly described.
• Electroencephalography (EEG) plays a limited role in current MIE diagnostic criteria.

Purpose of the Study:

• To present a detailed longitudinal EEG assessment in a patient with MIE.
• To describe a peculiar and evolving EEG pattern associated with metronidazole toxicity.
• To explore the potential of this EEG pattern as a neurophysiological correlate of cerebellar encephalopathy.

Main Methods:

• Longitudinal EEG monitoring of a single patient with confirmed MIE.
• Detailed analysis of EEG pattern evolution during the acute phase of encephalopathy.
• Systematic literature review on EEG findings in metronidazole-induced encephalopathy.

Main Results:

• The patient exhibited a unique EEG pattern characterized by monomorphic, sharply contoured, symmetric frontal theta activity.
• This EEG pattern demonstrated anterior-posterior progression and correlated with clinical worsening.
• The described EEG activity evolved in parallel with the patient's clinical recovery.

Conclusions:

• The peculiar EEG pattern observed may represent a distinct neurophysiological marker for MIE.
• Further research is needed to validate this EEG finding as a diagnostic correlate for 'cerebellar encephalopathy'.
• This case highlights the importance of considering EEG in the comprehensive evaluation of MIE.