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MRI Findings and Topographic Distribution of Lesions in Metronidazole-Induced Encephalopathy
Ambreen Fatima1, Sachin Khanduri1, Sadaf Sultana1
1Radiodiagnosis, Era's Lucknow Medical College and Hospital, Lucknow, IND.
Abstract:
Purpose This study aims to describe the magnetic resonance imaging (MRI) of the brain of five patients diagnosed with metronidazole-induced encephalopathy (MIE). In addition, the aim of our study was to better define the topographic distribution of lesions in MIE. Methods We retrospectively evaluated MRI findings before and after drug cessation in five patients diagnosed with MIE at Era's Lucknow Medical College and Hospital, Lucknow, Uttar Pradesh, India. The main MRI signal changes and lesion locations were studied. Results Among the patients observed, the average age of the patients with MIE was 55 years (range: 30-70 years). Cerebellar dysfunction, mainly ataxia, and altered mental status were seen in the majority of cases. The most frequently involved sites were the dentate nucleus (cerebellum), brain stem, and corpus callosum (splenium). In diffusion-weighted imaging (DWI), most lesions did not show true restricted diffusion, except for a solitary corpus callosum lesion. Conclusion Although drug-related side effects are more common with long-term use of metronidazole, they may also occur with high doses for short durations. The dentate nucleus, the splenium in the corpus callosum, and the brain stem are the most affected structures. Apart from a solitary lesion of the corpus callosum, all identified lesions were reversible at follow-up MRI after discontinuation of metronidazole. The clinical presentation and characteristic MRI changes are highly specific and can be correlated to make a rapid and more accurate diagnosis of this potentially treatable condition. Prognosis is excellent if detected early.
Insights
Metronidazole-induced encephalopathy (MIE) can cause cerebellar dysfunction and altered mental status. Characteristic MRI findings in the dentate nucleus, brain stem, and corpus callosum are reversible upon drug cessation, indicating an excellent prognosis.
Area of Science:
- Neurology
- Radiology
- Toxicology
Background:
- Metronidazole is an antibiotic with potential neurotoxic side effects.
- Metronidazole-induced encephalopathy (MIE) is a rare but serious adverse drug reaction.
- Understanding the neuroimaging patterns of MIE is crucial for timely diagnosis and management.
Purpose of the Study:
- To describe the brain magnetic resonance imaging (MRI) findings in patients with metronidazole-induced encephalopathy (MIE).
- To define the topographic distribution of MIE lesions.
- To correlate MRI findings with clinical presentation for accurate diagnosis.
Main Methods:
- Retrospective evaluation of MRI scans in five MIE patients.
- Analysis of MRI signal changes and lesion locations before and after metronidazole cessation.
- Review of clinical data including symptoms and patient demographics.
Main Results:
- The most frequently affected brain regions were the dentate nucleus, brain stem, and corpus callosum (splenium).
- Cerebellar dysfunction (ataxia) and altered mental status were common clinical presentations.
- Most lesions showed reversible changes on follow-up MRI after drug discontinuation, except for one corpus callosum lesion.
Conclusions:
- MIE can occur with short-term high-dose metronidazole use, not just long-term therapy.
- Characteristic MRI findings in specific brain areas aid in rapid diagnosis.
- Early detection and discontinuation of metronidazole lead to an excellent prognosis due to lesion reversibility.
