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Updated: Aug 29, 2026
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Metronidazole-induced encephalopathy and inferior olivary hypertrophy: lesion analysis with diffusion-weighted
Jung Im Seok1, Hanseung Yi, Young Min Song
1Movement Disorder Division, Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Background:
Although several cases of metronidazole-induced encephalopathy have been reported, to our knowledge, there is no previous report of brain changes in anterior commissure, basal ganglia, cerebellar white matter, and inferior olivary nuclei on magnetic resonance images. The precise mechanisms of action of metronidazole-induced encephalopathy have not been determined.
Objectives:
To report a unique case of metronidazole-induced encephalopathy extensively involving multiple lesions and to determine the precise mechanism of action of metronidazole-induced encephalopathy.
Setting:
University hospital. Patient A 74-year-old woman hospitalized with complaints of progressive dysarthria, dysphagia, and gait disturbance 3 months after the initiation of metronidazole therapy. Intervention Brain magnetic resonance imaging and discontinuation of metronidazole therapy. Main Outcome Measure We observed changes of multiple lesions found on magnetic resonance imaging and analyzed apparent diffusion coefficient map values.
Results:
Initial fluid-attenuated inversion recovery brain magnetic resonance images showed high signal intensities in diffuse subcortical white matter, anterior commissure, splenium, basal ganglia, midbrain, cerebellar white matter, and bilateral inferior olivary nuclei. These lesions were resolved after discontinuation of metronidazole therapy. However, the lesions in the inferior olivary nuclei were not resolved; rather they became hypertrophic. Apparent diffusion coefficient map values in the symptom period decreased and were normalized after discontinuation of metronidazole therapy.
Conclusions:
We describe a patient with metronidazole-induced encephalopathy involving reversible lesions in the anterior commissure, basal ganglia, and cerebellar white matter, which have not been reported previously. We observed inferior olivary hypertrophy, believed to be the result of lesions in the midbrain and cerebellar white matter rather than the result of lesions induced by metronidazole therapy. By using diffusion-weighted imaging and apparent diffusion coefficient maps, we found that metronidazole-induced encephalopathy might be caused by cytotoxic edema.
Insights
This case study reports metronidazole-induced encephalopathy with novel brain lesions. Diffusion-weighted imaging suggests cytotoxic edema as the cause of these neurological changes.
Area of Science:
- Neurology
- Radiology
- Pharmacology
Background:
- Metronidazole is an antibiotic with known neurotoxic potential.
- Previous reports of metronidazole-induced encephalopathy lack detailed MRI findings in specific brain regions.
- The exact mechanisms underlying metronidazole neurotoxicity remain unclear.
Observation:
- A 74-year-old woman presented with dysarthria, dysphagia, and gait disturbance after 3 months of metronidazole therapy.
- Brain MRI revealed extensive lesions in the anterior commissure, basal ganglia, cerebellar white matter, and inferior olivary nuclei.
- Apparent diffusion coefficient (ADC) values were decreased during the symptomatic period.
Findings:
- Metronidazole-induced encephalopathy demonstrated reversible lesions in the anterior commissure, basal ganglia, and cerebellar white matter.
- Inferior olivary nuclei lesions became hypertrophic despite metronidazole discontinuation.
- Normalization of ADC values post-discontinuation suggests a resolution of cytotoxic edema.
Implications:
- This case expands the spectrum of MRI findings in metronidazole-induced encephalopathy.
- Diffusion-weighted imaging and ADC maps may help elucidate the pathophysiology of metronidazole neurotoxicity.
- Understanding these mechanisms can guide clinical management and diagnosis of drug-induced neurological complications.
