A rare clinical presentation of metronidazole-induced dysarthria: A Case report with literature review

Abstract

We described a case of a rare, but notable adverse effect of metronidazole therapy, where a 55-year-old chronic alcoholic patient developed dysarthria following a four-week course of the drug for the treatment of pyogenic liver abscesses. Dysarthria, characterized by slurred or unclear speech, is an uncommon complication of metronidazole, which is generally well-tolerated but has the potential to cause neurotoxic effects in some individuals, especially with prolonged use or high cumulative doses. In this case, the Magnetic Resonance Imaging (MRI) brain revealed T2/FLAIR hyperintensities involving the bilateral dentate nuclei, a key finding associated with metronidazole-induced encephalopathy. The exclusion of other possible causes for dysarthria led to the conclusion that the symptoms were likely induced by metronidazole. This highlights the importance of considering drug-induced neurotoxicity in patients presenting with new neurological symptoms, particularly when there is a history of prolonged antibiotic therapy. The patient's improvement after discontinuing metronidazole and switching to alternative treatment further supports this diagnosis. This case underscores the necessity of closely monitoring patients on metronidazole, especially those receiving prolonged treatment, for any emerging neurological signs. Typical MRI findings play a crucial role in the vigilance for the diagnosis and treatment of such clinical situations. Timely recognition and intervention can help prevent permanent damage and facilitate recovery.

Keywords: Antibiotic; Central nervous system; Cerebellum; Dysarthria; Encephalopathy; Liver abscess; Metronidazole.

Fig. 1

Multiple liver abscesses (pyogenic) are represented by USG abdomen (ANB) (Green colour arrows indicated the abscesses in images [A] and [B]).

Fig. 2

MRI images of the brain at the level of middle cerebellar peduncle shows T2 (A) and FLAIR (B) hyperintensity (indication with white arrow) of bilateral dentate nuclei with T1 (C) hypointensity (indication with white arrow).