Solitary brainstem abscess and metronidazole-induced encephalopathy: A case report

<h2>Abstract</h2> Solitary brain abscesses are rare and present high mortality rates and treatment challenges. Metronidazole-induced encephalopathy is a rare neurological complication associated with prolonged metronidazole use. Here, we present the case of a 48-year-old woman who had undergone cervical laminectomy 3 months before presenting with progressive headache, left ptosis, right limb weakness, right facial paralysis, and unsteadiness. Enhanced T1-weighted brain magnetic resonance imaging revealed a ring-enhancing lesion in the left midbrain, raising suspicion of a brainstem abscess. Broad-spectrum antibiotics (ceftriaxone 4 g/d and metronidazole 2 g/d) were administered; however, after 6 weeks, metronidazole-induced encephalopathy occurred. After discontinuing metronidazole, her clinical symptoms and the bilateral dentate lesion improved. The patient has since resumed her regular daily activities.