Dental extraction-associated cerebral abscess caused by Parvimonas micra.

Background: Dental extraction-associated cerebral abscesses are rare. To date, Parvimonas micra has not been reported as the causative organism of such abscesses. Case Description: A 66-year-old male presented with generalized seizures 12 days after molar extraction. He had been diagnosed with periodontitis 4 years earlier. Following the extraction, he was prophylactically administered clarithromycin for 1 week. At presentation, he exhibited left hemiparesis and dysarthria, with a body temperature of 38.0℃. Blood tests revealed mild elevations in white blood cell count and serum C-reactive protein levels. Echocardiography revealed no abnormalities. Cerebral magnetic resonance imaging demonstrated a cystic mass in the right frontal lobe, accompanied by rim-like enhancement and extensive perilesional edema, as well as hyperintensity on a diffusion-weighted sequence. The patient underwent burr-hole drainage, which yielded purulent discharge. Culture of the pus isolated P. micra and Fusobacterium nucleatum. Conclusion: Cerebral abscesses may develop following dental extraction, and careful observation is required afterward. Early onset of neurological symptoms after dental extraction should raise suspicion of a cerebral abscess requiring timely surgical intervention.