Schaalia odontolytica causing primary intraventricular brain abscess in a child- A case report

Primary intraventricular abscesses are very rare and may be mistaken for intraventricular tumors or other lesions with very few cases reported in literature. Although organisms from the oral cavity are recognized pathogens for brain abscess formation, reports of abscesses caused by Schaalia odontolytica previously known as Actinomyces odontolyticus remain uncommon. This is a case report of a 6-year-old boy with a congenital heart disease (ventricular septal defect and pulmonary atresia) who presented with headaches, fever, neck stiffness and vomiting. Magnetic resonance imaging of the brain showed central T1W hypointense, T2/FLAIR hyperintense collection in the dilated left lateral ventricle with associated periventricular vasogenic oedema indicating a primary intraventricular abscess. The main abscess was drained via a burr hole with persistent small abscesses in the occipital and temporal horns. A second burr hole attempt at draining the occipital and temporal lobe abscesses failed. Cultures of the pus yielded Schaalia odontolytica a known flora of the mouth . No oral lesions were observed in the patient. The patient was managed on 61 days of amoxicillin-clavulanic acid, with erythrocyte sedimentation rate falling from 6 mm/h to 1 mm/h after 2 months of therapy. Primary intraventricular abscess is a rare but potentially life-threatening condition that can present with nonspecific neurological symptoms. In children with cyanotic congenital heart disease, an intracranial abscess should be considered when compatible clinical and neuroimaging findings are present. This case highlights the importance of MRI for diagnosis and microbiological examination of drained material for identification of unusual pathogens such as Schaalia odontolytica .