Cerebellar Abscess Caused by Rare Bacteria: A Case Report.

Rothia dentocariosa and Streptococcus intermedius are bacteria of the normal upper respiratory tract flora. To our knowledge, only 3 cases of a brain abscess due to R. dentocariosa have been reported. We present a 66-year-old man with a cerebellar abscess due to R. dentocariosa and S. intermedius. The patient had a gradual worsening of dizziness with imbalance and binocular diplopia during the 3 days before admission. Abnormal findings from the neurological examination were horizontal and circular positional nystagmus on right and left gaze, torsional vertical nystagmus on downward gaze, skew deviation with a slightly hypertropic right eye with cover-uncover correction, a slightly smaller right palpebral fissure, mild right limb ataxia in the upper (more than the lower) limbs, dysdiadochokinesia in the left upper limb, and dysmetria in the right lower limb. Magnetic resonance imaging showed a spherical lesion in the right cerebellar lobe with large surrounding edema. On the third day after admission, his temperature increased, and he had nausea and a delusional episode. A repeat computed tomography of the brain scan showed an increase in the surrounding edema. The patient underwent unilateral suboccipital craniectomy with drainage of the lesion. Based on culture results, the diagnosis was an abscess due to R. dentocariosa and S. intermedius. No source of infection was found. After surgery and a course of intravenous antibiotics, the patient's symptoms gradually improved. In conclusion, this is a rare case of a cerebellar abscess due to R. dentocariosa and S. intermedius.