(Kiosk 4) Delayed-onset Streptococcus Intermedius Brain Abscess After Dental Procedure: A Case Report

Case Diagnosis: Streptococcus intermedius brain abscess and ventriculitis diagnosed months after dental procedure.

Case Description or Program Description: 68-year-old male with history of squamous cell carcinoma of the mouth status post palliative chemotherapy and radiation (last treatment approximately one month prior to IPR admission), presented to a local ER one week after onset of visual complaints and headache followed by an episode of unresponsiveness. No documented fevers or seizure activity. Notably, this patient had significant periodontal disease with tooth extractions three months earlier. MRI revealed a large parieto-occipital abscess. Subsequent neurosurgical evacuation identified S intermedius as the causative organism. Parenteral antibiotics were initiated prior to transfer to acute inpatient rehabilitation.

Setting: Acute Inpatient Rehabilitation Hospital

Assessment/Results: Upon acute inpatient rehabilitation admission, deficits included left-sided weakness with hemi-neglect, left visual field scotoma, dysphonia, and disorientation. These compounded residual mild dysarthria and dysphagia related to his oropharyngeal carcinoma. He demonstrated remarkable functional improvements. Mobility progressed to ambulation with a four-wheeled walker. Orientation improved to >28/30 on the O-log. Visual field deficit persisted but left-sided neglect significantly improved facilitating return home with assistance.

Discussion (relevance): Brain abscess most commonly results from infection with Staphylococcus or Streptococcus species. Streptococcus intermedius is implicated when the source is thought to be from the oral cavity. The most common location for brain abscesses tends to be fronto-temporal. An occipital presentation, as seen in our patient, is rare. Predisposing factors for intracranial location of the abscess include trauma, hematogenous spread, and associated contiguous focus of infection. The classic triad of headache, fever, and focal neurologic deficits may only be present in 20% of patients. Intravenous antimicrobial therapy and evacuation remain the criterion-standard treatment.

Conclusions: Brain abscess should be considered on the differential diagnosis in patients with profound, rapid neurologic decline particularly in those subsets of patients with significant periodontal disease. Rapid identification and treatment with neurosurgical intervention and antimicrobial therapy followed by intensive rehabilitation optimizes functional neurological recovery.