267. Therapeutic Management of Bacterial Brain Abscess: An Overview of Diagnosis and Outcomes

Abstract Background We describe and compare the clinical, diagnostic evaluation and outcomes of patients who underwent therapeutic management for pyogenic brain abscess. Methods We retrospectively reviewed adults who presented with pyogenic brain abscess from January 1, 2009 through June 30, 2020. Results 231 patients were identified during the study period. Sixty-one (26.4%) patients received antibiotic therapy alone, and 170 (73.6%) had a combination of antibiotic therapy and surgical intervention. The median age for the medical and combined therapy group was 59 years and 58 years, respectively. Patients who received medical treatment had a higher prevalence of infective endocarditis than those who received combined therapy (6.6% vs. 0.6%; P=0.005). The medical therapy group was more likely to have brain MRI and cranial CT than the patients with combined therapy (75.4% vs. 63.5%; P=0.041). Midline shift (11.5% vs. 31.2%; P=0.002), a single (21% vs. 83%; P=0.001) and greater size (1.4 cm vs. 2.5 cm; P=0.007) brain abscess was significant when comparing medical vs. surgically managed abscess. Stereotactic surgical technique was the preferred diagnostic approach for the medical group (65.6% vs. 46.5%; P=0.010), and excision/craniotomy for the combined group (31.1% vs. 53.5%; P=0.002). Streptococcus viridans group was the predominant organism (32.8% and 25.9%; P=0.30). Compared to those who received combined therapy, patients with medical therapy alone were most likely to receive cephalosporin (72.1% vs. 41.2%; P=< 0.0001), vancomycin (23% vs. 12.4%; P=0.047) and metronidazole (27.9% vs. 14.7%; P=0.022). In both groups, median duration of antimicrobial therapy was 42 days (P=0.12). Patients with medical therapy alone had a higher mortality rate (18% vs. 7.1%; p=0.014) but less neurologic sequelae (21.3% vs. 30.6%; P=0.16) compared with combined therapy. Medical Management. Organism isolated in the medical management group Combined Management. Organism isolated in the combined management group Demographic and Clinical Characteristics of Patients with Brain Abscess who Underwent Therapeutic Management Conclusion Most patients with pyogenic brain abscess had no identified risk factors, and brain MRI and cranial CT were the diagnostic imaging modalities of choice. Compared to those who received medical therapy alone, patients with combined treatment had a single and greater size fluid collection with the presence of midline shift. A prompt combined surgical and medical approach with prolonged antimicrobial therapy can cure the infection. Outcomes of Patients with Bacterial Brain Abscess Radiologic and Surgical Diagnosis of Patient with Brain Abscess who Underwent Therapeutic Management Disclosures John C. O’Horo, Sr., MD, MPH, Bates College and Elsevier Inc (Consultant) M. Rizwan Sohail, MD, Medtronic Inc., Philips, and Aziyo Biologics, Inc (Consultant) M. Rizwan Sohail, MD, Aziyo Biologics (Individual(s) Involved: Self): Consultant; Philips (Individual(s) Involved: Self): Consultant

Conclusion. Patient's occupation played a pivotal role in establishing diagnosis. In RMSF, IgM and IgG antibodies appear 7 to 10 days after the onset of the illness, and a fourfold rise in IgG is diagnostic of seroconversion and recent illness. Patient's waxing and waning symptoms, persisting for weeks and remarkable response to doxycycline, are typical features of RMSF encephalitis.
Disclosures. Background. Human Herpesvirus-6 (HHV-6) seroprevalence rates in the United States range from 72-95%, but clinical illness in the adult population is extremely rare, which often presents as meningoencephalitis in immunocompromised hosts. The literature on HHV-6 encephalitis in immunocompetent adults is limited to a select number of case reports, ultimately providing scant treatment guidance for clinicians.
Methods. This is a unique case describing the clinical course of confirmed HHV-6 encephalitis in an immunocompetent host.
Results. The patient is a 77-year-old immunocompetent female presenting with two days of global aphasia and increased muscle tone. She presented hypertensive with a leukocytosis. Work-up for acute stroke was unremarkable, but lumbar puncture revealed an elevated white blood cell (WBC) count of 39 leukocytes/mm 3 with a lymphocytic predominance. BioFire FilmArray® Meningitis/Encephalitis panel (FAME) demonstrated positivity for HHV-6 with a viral load of 8,500 copies/mL in the cerebrospinal fluid (CSF) and 4.1 million copies/mL in serum. The patient experienced temporary improvement in her aphasia after being initiated on intravenous (IV) ganciclovir for 12 days. Shortly after the initiation of therapy, her aphasia worsened with repeat CSF studies demonstrating an increased viral load to 35,700 copies/mL. She was subsequently transitioned to IV foscarnet for HHV-6B coverage and discharged after completing 21 days of therapy with marked improvement in her symptoms. Two weeks later, the patient was readmitted for recurrence of aphasia. MRI brain at that time was unremarkable with repeat lumbar puncture demonstrating a WBC count of 8 with 113 copies/mL of HHV-6. Serum levels were also elevated to 4.7 million c/mL. The patient was restarted on foscarnet but continued to deteriorate clinically. She ultimately experienced multiple seizure-like episodes resulting in a noncommunicative, somnolent state. She was transitioned to hospice care and passed away 2 days after discharge.
Conclusion. Despite the use of recommended medical therapies, the mortality and clinical progression of HHV-6 in immunocompetent adults is still unpredictable. Further studies are needed in this population to provide guidance for clinicians.
Disclosures. All Authors: No reported disclosures combined therapy (6.6% vs. 0.6%; P=0.005). The medical therapy group was more likely to have brain MRI and cranial CT than the patients with combined therapy (75.4% vs. 63.5%; P=0.041 Conclusion. Most patients with pyogenic brain abscess had no identified risk factors, and brain MRI and cranial CT were the diagnostic imaging modalities of choice. Compared to those who received medical therapy alone, patients with combined treatment had a single and greater size fluid collection with the presence of midline shift. A prompt combined surgical and medical approach with prolonged antimicrobial therapy can cure the infection.

Outcomes of Patients with Bacterial Brain Abscess
Radiologic and Surgical Diagnosis of Patient with Brain Abscess who Underwent Therapeutic Management