Hyperbaric oxygen therapy for brain abscesses: A useful adjuvant treatment for a faster recovery

Brain abscesses are still characterized by substantial case fatality rates and a high risk of permanent functional impairment. Standard treatment consists of long-term antimicrobial therapy and various neurosurgical interventions. In a few institutions, hyperbaric oxygen therapy (HBOT) is used as an additional treatment modality. The purpose of this study was to evaluate the effects of adjuvant HBOT on neurological and radiological outcomes in patients with brain abscesses. 55 patients with brain abscesses treated at the Medical University Clinic of Graz between 2004 and 2022 were included in this retrospective analysis. Thirty patients (54.5%) received standard therapy, consisting of long-term antimicrobial therapy and at least one neurosurgical intervention. Twenty-five patients (45.5%) additionally underwent HBOT. After three months, 24% of patients in the HBOT group and 10% in the non-HBOT group exhibited no residual abscess or pathological enhancement; at six-month follow-up, the percentage increased to 80% in the HBOT group compared to 46.7% in the non-HBOT group (p = 0.009). At 12-month follow-up, a symptom-free status (modified Rankin Scale 0) was attained by 60% of HBOT group patients and 30% of non-HBOT group patients (p = 0.046). The 12-month mortality rates for HBOT and non-HBOT groups were 12% (n = 3) and 20% (n = 6), respectively. No adverse effects related to HBOT were noted. Adjuvant HBOT significantly improved radiological outcome after 6 months, neurological outcome after 12 months and reduced mortality. HBOT may be taken into consideration in all patients with brain abscesses, particularly in cases with deep seated or multiple lesions and when antimicrobial and surgical treatment had failed.