Anthony L. Komaroff, MD, reviewing Zilberman-Itskovich S et al. Sci Rep 2022 Jul 12

This article is courtesy of the NEJM Journal Watch.

Hygiene and Protection SuppliesIn a randomized trial, 8 weeks of treatment were associated with improvement in cognition, mood, fatigue, and pain.

Hyperbaric oxygen has a checkered history as a therapy for various disorders, due to studies that were small and poorly controlled. A new randomized, double-blind, sham-controlled trial from Israel suggests it might be useful in people with persisting impaired cognition, fatigue, and pain for at least 3 months after acute COVID-19 (i.e., “long COVID”).

Hyperbaric oxygen therapy or a sham procedure were given to 73 long-COVID patients for 5 days weekly for 8 weeks. Participants were asked to guess if they had been given hyperbaric oxygen therapy or sham: Participants in either arm were unable to guess correctly. Symptom questionnaires, formal cognition testing, and magnetic resonance imaging (MRI) studies of the brain were performed pretreatment and at 1 to 3 weeks posttreatment. Pretreatment, the results of these measurements were not different in the two groups. Posttreatment, however, the hyperbaric oxygen therapy group had significantly better cognitive function, less fatigue, less pain, and fewer complaints of mood disorders than the sham group. In the oxygen group, MRI studies showed superior brain perfusion and some microstructural differences that indicated improved neuroplasticity — differences that correlated with clinical improvement.


This provocative report is well-controlled and shows objective improvements in the brain that correlate with symptom improvement. For this reason, the report surely will lead other groups to try to confirm these findings. If hyperbaric oxygen therapy is judged to be effective, the optimal duration of therapy must be defined. Whether the benefit is sufficient to justify the time and expense also remains to be determined.