Objectives: There is no established treatment for chronic fatigue and various cognitive dysfunctions (brain fog) caused by long coronavirus disease 2019 (COVID-19). We aimed to clarify the effectiveness of repetitive transcranial magnetic stimulation (rTMS) for treating these symptoms.

Methods: High-frequency rTMS was applied to occipital and frontal lobes in 12 patients with chronic fatigue and cognitive dysfunction 3 months after severe acute respiratory syndrome coronavirus 2 infection. Before and after ten sessions of rTMS, Brief Fatigue Inventory (BFI), Apathy Scale (AS), and Wechsler Adult Intelligence Scale-fourth edition (WAIS4) were determined and N-isopropyl-p-[¹²³I]iodoamphetamine single photon emission computed tomography (SPECT) was performed.

Results: Twelve subjects completed ten sessions of rTMS without adverse events. The mean age of the subjects was 44.3 ± 10.7 years, and the mean duration of illness was 202.4 ± 114.5 days. BFI, which was 5.7 ± 2.3 before the intervention, decreased significantly to 1.9 ± 1.8 after the intervention. The AS was significantly decreased after the intervention from 19.2 ± 8.7 to 10.3 ± 7.2. All WAIS4 sub-items were significantly improved after rTMS intervention, and the full-scale intelligence quotient increased from 94.6 ± 10.9 to 104.4 ± 13.0. Hypoperfusion in the bilateral occipital and frontal lobes observed on SPECT improved in extent and severity after ten sessions of rTMS.

Conclusions: Although we are still in the early stages of exploring the effects of rTMS, the procedure has the potential for use as a new non-invasive treatment for the symptoms of long COVID.