A Prefrontal Neuromodulation Route for Post-Traumatic Olfactory Dysfunction: A Perspective Supported by Recovery During Left-DLPFC rTMS

Post-traumatic olfactory dysfunction (PTOD) is a common and often persistent sequela of mild traumatic brain injury (mTBI), with limited evidence-based treatment options. We propose that high-frequency rTMS applied to the left dorsolateral prefrontal cortex (DLPFC) may support olfactory recovery via top-down modulation of distributed olfactory, attentional, and reward networks, and we outline key mechanistic and methodological considerations for future studies. We summarize the case of a 70-year-old woman with severe post-traumatic hyposmia persisting for ~5 months, who underwent a 12-week, 10 Hz rTMS course over left DLPFC (36 sessions; 800 pulses/session). Using a structured door diary and repeated ratings across odour categories, she reported stepwise improvement starting around sessions 10–12 (re-emergence of pungent odours) and progressing to broad restoration, including subtle fragrances, by treatment end; no adverse events occurred. While causality cannot be inferred from a single case, this pattern is consistent with a network-level neuromodulatory effect and motivates controlled trials combining standardized olfactory testing with neurophysiology and neuroimaging.