A Prefrontal Neuromodulation Route for Post-Traumatic Olfactory Dysfunction: A Perspective Supported by Recovery...

Area of Science:

• Neuroscience
• Neurology
• Otolaryngology

Background:

• Post-traumatic olfactory dysfunction (PTOD) is a frequent and enduring consequence of mild traumatic brain injury (mTBI).
• Current evidence-based treatment options for PTOD are limited.
• Neuromodulatory interventions are being explored for neurological recovery.

Purpose of the Study:

• To investigate the potential of high-frequency repetitive transcranial magnetic stimulation (rTMS) applied to the left dorsolateral prefrontal cortex (DLPFC) for treating PTOD.
• To explore the mechanistic pathways, including top-down modulation of olfactory, attentional, and reward networks, through which rTMS might facilitate olfactory recovery.
• To outline key mechanistic and methodological considerations for future research in this area.

Main Methods:

• A case study of a 70-year-old woman with severe post-traumatic hyposmia lasting approximately 5 months.
• Treatment involved a 12-week course of 10 Hz rTMS over the left DLPFC, comprising 36 sessions with 800 pulses per session.
• Olfactory function was assessed using a structured diary and repeated ratings across different odour categories.

Main Results:

• The patient reported a stepwise improvement in olfactory function starting around sessions 10-12, with the re-emergence of pungent odours.
• By the end of the 12-week treatment, broad olfactory restoration was observed, including the ability to perceive subtle fragrances.
• No adverse events were reported during the rTMS treatment course.

Conclusions:

• This case suggests that high-frequency rTMS over the left DLPFC may be a viable therapeutic approach for post-traumatic olfactory dysfunction.
• The observed olfactory recovery pattern is consistent with a network-level neuromodulatory effect.
• Controlled trials combining standardized olfactory testing with neurophysiological and neuroimaging techniques are warranted to establish causality and further elucidate mechanisms.