Nasal trigeminal sensitivity after total laryngectomy: A psychophysical study.

OBJECTIVES: Total laryngectomy permanently diverts respiratory airflow through a tracheostoma, abolishing nasal breathing. Although olfactory loss is well described, it remains unclear whether nasal trigeminal chemosensation is perceptually accessible under natural airflow-deprived conditions. We aimed to assess trigeminal performance after total laryngectomy under both airflow-assisted (menthol lateralization detection threshold [LDT]) and non-assisted conditions. MATERIAL AND METHODS: A prospective cross-sectional study assessed trigeminal function in patients undergoing total laryngectomy (n=1 preoperative; n=3 postoperative) and matched healthy volunteers (n=10). Trigeminal sensitivity was evaluated using a menthol LDT protocol and the trigeminal subscale of the Barcelona Smell Test-24 (BAST-24), alongside several patient-reported outcome measures. RESULTS: Controls and the preoperative reference showed preserved trigeminal function (mean LDT 16.1±1.9; BAST-24 trigeminal 92.5±8.0%). Postoperative patients exhibited markedly elevated menthol thresholds (mean LDT 3.3±1.1), and trigeminal identification on BAST-24 was 0% in all three cases. Gustatory scores were preserved (100%) in all participants. CONCLUSION: One month after total laryngectomy, nasal trigeminal chemosensation appears poorly accessible under naturalistic airflow-deprived conditions, with a pronounced elevation of menthol lateralization thresholds and abolition of sniffing-dependent trigeminal identification. Notably, this deficit persists even when airflow is mechanically assisted, suggesting a sensory down-regulation beyond mere physical transport failure. These preliminary findings support further longitudinal studies assessing whether airflow-inducing rehabilitation may restore trigeminal perceptual availability.