THE NASAL CYCLE AFTER DEPRIVATION OF AIR-FLOW - A STUDY OF LARYNGECTOMY PATIENTS USING ACOUSTIC RHINOMETRY

Previous studies of the nasal cycle in laryngectomy patients using rhinomanometric techniques concluded that the cycle was abolished as a result of the cessation of airflow after laryngectomy. This study was performed with 20 postoperative laryngectomy patients (mean time after surgery 4 years, range: 2 weeks to 10 years) and 10 control subjects matched for age and sex (including 2 preoperative patients). Acoustic rhinometry was used to determine minimum nasal cross-sectional area and nasal cavity volume as the indices of nasal patency. Testing was repeated at intervals of 15-30 min over a period of 3-8 h. Fluctuations in nasal patency were observed in all laryngectomees and controls. The fluctuations were classified as 'classical' (reciprocal alternating) in 5 (25%) laryngectomees and 5 (50%) controls. An 'irregular' pattern of fluctuation was seen in 8 (40%) laryngectomees and 2 (20%) controls. An 'in concert' cyclical pattern was seen in 7 (35%) laryngectomees and 3 (30%) controls. This is the first demonstration of retention of the nasal cycle after airflow deprivation. Whilst the cycle may in some instances be modified after operation, it is not abolished. The central generation of the cycle is confirmed, although afferent input from airflow receptors may play a role in modulating the cycle's pattern and amplitude.