Comparison of subjective perception with objective measurement of olfaction.

OBJECTIVE: To see if nasal peak inspiratory flow rate and subjective sense of smell had any correlation with olfactory thresholds. STUDY DESIGN AND SETTING: A cohort study of 186 normal volunteers was recruited from among staff and visitors at a university hospital. Olfactory thresholds were detected for each subject (103 with eucalyptol and 83 with phenethyl alcohol), along with nasal peak inspiratory flow (PIFR). Subjective sense of smell, along with nasal symptoms, mood, and alertness, were recorded on visual analogue scores. RESULTS: Subjective perception of smell had no correlation with olfactory thresholds detected (P = 0.4057) and the other subjective measures also had no correlation. There was a significant relationship of PIFR to thresholds in the group tested with phenethyl alcohol (P = 0.002). CONCLUSION: As with the sensation of nasal patency, the self-assessment of a subject's sense of smell has poor correlation with their actual olfactory ability. SIGNIFICANCE: A patient's history cannot be relied upon when determining their olfactory ability and formal testing should be performed. EBM rating: A-1b.     

Olfactory detection thresholds using pyridine, thiophene, and phenethyl alcohol

An objective examination of olfactory function is needed for evaluation and clinical progression of patients with olfactory deficits. Two hundred sixty-eight healthy subjects were studied in order to establish olfactory thresholds for three test odorants. Subjects were required to simply detect the presence of an odor when comparing various log dilutions of test odorant against two "blank flasks. These data have provided a means of quantitating existing olfactory deficits in affected patients. Olfactory function was found to be diminished in elderly subjects and should be considered a factor when evaluating older patients.     

Intranasal challenge with aspirin in the diagnosis of aspirin intolerant asthma: evaluation of nasal response by acoustic rhinometry

BACKGROUND: Nasal provocation tests with lysine-aspirin have recently been introduced for assessment of aspirin intolerant asthma. A study was undertaken to evaluate the usefulness of acoustic rhinometry, a new non-invasive technique, in the diagnosis of aspirin intolerant asthma/rhinitis. METHODS: Fifteen patients with aspirin intolerant asthma/rhinitis (nine women, mean (SD) age 54.7 (14) years), eight patients with aspirin tolerant asthma/rhinitis (three women, mean (SD) age 52.6 (7.8) years), and eight healthy subjects (two women, mean (SD) age 32.5 (9.7) years) were studied. All subjects were challenged with saline (0.9% NaCl) and 25 mg lysine acetylsalicylic acid (L-ASA) instilled into each nostril of the nose on two separate days. The clinical response was evaluated based on nasal symptoms (sneezes, itching, secretion and blockage). The nasal response was measured by acoustic rhinometry. Symptoms and rhinometry curves were recorded at 10 minute intervals for three hours, one hour before challenge and two hours after challenge. RESULTS: L-ASA challenge induced a significant increase in symptoms in patients with aspirin intolerant asthma/rhinitis. No differences in the clinical response were detected in those with aspirin tolerant asthma/rhinitis or healthy subjects. L-ASA challenge induced a significant decrease in nasal volume measured by acoustic rhinometry in aspirin intolerant patients. No differences were detected between the challenges in aspirin tolerant patients. If a 25% decrease in nasal volume is taken as the cut off point, the specificity of the test was 94% and the sensitivity reached 73%. The nasal challenge was well tolerated by all subjects. CONCLUSION: Acoustic rhinometry may be used to study the nasal response to L-ASA. Nasal challenge with L-ASA is safe and can be used as a diagnostic test even in asthmatic patients with severe bronchial obstruction.     

Altered activation patterns within the olfactory network in Parkinson's disease

Olfactory impairment is a consistent premotor symptom in sporadic Parkinson's disease (PD), presumably caused by pathological processes in the olfactory bulb and olfactory structures within mesolimbic brain areas. The objective of the present study was to obtain an in-depth insight into olfactory network dysfunction in PD patients. Event-related functional magnetic resonance imaging (3 T) was conducted with 16 early-stage PD patients and 16 matched controls during an odor detection task. Activation within the olfactory network was analyzed both in terms of strength of activation (whole-brain random effects, regions of interest [ROI] analysis based on the hemodynamic response function) as well as time-course characteristics (finite impulse response-based ROI analysis). Olfactory-induced activation in patients with PD in comparison to a standard activation pattern obtained from controls revealed profound hyperactivation in piriform and orbitofrontal cortices. However, whereas orbitofrontal areas seem to be unable to discriminate between signal and noise, primary olfactory cortex shows preserved discriminatory ability. These results support a complex network dysfunction that exceeds structural pathology observed in the olfactory bulb and mesolimbic cortices and thus demonstrate the important contribution of functional data to describe network dynamics occurring in the degenerating brain.     

Outcomes of septoplasty.

A prospective nonrandomized study of consecutive patients presenting to the Massachusetts Eye and Ear Infirmary for septoplasty was conducted to evaluate patient-based outcome. Patients received statistically validated measures of general health status (Short Form-12) and nasal specific health (Nasal Health Survey) before and 6 and 12 months after surgery. Multiple perioperative patient- and surgeon-dependent treatment variables were also evaluated to determine the impact on outcome. A total of 161 patients were entered into the study, and 93 were available for statistical analysis. At 9 months the mean follow-up (range 6-12 months), both symptom and medication subscores of the Nasal Health Survey, and the total score demonstrated significant improvement (P < 0.05); 71% of patients had clinically significant improvement as determined by at least a 50% decrease in duration of nasal symptoms. Measures of general health did not differ significantly from normative values at baseline and did not change after surgical intervention. Predictor analysis revealed that female gender and a history of previous nasal surgery predicted worse outcome.     

Olfactory dysfunction in cystic fibrosis: Impact of CFTR modulator therapy

BackgroundElexacaftor-tezacaftor-ivacaftor (ETI) improves pulmonary health and chronic rhinosinusitis (CRS) for people with cystic fibrosis (PwCF), however its impact on olfaction has not been investigated. Olfactory dysfunction impairs quality-of-life (QOL). This study evaluated the impact of ETI on multiple olfactory metrics.MethodsAdult PwCF/CRS with CF transmembrane conductance regulator genotype F508del/F508del or F508del/minimal function who clinically initiated ETI participated in a prospective, observational study. Endpoints included changes after 6 months of ETI in quantitative olfactory function (Smell Identification Test, SIT), olfactory QOL (Questionnaire of Olfactory Disorders, QOD) and percent olfactory cleft opacification (%OCO), representing superior nasal cavity inflammation where afferent olfactory neurons are concentrated.Results30 PwCF/CRS met inclusion criteria; 25 completed the study. Mean ETI adherence was 93%. At baseline, participants were hyposmic (mean SIT 31.3), had significant %OCO (mean 65.6%), yet reported non-impaired olfactory QOL (mean QOD 6.1). At follow-up, mean SIT worsened mildly (p=0.009), mean %OCO remained stable (p=0.46), and mean QOD improved modestly (p=0.008). No outcomes were impacted by prior modulator use, genotype, nasal polyps, or CF-related diabetes. Prior sinus surgery was associated with QOD improvement (p=0.04). Increased (worse) baseline QOD scores and %OCO were associated with greater improvements (p<0.003), but not SIT (p=0.44).ConclusionsETI was not associated with improvement in quantitative olfaction or olfactory cleft opacification after 6 months. PwCF/CRS have hyposmia but do not report impairment in olfactory QOL. Further study to investigate mechanisms explaining olfactory dysfunction and whether olfaction improves with greater duration of ETI or in younger age groups is warranted.     

Olfactory cleft disease: an analysis of 13 cases.

OBJECTIVES: Olfactory cleft disease was defined as (1) an olfactory disability related with a clinical and/or radiologic abnormality of the olfactory cleft and (2) a pathologic process limited to or predominating in the olfactory cleft. The objectives of this study were to describe the clinical and radiologic findings of this entity and to report the effect of medical therapy on the sense of smell. STUDY DESIGN AND SETTING: Thirteen patients with the criteria of olfactory cleft disease were included in this retrospective study. All patients had bilateral olfactory cleft abnormalities. A complete ENT examination with endoscopic evaluation and a computed tomography scan were performed in all cases. An olfactory threshold test was available in 12 cases before and after medical therapy, which included oral and topically administered steroid therapy. RESULTS: Olfactory disability was the major symptom of olfactory cleft disease. Other symptoms of chronic rhinosinus dysfunction was present in 75% of cases. Three pathologic processes were identified in patients with olfactory cleft disease: malformative, inflammatory, and inflammatory associated with anatomical deformities of olfactory cleft boundaries. Medical therapy was effective in lowering olfactory thresholds in 25% of the cases. CONCLUSIONS AND SIGNIFICANCE: Olfactory cleft disease involves various pathophysiologic processes. Computed tomography scanning provides the most information for diagnosis. Indications of functional endoscopic surgery remain to be defined after failure of medical therapy.     

Three-dimensional nasal morphology in cleft lip and palate operated adult patients

Nasal morphology was assessed three-dimensionally in 18 cleft lip and palate operated patients aged 19 to 27 years, and in 161 sex- and age-matched control subjects. Comparisons were performed by Student t and Watson-Williams' tests. No differences were found in nasal volume or surface. Nasal width, alar base width, and inferior width of the nostrils were significantly larger in male patients than in the reference men. The nasal bridge was shorter. Similar differences were found in the female patients. In addition, the right nostril was larger and the nasal height shorter. In men, the nasolabial and the nasal tip angles were smaller in the patients than in the reference subjects, whereas the facial convexity angle was larger in the patients. In conclusion, the nose of adult operated cleft lip and palate patients differed from that of normal control subjects. Surgical corrections of the cleft lip and palate failed to provide a completely normal appearance. The methods might be used to indicate where additional procedures might be performed to approximate a reference population.     

Nocturnal Olfactory Stimulation for Improvement of Sleep Quality in Patients With Posttraumatic Stress Disorder: A Randomized Exploratory Intervention Trial

Posttraumatic stress disorder (PTSD) is characterized by sleep impairment and nightmares. As pleasant odors presented during sleep affect the emotional tone of dreams without inducing arousal, we investigated whether sleep patterns in PTSD can be improved via nocturnal olfactory stimulation. Participants were 40 inpatients with PTSD (n = 35 women; age range: 20–59 years) who completed a randomized, patient‐blind, placebo‐controlled trial. Baseline measurement for 5 consecutive nights was followed by a 5‐night experimental intervention or placebo trial. During the intervention, patients received nocturnal stimulation with a pleasant odor (odor condition) or clean air (placebo condition) via an olfactometer that delivered inspiration‐triggered stimuli in a nasal tube or via an odorized nasal clip. After each night, the patients completed standardized questionnaires that assessed sleep parameters and dream content. Each night, sleep efficiency, sleep onset latency, and wakefulness after sleep onset were monitored with a motion biosensor. Baseline assessment revealed that PTSD severity was associated with poorer sleep outcomes. An interaction effect showed that nocturnal odorization affected dream intensity. Post hoc tests revealed an improvement in the group that used the nasal clip as compared to baseline, d = 0.68. No negative effects were observed after odorization with the nasal clip. Considering the limited sample size, the study indicates that nocturnal olfactory stimulation may serve as a low‐cost concomitant intervention to improve sleep quality in PTSD.     

Latex allergy at Groote Schuur Hospital--prevalence, clinical features and outcome.

BACKGROUND: The incidence of latex allergy is increasing worldwide but there is very little information available on the clinical outcome for affected individuals. OBJECTIVE: To determine the prevalence of latex allergy at Groote Schuur Hospital, a large teaching hospital in Cape Town, and to study the outcome for affected individuals. METHOD: Using a questionnaire, we screened 2,316 hospital workers for the presence of work-related symptoms. Workers who were symptomatic had Immunocap RAST (CAP RAST) or skin-prick tests to confirm latex sensitivity. Latex-avoidance measures were implemented in positive subjects. One hundred symptomatic, sensitised individuals were followed up 3 months after intervention to assess their clinical status. A further cohort of 25 individuals with ongoing nasal symptoms were studied in detail. RESULTS: Latex sensitisation was confirmed in 182 of 717 symptomatic workers (25.3%). Sensitised symptomatic workers were significantly more likely to have had a previous history of urticaria (P = < 0.001), oral allergy syndrome (P = < 0.001), or allergic conjunctivitis (P = 0.001), but not hay fever, perennial rhinitis, eczema or insect allergies. Latex sensitisation occurred among all classes of health care workers. Ocular and cutaneous symptoms were significantly associated with positive latex sensitisation (P = < 0.001). After latex intervention, ocular symptoms (P = < 0.001), skin rashes (P = < 0.001) and wheezing (P = 0.001) reduced significantly. Nasal symptoms did not improve. Undiagnosed and untreated underlying allergies to common aero-allergens were present in the majority of latex-sensitised patients with ongoing nasal symptomatology. CONCLUSION: The prevalence of symptomatic sensitisation to latex allergy at Groote Schuur Hospital is between 9.2 and 11.2%. Ocular and cutaneous symptoms are the most prevalent in sensitised workers, and unlike nasal symptoms are significantly reduced when latex-avoidance measures are introduced. Ongoing nasal symptoms after intervention is instituted are probably due to other allergic sensitivities in latex-sensitised health care workers.     

The office diagnosis of nasal and sinus disorders using rigid nasal endoscopy

Functional nasal endoscopic surgery has become increasingly popular because of the development of fiberoptic ridge nasal endoscopes. These same nasal endoscopes play an important role in the office diagnosis of nasal and sinus disorders. While not all physicians or medical institutions can afford the cost of nasal endoscopes for nasal sinus surgery, the cost of an office examination set is reasonable and the patient benefits are great. One hundred and fifty consecutive patients with nasal and/or sinus complaints and normal anterior rhinoscopic nasal speculum and posterior rhinoscopic nasopharyngeal examinations were each examined with rigid fiberoptic nasal endoscopy by two physicians to confirm each findings. Nasal endoscopy revealed fifty-eight (38.7%) patients with nasal pathology who had not been seen with traditional anterior and posterior rhinoscopic examination. The pathology found included obstructed natural maxillary sinus ostia and several pathologic disorders in the middle meatus, such as polyps and "synechiae". Many of these patients had seen several physicians and exhibited frustrating longstanding symptoms, some of which included postnasal catarrh, postnasal drainage, headache, facial pain, "sinus", pressure, and congestion. Nasal endoscopy can find nasal and sinus pathology that might easily be missed with routine speculum and nasopharyngeal examination. For patients with unexplained nasal sinus symptoms, the general otolaryngologist might consider rigid nasal endoscopic office examination as part of the routine office examination.     

Evaluation of olfactory nerve function after aneurysmal subarachnoid hemorrhage and clip occlusion

OBJECT: In this study, the olfactory nerve function (ONF) in patients with an aneurysmal subarachnoid hemorrhage (SAH) who underwent neurosurgical clip occlusion for intracranial aneurysm was assessed pre- and postoperatively. METHODS: In 13 patients with an aneurysmal SAH who underwent a frontobasal or frontotemporal neurosurgical procedure for clipping of a ruptured intracranial aneurysm, ONF was assessed pre- and postoperatively by using a standardized olfactory test battery ("Sniffin' Sticks"). Preoperative testing was performed within the first 72 hours after SAH. For their follow-up visit, patients were tested 3 months after surgery. Olfactory thresholds, odor discrimination, and odor identification were documented. Only cooperative patients were included, and as a result, all patients enrolled in the study were classified in Hunt and Hess Grade II. RESULTS: After SAH and before surgery, three patients were normosmic, seven were hyposmic, and three were anosmic according to the Sniffin' Sticks test. Thus, 10 of 13 patients with SAH already showed disturbance of ONF preoperatively. Of these 10, however, only two patients experienced reduced smell and taste sensation. At the 3-month follow-up review, 10 patients could be tested. Three normosmic patients remained normosmic. In one patient, ONF had improved from anosmic to hyposmic, whereas in another patient, ONF had worsened from hyposmic to anosmic. Thus, in eight patients, ONF remained unchanged after surgery. Three patients reported disturbed smell and/or taste sensation. One anosmic patient had experienced no smell sensation since surgery; however, he reported his taste to be normal. Another hyposmic patient experienced both reduced smell and taste sensation. One normosmic patient reported normal smelling ability but disturbed taste sensation. CONCLUSIONS: This study provides evidence that aneurysmal SAH causes disturbance of ONF in a substantial number of cases. With the exception of one case, neurosurgical treatment did not alter a preexisting olfactory deficit. Improvement of SAH-induced olfactory dysfunction at follow-up, however, can also be documented. The subjective assessments of the patients do not correspond well with the test battery results.     

Relationships between nasal obstruction, observed apnea, and daytime sleepiness.

OBJECTIVE: We administered a questionnaire survey to a working population in an attempt to clarify the relationships between self-reported nasal obstruction, observed apnea during sleep, and daytime sleepiness. STUDY DESIGN: A total of 7980 daytime workers were asked to complete questionnaires about nasal obstruction, apnea during sleep, and daytime sleepiness. Of the 7702 responses, the data from 4818 subjects were analyzed. Nasal obstruction and observed apnea were graded into 3 categories. Daytime sleepiness was assessed by the Epworth Sleepiness Scale. RESULTS: Subjects with chronic nasal obstruction had 5.22 and 2.17 times higher odds for having habitual observed apnea and excessive daytime sleepiness (EDS), respectively, compared with those without nasal obstruction (P < 0.001). After adjusting for 3 potential confounding factors (age, sex, and body mass index) and the presence of habitual observed apnea, odds ratios for having EDS decreased, but still remained significant. CONCLUSION: Nasal obstruction is likely to cause daytime sleepiness, at least in part, by causing sleep-disordered breathing including apnea during sleep.     

Triamcinolone acetonide aqueous nasal spray and fluticasone propionate are equally effective for relief of nasal symptoms in patients with seasonal allergic rhinitis.

OBJECTIVE: We compared 220 microg daily intranasal aqueous triamcinolone acetonide (TAA AQ) with 200 microg daily fluticasone propionate (FP) for relief of seasonal allergic rhinitis symptoms.Study design and setting Randomized, parallel-group, investigator-blind study included patients with symptomatic seasonal allergic rhinitis. After a baseline period, TAA AQ or FP was taken for about 21 days. Nasal symptom (discharge, stuffiness, itching, sneezing) severity was recorded twice daily; total nasal symptom score was calculated. Health-related quality of life was assessed by Rhinoconjunctivitis Quality of Life Questionnaire. RESULTS: Reductions in individual symptoms and total nasal symptom score were statistically significant versus baseline and were equivalent between treatments: -3.15 +/- 0.19 with TAA AQ (n = 148) and approximately 3.17 +/- 0.18 with FP (n = 147) (95% confidence interval for the difference, -0.7391 to 0.3693). Clinically and statistically significant improvements in Rhinoconjunctivitis Quality of Life Questionnaire scores were comparable. CONCLUSION: TAA AQ and FP were equally efficacious in relieving seasonal allergic rhinitis symptoms and improving health-related quality of life. SIGNIFICANCE: Differences in molecular potency of intranasal steroids do not confer differences in efficacy.     

Histamine release upon adenosine 5'-monophosphate (AMP) nasal provocation in allergic subjects

BACKGROUND: Nasal provocation with adenosine 5'-monophosphate (AMP) elicits nasal symptoms in subjects with rhinitis. Histamine released from mast cells may play a part in AMP induced nasal responses. METHODS: Symptoms of rhinitis were recorded and histamine release in the fluid obtained by nasal lavage after AMP, guanosine 5'-monophosphate (GMP), and placebo instillations was measured in nine subjects with allergic rhinitis and nine non-allergic controls in a double blind, randomised, placebo controlled study. RESULTS: No symptoms or significant increases in histamine were observed after GMP and placebo challenge. Significantly higher levels of histamine were seen in the nasal lavage fluids of allergic subjects following AMP challenge than in nonallergic controls, the median (range) histamine concentration increasing from the baseline value of 1.62 (0.44-6.99) ng/ml to 6.45 (0.81-16.17) ng/ml at three minutes. No increase in histamine levels was seen in the non-allergic subjects in whom the median histamine concentration was 1.13 (0.29-4.25) ng/ml at baseline and 0.97 (0.31-5.89) ng/ml three minutes after AMP challenge. CONCLUSIONS: AMP elicits an immediate rise in histamine levels in the nasal lavage fluid of allergic subjects compared with non-allergic individuals. These findings indicate that the exaggerated nasal response to adenosine may reflect mast cell priming in vivo, thus supporting its application as a potential new marker of allergic inflammation.     

Recovery of olfactory function after an anterior craniofacial approach

We assessed recovery of olfactory function in five consecutive patients who underwent surgical resection of midline skull base tumors using an anterior craniofacial approach in which the cribriform plate was mobilized with the dura. Olfactory function was evaluated before and after surgery using an intravenous olfactory test with prosultiamine and also a standard olfactory acuity test. Before surgery, one patient showed anosmia attributable to obstruction of the nasal cavity and olfactory cleft, and four patients showed normal olfactory function. After surgery, one patient was irreversibly anosmic, probably because of intradural dissection of the olfactory tracts. The other four patients, including the patient showing anosmia preoperatively, reported subjective recovery of olfaction 3 to 8 weeks after surgery. Intravenous and standard olfactory acuity tests indicated recovery of olfaction to the normal range in three patients and decreased olfactory function in one. With careful preservation of the olfactory system and of the integrity of the nasal cavity, olfactory function was found to recover after skull base resections via the anterior craniofacial approach.     

Recovery of Olfactory Function after an Anterior Craniofacial Approach

We assessed recovery of olfactory function in five consecutive patients who underwent surgical resection of midline skull base tumors using an anterior craniofacial approach in which the cribriform plate was mobilized with the dura. Olfactory function was evaluated before and after surgery using an intravenous olfactory test with prosultiamine and also a standard olfactory acuity test. Before surgery, one patient showed anosmia attributable to obstruction of the nasal cavity and olfactory cleft, and four patients showed normal olfactory function. After surgery, one patient was irreversibly anosmic, probably because of intradural dissection of the olfactory tracts. The other four patients, including the patient showing anosmia preoperatively, reported subjective recovery of olfaction 3 to 8 weeks after surgery. Intravenous and standard olfactory acuity tests indicated recovery of olfaction to the normal range in three patients and decreased olfactory function in one. With careful preservation of the olfactory system and of the integrity of the nasal cavity, olfactory function was found to recover after skull base resections via the anterior craniofacial approach.     

Olfaction preservation in anterior cranial base approaches: an anatomic study

OBJECTIVE: To study the anatomic basis for olfaction-sparing anterior cranial base approaches. METHODS: The medial anterior skull base containing the olfactory unit and delimited by the inner table of the frontal sinus, the lesser wing of the sphenoid bone, and the medial orbital walls was removed from six cadaveric specimens. Histological methods were used to investigate the location, distribution, and depth of penetration of olfactory nerves. Hematoxylin and eosin and Gomori trichrome staining were used to visualize landmarks and architecture. S-100 neurofilament protein immunostaining was used to identify nerve fascicles and axons. In three cadaveric head specimens, olfaction-sparing craniofacial approaches were performed and the excised olfactory units were evaluated histologically. RESULTS: Bundles of olfactory nerves were identified primarily in the nasal septum; relatively fewer bundles could be identified in the middle turbinate. Olfactory nerve endings were identified up to 20 mm below the cribriform plate (range, 7-20 mm). The superior and middle nasal meatus were most innervated; olfactory innervation was virtually absent in the inferior nasal meatus. Histological evaluation of the olfactory unit elevated during olfaction-sparing techniques routinely revealed transection of olfactory nerves that exited the skull base. CONCLUSION: In olfaction-sparing anterior cranial base approaches, the olfactory nerves are inevitably transected. The clinical significance of olfactory nerve transection for postoperative functional recovery of olfaction remains to be analyzed.     

EFFECTS OF SEDATION PRODUCED BY THIOPENTONE ON RESPONSES TO NASAL OCCLUSION IN FEMALE ADULTS

To test the hypothesis that full wakefulness is an importantfactor in the control of the route of breathing in adult humans,we have studied the responses to nasal occlusion before andduring sedation with thiopentone in 14 female subjects. A tightlyfitting partitioned face mask separated the nasal and oral breathingroutes. Nasal and oral breathing were identified from changesin carbon dioxide concentration and airway pressure in the differentcompartments of the face mask. Arterial oxygen saturation (S_po2)was monitored simultaneously. Eleven of 14 subjects breathedonly through the nose (nasal breathers) both before and duringsedation. In these subjects, the time required to initiate oralbreathing in response to nasal occlusion during sedation wassignificantly longer than that before sedation (mean 37.7 (SD15.5) s vs 3.2 (1.3) s(P <0.01)).Also, there was a significantdifference (P <0.01) in the smallest values of S_po2 attainedduring nasal occlusion before (98.0 (0.8) %) and after (89.3(4.3) %) sedation. In adult humans the ability to maintain adequateventilation by switching from the nasal to the oral route inresponse to nasal occlusion is greatly impaired during sedation,probably because of the impairment of conscious influence onthe control of the palatal muscles.     

Paradoxical nasal obstruction

Objectives: The majority of nasal surgery takes place with symptoms of unilateral or bilateral nasal obstruction. A large cohort of patients seen at the Nasal Airflow Laboratory at Prince of Wales Hospital (University of New South Wales) has been found to have normal physical examination, normal anterior rhinoscopy, normal nasendoscopy, and normal nasal airflow studies. This cohort has been considered to have the phenomenon of paradoxical nasal obstruction. The nasal cycle first described by Kayser in 1895 is the reciprocating cycle of congestion and decongestion alternating between the anterior nares, which is present in 80% to 100% of individuals having remarkably regular periodicity being affected by posture, exercise, and recumbency.Methods: This paper outlines their subsequent investigation by the use of extended symptom evaluation sheets, nasal airflow studies, and CT scans. The patients were randomized into 2 groups. Group A was treated with Alkalol (Taunton, MA) Nasal Spray and group B with low-dose self-administered capsaicin spray.Results: Of 1000 patients studied at the Nasal Airflow Laboratory, 27.5% were found to be complaining of significant symptoms of nasal obstruction with normal physical examination, anterior rhinoscopy, nasendoscopy, and airflow studies.Conclusions: The conclusions of the study were that paradoxical nasal obstruction occurs in about 25% of the population whose main symptom is nasal obstruction. Appropriate treatment for this subset is explanation of the physiology of their symptomatology and supramaximal stimulation of intranasal trigeminal nerve afferents.