The Nasal Dysfunction Clinic is unique in that it has available a variety of sophisticated tests to evaluate nasal dysfunction.
The standard smell test is conducted in two different ways. The first is a threshold test which measures an individual´s ability to detect various concentrations of a single odor. This is similar to a hearing test or to an eye test in that it measures that organ´s ability to perform correctly. The second part of the smell test is an odor identification test. The patient will be presented ten different odors and asked to identify them. Based on one´s performance on the threshold tests and the odor identification tests, a score is calculated. A separate score is calculated for the right and left sides of the nose. A perfect score would be 100. A score from 0–10 is considered anosmia; from 10–40 severely hyposmic; 40–60 moderately hyposmic; 60–90 mildly hyposmic; 90–100 is considered normal.
- A simple smell test called the alcohol sniff test (AST) is often used for olfactory screening and can be used at home.
- Another smell test is the University of Pennsylvania Smell Identification Test. This is referred to as the UPSIT.
The sense of taste can also be tested. First, the patient is asked to identify a series of four different concentrations of salty, sweet, sour, and bitter tastes which we call stimuli. Next, the patient is asked to estimate the strength of the taste stimuli by assigning numbers. In order to compare the estimates given by one individual to those of others, a second sense (hearing) is used. Five levels of loudness of a single tone are interspersed with the taste stimuli, and intensity estimates are also assigned to the sounds. The patient then compares the intensity of the taste to the intensity of the sound. If a patient rates the tastes as much weaker than the sounds where other people would rate them as equally strong, then the test demonstrates a diminished sense of taste in that patient.
Rhinomanometry measures an individual´s ability to breathe through the nose. This is done by placing a sealed system in the right and left nostril independently and asking the individual to breathe in and then to breathe out. The volume and rate of airflow and the pressure required to generate this airflow is measured. The result is calculated as a resistance to air flow. Resistance then is a measure of the degree of nasal obstruction; the higher the resistance, the greater the obstruction. Generally speaking, results of five or less are considered normal and above five are abnormal. The rhinomanometry is performed first with the nose in its normal state and then after the mucosa is decongested with a medicine called Neosynephrine. After the Neosynephrine has taken effect, the rhinomanometry is repeated. The resistance in the decongested state should be an indicator of the degree of structural or anatomical obstruction.
The nose cleans itself by transporting trapped particles and mucous to the back of your nose. The tissue in your nose responsible for moving the mucous blanket are the cilia. Ciliary motility is measured by placing a small tablet of saccharin on a mucous membrane in the front of your nose. This is normally transported to the back of your nose in a period of fifteen to twenty minutes. You know it reaches the back of your nose when it drains down the back of your throat, at which time you detect the saccharin as a sweet taste. The time it takes for the saccharin to first be tasted is a measure of ciliary motility.
Cilia ultrastructure and function examines the architecture and performance of nasal respiratory cilia. Cilia are the small (microscopic) hairs lining the superficial nasal mucosa, and are necessary for cleaning the nasal cavity. This test is not done routinely; however, under certain specified conditions it may be required.
The nose can be examined with a light and a nasal speculum but this only gives the physician a view of the front part of the nose. If one wishes to study the nose carefully, one needs to examine more deeply and this is done by inserting a steel-coated glass rod through the front of the nose and looking directly at the normal nasal structures. Nasal endoscopy is the only means of examining the olfactory epithelium and can be extremely useful in differentiating congenital and traumatic anosmia from viral anosmia and from other conditions. It is often useful for identifying nasal tumors, particularly polyps arising high within the nasal cavity.
The x-ray examination is important for looking at the paranasal sinuses, for looking for intranasal tumors, and for looking for brain tumors. The traditional x-ray has been a sinus series; however, this is a very gross test and often inaccurate. A much more sensitive examination is achieved with a computerized tomographic scan, most commonly abbreviated CT or CAT scan. Finances permitting, this will be requested for most individuals and is generally a very useful diagnostic test. A normal CT scan is shown on the following page. Two normal and three abnormal scans are shown at left.
Skin tests are performed by placing small amounts of materials commonly inhaled or eaten on the skin, and then pricking the skin gently with a small needle. After fifteen to twenty minutes a red, raised, itchy spot is present at the site of material which may be causing allergic symptoms. This test must be compared to the seasonal and environmental pattern of nasal dysfunction before conclusions regarding allergy can be made. If the test is positive, avoidance of the material causing the allergy, if possible, is helpful. In addition, desensitization (allergy shots) may also be recommended. Allergy can now be measured with a blood test. The IgE is the immunoglobulin involved with allergy. Measuring the IgE level in the blood is a good indicator of allergic propensity.
Immunoglobulin deficiencies, specifically secretory IgA deficiency, can be a part of recurrent or persistent infection. Serum antibody levels are measured from your blood and hence may be requested at the same time as the IgE is being requested.