[Olfactory dysfunction due to nasal sinus disease. Causes, consequences, epidemiology, and therapy]

Olfaction not only contributes to our quality of life but, among other functions, it is also necessary for identifying potential dangers, e.g., fire or spoilt food. In general the value of olfaction is only recognized when the sense of smell is impaired or lost. Olfactory dysfunction is diagnosed according to its cause (e.g., sinonasal, post-traumatic, post-upper respiratory tract infection, neurodegenerative, and idiopathic). At present little is known about prognostic factors for predicting resolution of olfactory loss on an individual basis. In cases of impaired olfaction due to sinonasal disease, both conservative and operative treatments have been established. Corticoids are used both topically and systemically. In cases of severe mechanical obstructions or advanced stages of nasal polyposis, FESS (functional endoscopic sinus surgery) seems to be the state of the art.

Effects of radiotherapy on olfactory function

BACKGROUND AND PURPOSE

Changes in olfactory function have been reported in patients receiving significant doses of radiation to the olfactory epithelium. Aim of this study was to investigate severity and time course of changes in olfactory function in patients irradiated for tumours of the head and neck region.

MATERIAL AND METHODS

Forty-four patients receiving radiotherapy (RT) for tumours in the area of the head and neck participated (16 women, 28 men; age 11-81 y; mean 55 y). Olfactory function was measured before and bi-weekly during RT for 6 weeks. A subgroup (25 patients) was followed for 12 months. Patients were divided into two groups according to the dose to the olfactory epithelium. Twenty-two patients ('OLF group') had radiation doses to the olfactory epithelium between 23.7 and 79.5 Gy (median 62.2 Gy). In the 22 patients of the 'non-OLF group' the dose applied to the olfactory epithelium was significantly lower (2.9-11.1 Gy, median 5.9 Gy). Total tumour dose (30-76.8 Gy), age, sex distribution, and baseline chemosensory function were not significantly different between groups. Testing was performed for odour identification, odour discrimination, and olfactory thresholds.

RESULTS

Odour discrimination, but not odour identification or odour threshold, was significantly decreased 2-6 weeks after begin of therapy in the OLF group. In addition, a significant effect of the radiation dose was observed for odour discrimination. More than 6 months after therapy, OLF group patients had significantly lower odour identification scores compared to the non-OLF group.

CONCLUSION

As indicated through the non-significant change of olfactory thresholds, the olfactory epithelium is relatively resistant against effects of radiation. It is hypothesized that RT has additional effects on the olfactory bulb/orbitofrontal cortex responsible for the observed changes of suprathreshold olfactory function.

Gustatory function in chronic inflammatory middle ear diseases

HYPOTHESIS

Changes of gustatory function after ear surgery have been studied extensively. However, little is known on the influence of repeated/chronic inflammation within the middle ear on taste.

STUDY DESIGN

Prospective study.

MATERIALS AND METHODS

Forty-six patients suffering from either cholesteatoma (n = 25) or chronic otitis media mesotympanalis (n = 21) received quantitative gustatory tests. None of these patients had been operated on before these investigations.

RESULTS

Side by side comparison showed a significantly lower taste function on the anterior two thirds of the tongue ipsilateral to the site of inflammation, regardless of the diagnosis. Further analyses exhibited a trend toward greater impairment in relation to the severity of the inflammatory process.

CONCLUSION

These data are proof that taste function changes in relation to chronic middle ear diseases. It further shows that many of these alterations go unnoticed by the patients.

Extension of intracranial thrombosis after unilateral dissection of the internal jugular vein

OBJECTIVE

Resection of the internal jugular vein can be necessary in cases of radical neck dissection or even in cases involving benign neoplasms such as glomus tumors. According to the triad described by Virchow (ie, stasis of blood flow, damage to the endothelium, and changes in hemostasis), the development of a thrombosis in the venous vessels superior to the resected internal jugular vein seems to be possible. The aim of this study was to determine the extension of possible intracranial thrombosis after wound healing.

DESIGN

A total of 17 patients requiring resection of the internal jugular vein were evaluated prospectively using magnetic resonance imaging and 2-dimensional (time-of-flight) magnetic resonance angiography after the surgical treatment. Preoperative magnetic resonance images were obtained in all 17 patients for staging purposes as well as to exclude preoperative thrombosis of the internal jugular vein. Sixteen patients had malignant tumors, and 1 patient had a glomus tumor.

RESULTS

Intracranial thrombosis with thrombosis of the sigmoid sinus was found in 4 patients, and thrombosis of the transverse sinus was found in 3 patients. There were no complications such as intracranial hemorrhage or signs of increased intracranial pressure in any patients. There was no evidence of intracranial thrombosis in 10 cases. In these cases, thrombosis of the venous vessels superior to the resected vein ranged from none to complete thrombosis of the superior bulb of the internal jugular vein. After unilateral resection of the internal jugular vein, the venous blood leaves the brain mainly via the venous network of the contralateral side of the neck.

CONCLUSIONS

Although intracranial thrombosis of the sigmoid or transverse sinus seems to occur more frequently than was previously thought, intracranial complications such as venous infarction or increased intracranial pressure appear to be very rare. After unilateral radical neck dissection, the venous blood leaves the brain mainly via the venous system of the other side of the neck and the ipsilateral collateral veins.

Morphological and radiologic evaluation of the human nasopalatine duct

In several mammals, a direct connection between the nasal cavity and the oral cavity is a common finding. The structure is named the nasopalatine duct (NPD). It has been hypothesized to be functional in terms of transportation of odorants from the oral cavity to the nasal cavity. In humans, the NPD exists during embryological development. The connection between the nasopalatine infundibulum and the incisive fossa is typically closed at the time of birth. We present the case of a 24-year-old man who presented with a persistent NPD. By means of a thin, soft tube, it was possible to probe the NPD. Magnetic resonance imaging revealed a bony gap between the hard palate and the alveolar process of the maxillary bone with a length of 16 mm and a width of 6 mm. In light of the literature of the past 500 years, this represents a rare finding of a persistent NPD.

Prise en Charge Clinique des Dysosmies et Présentation du Test d'Olfaction Européen “Sniffin Sticks”: Une Revue

The medical community has neglected olfactory dysfunction for a long time. However, over the last two decades, remarkable progress has been made in terms of understanding the sense of smell and both the assessment and diagnosis of olfactory dysfunction. Currently, there are only a few validated olfactory tests. The most commonly used one is the University of Pennsylvania Smell Identification Test. Owing to its cultural biases, this test is mostly used in the United States. "Sniffin' Sticks" are one of the first European tests to be widely used. Since their development in 1996, they have been applied in numerous studies and have found increasing use in otolaryngology clinics. The goal of this article is to present Sniffin' Sticks and to provide a review of clinical olfactory research during recent years.

Assessment of olfactory function after septoplasty: a longitudinal study

AIM

Aim of the study was to evaluate septoplasty-related changes of lateralised olfactory function during both early and late postoperative periods in comparison to the preoperative situation.

MATERIAL/METHODS

Lateralised olfactory function was assessed in 30 patients using the "Sniffin' Sticks" test battery. Measurements were performed preoperatively, and 4 and 9 months postoperatively.

RESULTS

Prior to septal surgery measurements revealed significantly higher odor thresholds for the obstructed nostril compared to contralateral thresholds. No such observations were made for suprathreshold measures. Postoperatively, a significant decline of odor discrimination was found in comparison to the preoperative situation. However, there was no significant change of odor thresholds and odor identification function during the 9-month postoperative follow up. On an individual basis, one of the initially normosmic patients became hyposmic following surgery.

CONCLUSIONS

The present data indicate that odor thresholds, but not suprathreshold olfactory function, are related to nasal obstruction resulting from septal deviation. In contrast, postoperative changes were only seen for odor discrimination. Apart from psychological explanations of this finding, it may be hypothesized that these observations result from changes in intranasal airflow following surgery.

Change of voice characteristics during +3 Gz acceleration

BACKGROUND

This study was performed to test the feasibility of an experimental approach for assessing voice changes during exposure to increased +Gz acceleration. Such changes are probably due to mechanical alterations of the structures involved in voice production. This may be relevant to automatic speech analysis for flight control. Because voice control by means of auditory feedback may compensate for acceleration effects, the investigations included conditions with masked auditory feedback.

METHOD

Four male subjects read standard speech test material while seated in a human centrifuge both during sustained +3 Gz acceleration and in a reference condition. Both test runs were repeated with masking of the auditory feedback by a white noise presented via headphones. Microphone and acceleration signals were recorded on a PC-based dynamic signal acquisition board. Long-time average spectra (LTAS), fundamental frequency (F0), and the frequency of the first, second, and third formant (F1, F2, F3) of the vowels /a/, /o/, and /i/ were extracted from the microphone signal for the different conditions.

RESULTS

LTAS clearly differed between the masking conditions, but not between reference and +3 Gz conditions. F0 clearly rose with auditory masking and showed a small increase under +3 Gz acceleration. Several effects of +3 Gz acceleration on formant frequencies were found, all of rather small magnitude. Increased acceleration lowered F2 for the vowel /i/. A decrease of F3 was observed for vowels /i/ and /o/.

CONCLUSION

This pilot study has shown the feasibility of an experimental approach to assessing voice changes during exposure to increased +Gz acceleration. Exposure to +3 Gz showed small effects on FO and several formant frequencies. A definitive forthcoming study should assess the significance of these effects by investigating a greater number of subjects during exposure to acceleration higher than +3 Gz.

Optical measurement of nasal swellings

We introduce a new optical method to noninvasively and continuously measure the swelling process of the nasal mucosa whereby we use light of different wavelengths in the red and near-infrared range which is transilluminated through the nasal tissue and whose extinction is recorded as a function of time. From the temporal and spectral extinction data, we are able to extract characteristic parameters that describe the swelling process quantitatively by means of a regression-type parameter estimation algorithm. The method has been applied to the nasal allergen provocation test and verified on a limited number of volunteers.

Titanium Clip Prosthesis

OBJECTIVE

Prostheses for the reconstruction of a defective ossicular chain should be stable and firmly anchored to the ossicular remnants. This will prevent a defective connection from causing diminished sound transmission efficiency and will keep the prosthesis from tilting or even losing contact, which would result in a sound transmission block. Through temporal bone experimentation, we have consequently developed a very lightweight titanium prosthesis, which is fastened onto the stapes head with a clip mechanism.

METHODS

When temporal bone experiments using laser Doppler vibrometry confirmed that the prosthesis functioned well acoustically and when luxation experiments proved that it could be safely used without the risk of stapes dislocation, the prosthesis was used in a clinical application within an observational study. The University of Dresden Otorhinolaryngological Hospital as well as seven surgeons from five other hospitals participated in the study.

RESULTS

The results of 133 operations showed that, in over 90% of the cases, the prosthesis could be implemented without problems and with good mechanical stability. The first acoustical results obtained during the first year from 49 patients showed a sound transmission improvement range from 12 dB to 14 dB.

CONCLUSION

With the clip prosthesis, it seems possible to further improve defective middle ear function, which would allow the patient to regain social hearing after middle ear reconstruction. The reliability of the fastening is an innovation. Revision operations showed a stable prosthesis-stapes complex in the middle of a recurring cholesteatoma and the prosthesis could always be easily pulled from the stapedial suprastructure.

[Testing the sense of taste using validated procedures]

Psychophysical tests related to the sense of taste are usually less complex than those of the sense of smell. In addition to global tests a regional examination of the sense of taste might be indicated to search for nerve lesions. There are numerous validated psychophysical tests available based on the administration of liquid or solid substrates. The use of electrical currents (electrogustometry) is especially feasible for a rapid regional testing. The registration of gustatory event-related potentials to objectify results from psychophysical examination is possible although limited to a few centers world-wide.

[Testing the sense of smell using validated procedures]

There is a growing interest into the investigation of smell disorders in both research and clinical practice. For psychophysical ("subjective") investigations related to the sense of smell a variety of test kits are available, namely the various "Sniffin' Sticks" kits, the UPSIT (University of Pennsylvania Smell Identification Test) or the CCSIT (Cross-Cultural Smell Identification Test). Recording of olfactory evoked potentials (OEPs) and respiration olfactometry can be used for diagnosing smell dysfunctions in a more objective way.

[The human vomeronasal organ]

Odors influence human behavior. The perception of so-called pheromones is frequently mentioned in the context of a functional vomeronasal organ. Vomeronasal ducts can be detected in approximately half of the population. Its functionality, still a matter of debate, seems to be unlikely, at least after birth. It is easily conceivable that pheromone-induced changes in behavior are mediated through receptors in the human olfactory epithelium.