Assessment of Taste Function.

Taste disorders, impacting well-being and physical health, can be caused by many etiologies including the use of medication. Recently, taste disturbance is also considered as one of the predominant symptoms of COVID-19 although its pathogenesis requires further research. Localized taste disorders may be overlooked considering that whole-mouth taste perception is insured through several mechanisms. Individuals often fail to discern taste from flavor, and interviews/surveys are insufficient to properly assess taste function. Hence, various taste assessment methods have been developed. Among them, psychophysical methods are most widely applied in a clinical context. Less-biased electrophysiological, imaging, or morphological methods are used to a much lesser degree. Overall, more research is needed in the field of taste.

Taste perception in children with different caries activity.

PURPOSE: The aim of the study was to investigate whether caries-active and caries-free children differ in terms of their taste perception for sweet, sour, salty and bitter. METHODS: The study group consisted of 100 children aged 5-10 years: 50 caries-free children and 50 children with at least four untreated carious lesions. Taste perception was analysed using two test systems. First, filter paper strips impregnated with four taste qualities (sweet, sour, salty, and bitter) at four defined intensities were used ("taste strips"). Then a tasting spray in suprathreshold concentration of the respective taste was applied. The children were asked to name the perceived taste. The parents answered a questionnaire about the children's dietary habits. RESULTS: The children with high caries activity scored lower on average on the taste strips than the caries-free participants. For the taste sprays, the perception of the taste quality "bitter" was significantly worse in the children with caries than in caries-free children (Mann-Whitney U test p < 0.05). CONCLUSION: The results of this study suggest that taste preferences in children are associated with increased susceptibility to tooth decay.

Taste in dementing diseases and parkinsonism.

Like with many sensory abilities a reduction of taste and smell occurs during aging. Since there are hints to an additional reduction in dementing diseases, we assessed 52 patients, 26 women and 26 men, who were presented to a memory clinic, using the Sniffin' Sticks, Whole Mouth and Taste Strip Tests. While smoking, alcohol consumption, intake of drugs and sex exerted only minor impact, age and the severity of cognitive impairment were of major importance. There was a moderate but significant correlation between the severity of dementia, taste and smell, even if the age effect was partialled out. Notably, patients with Parkinson syndrome showed worse taste and smell abilities than those without. Here the differences were indeed marked enough to play a possible role in making the diagnosis. This exploratory study confirms a mild reduction of gustatory function in dementing diseases over and beyond that of normal aging which--in addition to a reduction of smell--seems to be especially marked in Parkinson syndromes.

Oral mucosal blood flow in patients with burning mouth syndrome.

The pathophysiology of burning mouth syndrome (BMS) is largely unknown. Thus, the aim was to study oral mucosal blood flow in BMS-patients using laser Doppler flowmetry (LDF). Thirteen BMS patients (11 female, two male; mean age+/-SD 64.3+/-7.9 years, mean disease duration 18.9+/-6.2 months) and 13 healthy non-smoking controls matched for age and gender (11 female, two male; mean age 64.7+/-8.1 years) were investigated. Using the LDF technique mucosal blood flow (mBF) was measured at the hard palate, the tip of the tongue, on the midline of the oral vestibule, and on the lip. Measurements were made at rest and over 2 min following dry ice application of 10 s duration using a pencil shaped apparatus. In addition, blood pressure (BP), heart rate (HR), peripheral cutaneous blood flow, and transcutaneous pCO(2) were continuously recorded. Mucosal blood flow (mBF) increased at all measurement sites in response to dry ice application (P<0.001) with peak flow at 0.5--1.5 min after stimulation onset. During the following 1.5--2 min, blood flow decreased at all sites with a tendency to return to baseline towards the end of the observation period. Except for BP and peripheral blood flow, all of the cardiovascular changes exhibited significant changes during the observation period; no differences between groups were detected. When compared to healthy controls BMS patients generally exhibited larger changes in mBF. These changes were significant for recordings made on the hard palate (F[1,24]=13.9, P<0.001). Dry ice stimulation appears to be an effective, non-invasive and reasonably tolerable means to investigate mucosal blood flow at different mucosal sites. In general, vasoreactivity in BMS patients was higher than in healthy controls. BMS patients exhibited a higher response on the hard palate compared to controls. These changes in oral blood flow appear to be specifically related to BMS symptoms indicating a disturbed vasoreactivity.

Assessment of gustatory function by means of tasting tablets.

OBJECTIVE: To develop a simple test for the screening of gustatory function in clinical settings. STUDY DESIGN: We tested 101 healthy volunteers (44 male and 57 female volunteers; mean age, 47 y) with the following gustatory test: the substances sucrose (sweet), citric acid (sour), sodium chloride (salty), and caffeine (bitter) were presented as tablets (diameter 4 mm) similar to common sweetener tablets. For quantitative assessment of whole-mouth gustatory function we used six different dosages with dilutions of each tastant in 50% steps. The highest dosage could be easily detected (sucrose, 30 mg; citric acid, 3 mg; sodium chloride, 2 mg; caffeine, 2 mg), and the lowest concentration was within threshold range. METHODS: Twenty-eight tablets (six different dosages of the four basic tastes plus four tasteless tablets) were tried in a randomized order. The entire test required 15 to 20 minutes. To evaluate the within-subject test-retest reliability, sessions were repeated after 1 week. Results were compared with those obtained by means of a conventional three-drop, forced-choice procedure using the method of ascending limits. RESULTS: Results of the new gustatory test were significantly correlated with those obtained using the three-drop, forced-choice procedure (correlation coefficient [r] = 0.66, P<.001). In general, women performed better than men. Furthermore, younger subjects exhibited a significantly higher gustatory sensitivity in both tests compared with older subjects. CONCLUSIONS: This quantitative test of whole-mouth gustatory function is easy to use, can be self-administered, requires little time, and has a long shelf-life. It appears to be suited for routine clinical assessment of gustatory function.

A test for the screening of taste function.

The overall aim of the present study was to investigate a new method for the screening of taste function in a clinical context. Instead of dripping liquids onto the tongue, thin edible wavers were used. One-hundred healthy subjects participated in the study (41 male, 59 female; mean age: 52 years; age range: 20-89 years). Supra-threshold taste stimuli were presented as flavoured wavers made from flour and water. Sequential testing was performed regionally on the anterior one-third of the tongue and as whole mouth testing. When comparing ratings for the 5 different wavers separately for regional and whole mouth testing, differences between qualities only emerged for regional testing. Women were found to have less difficulty in taste identification which was most pronounced for regional testing. No effects of the subjects' age were observed. In conclusion, the wavers were found to be easy to use; they have a shelf-life of 2 to 3 years and can be carried in the pocket. The results indicate that the wavers may be suited for the screening of gustatory function, especially in a clinical setting.

Responses to olfactory and intranasal trigeminal stimuli: relation to the respiratory cycle.

The aim of the study was to investigate whether the perception of intranasal chemosensory stimuli changes in relation to the respiratory cycle. We investigated 40 healthy subjects with normal olfactory function who participated in four sessions. The first session was used to adapt subjects to the experimental conditions, and, specifically, to train a certain breathing technique (velopharyngeal closure) which prevents intranasal respiratory air-flow. In each of the following three sessions one of three stimulants was tested, namely phenyl ethyl alcohol (PEA), hydrogen sulfide (H(2)S), or the trigeminal stimulant carbon dioxide (CO(2)). The sequence of testing the three stimulants was randomized across all participants. Sessions were separated by at least 1 day. Chemosensory event-related potentials (ERP) were recorded in response to 80 stimuli each. Following each stimulus subjects rated its intensity using a computerized visual analogue scale. Respiration was recorded using a probe in front of the subjects' mouth. While presentation of chemosensory stimuli was performed independent of the respiratory cycle, responses were averaged off-line according to the subjects' respiratory phase when the stimuli had been presented. Intensity of olfactory or trigeminal stimuli did not differ significantly in relation to the respiratory cycle. Olfactory ERP to phenylethyl alcohol were larger when stimuli were presented during inspiration. Similarly, responses to H(2)S tended to be larger when stimuli were presented during inspiratory phases. In addition, responses to CO(2) were larger when stimuli were presented during inspiration. Differences in relation to the respiratory cycle were found specifically for early ERP components. It is important to note that the changes of chemosensory information processing were found in the absence of changes of intranasal airflow. These data indicate on an electrophysiological level that there is priming of both olfactory and trigeminally mediated sensations in relation to the respiratory cycle.

Dacron patch infection after carotid angioplasty. A report of 6 cases.

OBJECTIVE: We describe our experience with Dacron patch infections after carotid endarterectomy (CEA). REPORT: From 633 patients undergoing carotid endarterectomy with Dacron patching, six re-presented with prosthetic infections. In 3 of the 6 cases a neck haematoma had necessitated surgical revision after the original carotid surgery. Five patients underwent interposition vein grafting and 1 vein patch angioplasty. Postoperatively, 2 patients developed a repeat infection including the 1 patient with patch angioplasty. All patients were free of infection and neurological symptoms after a maximum follow-up of 56.5 months. CONCLUSION: Following the development of haemorrhage or wound complications careful clinical surveillance should be carried out after carotid reconstruction.

Peripheral levels of inflammatory mediators in migraineurs during headache-free periods.

OBJECTIVES: The present study investigated the peripheral inflammatory changes of the trigeminovascular system by measuring the inflammatory mediators leukotriene B4 (LTB(4)), prostaglandin E2 (PGE(2)), and thromboxane B2 (TXB(2)) in the nasal fluid, as well as saliva, of patients with migraine. BACKGROUND: Migraine has been hypothesized to be as a result of changes in the peripheral or central nervous system or both. It is still unclear whether peripheral changes in the trigeminovascular system are involved in the pathogenesis of migraine. METHODS: Participants were 18 subjects, 9 patients with migraine and 9 controls, matched for age and sex. Each subject took part in one experimental session during which nasal lavage fluid and saliva samples were collected. These samples were analyzed by competitive enzyme immunoassay using goat anti-rabbit polyclonal antibody. RESULTS: With the exception of TXB(2), correlational analyses indicated good correlations between results obtained using nasal lavage or saliva (LTB(4), r(18) = 0.91; PGE(2), r(18) = 0.95). When comparing inflammatory mediators measured in controls and migraineurs, the LTB(4) level was significantly lower in migraineurs, while no differences were found for PGE(2) and TXB(2). CONCLUSIONS: The study demonstrated that nasal lavage, a noninvasive method, can be easily used for investigations of pathophysiological mechanisms of migraine. In addition, the results may indicate that there is no peripheral trigeminal sensitization in the headache-free period of migraineurs compared with controls when PGE(2), LTB(4), and TXB(2) in saliva and nasal lavage samples are measured.

Oral mucosal blood flow following dry ice stimulation in humans.

The aim of the current pilot study was to establish a procedure that would allow the investigation of microcirculatory changes in the oral cavity. The authors studied the effects of painful stimulation using dry ice (CO2). To investigate potential regional differences in the change of blood flow, recordings were made for the tongue and at the mucosa of the hard palate, lip, and oral vestibule. The authors investigated 26 patients divided into groups of younger subjects (10 men, 3 women; age range 21-31 y) and older patients (2 men, 11 women; age range 54-74 y). Mucosal blood flow (mBF) was obtained at the hard palate, at the tip of the tongue, on the midline of the oral vestibule, and at the lip. Measurements were made during rest and for 2 minutes after application of dry ice for a 10-second duration, using a pencil-shaped apparatus. Blood pressure, heart rate, cutaneous blood flow, transcutaneous partial pressure of carbon dioxiode (PCO2) and partial pressure of oxygen (PO2) were recorded. Mucosal blood flow increased at all sites in response to application of dry ice (p <0.001), with peak flow at 0.5 minute to 1.5 minutes after onset of stimulation. During the 1.5 minutes to 2 minutes, blood flow decreased at all measurement sites with a tendency to return to baseline. Heart rate, blood pressure, pCO2, PO2, and cutaneous blood flow did not show significant changes. Overall, responses in older patients showed more variance when compared with younger patients. Stimulation by dry ice appears to be an effective, noninvasive, and tolerable means to investigate mucosal blood flow at different mucosal sites. Preliminary data indicate different levels of responsiveness to painful cold stimulation at different sites on the oral and perioral mucosa; particularly, mucosal blood flow response at the tongue was least pronounced. Therefore, assessment of stimulated mucosal blood flow appears to be a promising tool to investigate the pathophysiology of a number of neurologic symptoms, eg, the burning mouth syndrome.