Biomedical subjects

Thomas Hummel

Publications and source records attributed to Thomas Hummel.

At least 109 records · Page 6Linked to original sources

PubMed2002

Clinical assessment of retronasal olfactory function.

OBJECTIVES: To develop a test kit for the simple assessment of retronasal olfactory function and to compare orthonasal and retronasal olfactory function in healthy subjects and patients with olfactory disorders. DESIGN AND PATIENTS: We tested 230 individuals with normosmia, hyposmia, and anosmia using grocery-available powders. Initially, 30 different substances were investigated. Subjects identified each substance using a list with 4 verbal items (forced choice). After preliminary experiments, 20 items were selected according to the degree to which they were identified by normosmic and anosmic subjects. Orthonasal olfactory function was assessed psychophysically using "sniffin' sticks," which includes tests for odor identification, discrimination, and butanol odor thresholds. In addition, anosmia was confirmed electrophysiologically by means of olfactory-evoked potentials. RESULTS: In healthy subjects, there was a test-retest reliability correlation of r(27) = 0.76 for retronasal olfactory function, which is similar to other odor identification tests. Retronasal testing in normosmic subjects allowed for the discrimination of sex-related differences, with women scoring higher than men (P =.007), and the identification of a slight decrease with age (r(120) = -0.20; P =.03). Orthonasal and retronasal identification of odors was found to correlate (r(86) = 0.78; P<.001). Retronasal testing allowed for the discrimination between normosmia, hyposmia, and anosmia (P<.001). In addition, retronasal performance of anosmic patients appeared to improve with duration of anosmia (P =.03). No difference was found between patients with anosmia of different origin. CONCLUSION: Results of the present investigation indicate that the assessment of retronasal olfactory function is possible using oral stimulus presentation.

Adolescent↗

PubMed2002

Characteristics of olfactory disorders in relation to major causes of olfactory loss.

OBJECTIVE: To investigate the consequences of olfactory loss and explore specific questions related to the effect of duration of olfactory loss, degree of olfactory sensitivity, and cause of the olfactory loss. PATIENTS: A total of 278 consecutive patients with hyposmia or anosmia were examined. RESULTS: Causes of olfactory loss were categorized as follows: trauma (17%), upper respiratory tract infection (URI) (39%), sinonasal disease (21%), congenital anosmia (3%), idiopathic causes (18%), or other causes (3%). Our data suggest that (1) recovery rate was higher in URI olfactory loss than in olfactory loss from other causes; (2) likelihood of recovery seemed to decrease with increased duration of olfactory loss; and (3) the elderly are more prone to URI olfactory loss than younger patients. Regarding changes in quality of life (QoL), we found that (1) in most patients olfactory loss caused food-related problems; (2) loss in QoL did not change with duration of olfactory loss; (3) younger patients had more complaints than older ones, and women had more complaints than men; (4) complaint scores were higher in hyposmic patients than in anosmic patients; and (5) self-rated depression did not relate to measured olfactory function. CONCLUSIONS: Among many complaints of olfactory loss, the predominant ones were food related. This loss in QoL seemed to be of greater importance in younger than in older people, and women seem to be affected more strongly than men.

Activities of Daily Living↗

PubMed2002

Assessment of pharyngeal sensitivity to mechanical stimuli using psychophysical and electrophysiological techniques.

The investigation was aimed to assess pharyngeal sensitivity by means of intensity ratings and event-related potentials (ERPs) to mechanical stimulation. Twenty healthy subjects participated (14 female, mean age 23.6 years). Both intensity ratings and ERP were obtained in response to three intensities of mechanical stimuli (air puffs) applied to the nasal cavity or the pharynx. Test-retest reliability was investigated for two sessions performed on different days. The study provided the following: (1) intensity ratings of nasal or pharyngeal stimuli increased with increasing stimulus intensity (P < 0.001); (2) they also exhibited a significant test-retest reliability (r </= 0.78) which was best for higher stimulus intensities; (3) ERP amplitudes increased and latencies shortened with increasing stimulus intensity (factor 'intensity': P < 0.013); (4) test-retest reliability was best at centro-frontal recording sites where significant correlations were found for both ERP amplitudes and latencies; (5) ERP to pharyngeal stimulation correlated significantly with perceived stimulus intensity (e.g., latency N1 at Cz: r = -0.73, P = 0.001). In conclusion, mechanical stimulation of the pharynx can be applied to reliably elicit ERPs which are related to both stimulus intensity and intensity ratings. This model may be useful in the investigation of cough-related changes in pharyngeal sensitivity.

Adult↗

PubMed2002

Anti-inflammatory and surgical therapy of olfactory disorders related to sino-nasal disease.

Olfactory loss may be caused by mechanical obstruction or inflammation of the olfactory epithelium due to allergic/non-allergic rhinitis and chronic sinusitis with or without polyps. Treatment of olfactory loss related to sino-nasal disease is possible. Apart from surgical approaches and/or treatment with antibiotics, both systemic and topical steroids are effectively used in the therapy of olfactory loss related to sino-nasal disease. In most cases improvement of olfactory function appears to relate to the anti-inflammatory actions of the steroids used. While some details of therapeutic effect and dose regimen are not clear, systemic steroids are often helpful even in patients without nasal obstruction due to polyps or obvious inflammatory changes.

Anti-Bacterial Agents↗

PubMed2002

Intranasal volume and olfactory function.

The aim of this exploratory study was to identify the volume intranasal segments as they relate to parameters of olfactory function. Fifty healthy male volunteers (age range 22-59 years, mean age 28.5 years) were included. Olfactory function was measured by lateralized phenyl ethyl alcohol odor thresholds and odor discrimination, and by bilateral odor identification. Magnetic resonance imaging of the nasal cavity was performed immediately following olfactometry. To correlate the results of olfactometry with intranasal volume, each nasal cavity was divided into 11 segments. Significant correlations were found between the odor thresholds and volumes of the anterior part of the lower and upper meatus of the right nasal cavity. These results reveal that two nasal segments are important for inter-individual differences of odor thresholds in healthy subjects: (i) the segment in the upper meatus below the cribriform plate and (ii) the anterior segment of the inferior meatus. The latter finding is of special interest for nasal surgery, which allows modification of this volume through resection of the inferior turbinate and/or septoplasty.

Adult↗

PubMed2002

Lipoic acid in the treatment of smell dysfunction following viral infection of the upper respiratory tract.

OBJECTIVES/HYPOTHESIS: The study aimed to investigate the potential therapeutic effects of alpha-lipoic acid in olfactory loss following infections of the upper respiratory tract. Possible mechanisms of actions include the release of nerve growth factor and antioxidative effects, both of which may be helpful in the regeneration of olfactory receptor neurons. STUDY DESIGN: Unblinded, prospective clinical trial. METHODS: A total of 23 patients participated (13 women, 10 men; mean age 57 y, age range 22-79 y; mean duration of olfactory loss, 14 mo; range, 4 to 33 mo); 19 of them were hyposmic and 4 had functional anosmia. Alpha-lipoic acid was used orally at a dose of 600 mg/day; it was prescribed for an average period of 4.5 months. Olfactory function was assessed using olfactory tests for phenyl ethyl alcohol odor threshold, odor discrimination, and odor identification. RESULTS: Seven patients (30%) showed no change in olfactory function. Two patients (9%) exhibited a moderate decrease in olfactory function; in contrast, six patients (26%) showed moderate and eight patients (35%) remarkable increase in olfactory function. Two of the 4 patients with functional anosmia reached hyposmia; 5 of 19 hyposmic patients became normosmic. Overall, this resulted in a significant improvement in olfactory function following treatment (P =.002). At the end of treatment parosmias were less frequent (22%) than at the beginning of therapy (48%). Interestingly, recovery of olfactory function appeared to be more pronounced in younger patients than in patients above the age of 60 years (P =.018). CONCLUSIONS: The results indicate that alpha-lipoic acid may be helpful in patients with olfactory loss after upper respiratory tract infection. However, to judge the true potential of this treatment, the outcome of double-blind, placebo-controlled studies in large groups of patients must be awaited, especially when considering the relatively high rate of spontaneous recovery in olfactory loss after upper respiratory tract infection.

Adult↗

PubMed2002

MR evaluation in patients with isolated anosmia since birth or early childhood.

BACKGROUND AND PURPOSE: Anosmias with chromosomal disorders has been well investigated. However, isolated anosmia (IA) has received less attention, although it occurs more frequently. We compared frontobasal structures in patients with IA since birth or early childhood with those in control subjects. METHODS: Imaging findings obtained in 16 patients with IA were compared with those obtained in eight control subjects. Imaging was performed with a standard quadrature head coil at 1.5 T. T1-weighted spin-echo (coronal plane perpendicular to frontal skull base; section thickness, 3 mm; pixels, 0.43 x 0.39 mm) and sagittal T1-weighted magnetization-prepared rapid gradient-echo (voxels, 1.0 x 1.0 x 1.0 mm) sequences were performed. We assessed the length and depth of the olfactory sulcus, olfactory bulb volume, and olfactory sulcus depth in the plane of the posterior tangent through the eyeballs (PPTE). RESULTS: Five patients with IA had bilateral hypoplastic olfactory bulbs. Three patients with IA had hypoplastic olfactory bulbs on the right and aplastic olfactory bulbs on the left. Eight patients with IA had bilaterally aplastic olfactory bulbs. The depth of the olfactory sulcus at the level of the PPTE was smaller in patients with IA than in control subjects. The depth of the olfactory sulcus was greater on the right than on the left, and there was no overlap. Among patients with IA, the depth of the olfactory sulcus differed significantly between those with and those without visible olfactory tracts. CONCLUSION: The depth of the olfactory sulcus at the level of the PPTE reflects the presence of olfactory tracts. The presence or absence of the olfactory tract may therefore have some association with cortical growth of the olfactory sulcus region. The olfactory sulcus is deeper on the right than on the left, particularly in patients with IA. We speculate that olfaction may be processed predominantly in the right hemisphere.

Adolescent↗

PubMed2002

The quinoxaline derivative caroverine in the treatment of sensorineural smell disorders: a proof-of-concept study.

The treatment of non-conductive olfactory disorders is to a large extent an unsolved problem. This proof-of-concept study focused on possible effects of the N-methyl-D-aspartate (NMDA) antagonist caroverine. Potential mechanisms for the hypothesized effect included reduced feedback inhibition in the olfactory bulb as a consequence of NMDA antagonistic actions and antagonism of an excitotoxic action of glutamate. A total of 77 consecutive patients with non-conductive olfactory disorders were included in the study. Fifty-one patients received caroverine for 4 weeks (120 mg/day); 26 controls matched for age, gender and duration of olfactory loss were treated with zinc sulfate for the same length of time (400 mg/day). Olfactory sensitivity was evaluated before and after treatment. Testing included assessment of n-butanol odor threshold and odor identification. When compared to baseline, treatment with caroverine improved both odor thresholds (p = 0.005) and odor identification (p = 0.042) in anosmic patients. In hyposmic patients it significantly improved odor identification ability (p = 0.041). In contrast, zinc sulfate had no significant effect on olfactory function. These results indicate that caroverine appears to be effective for the treatment of non-conductive smell disorders.

Adolescent↗

PubMed1997

Bilateral hyperalgesia to chemical stimulation of the nasal mucosa following unilateral inflammation.

The aim of the present study was to investigate the bilateral sensory changes to chemical noxious stimuli in the trigeminally innervated areas following unilateral nasal inflammation. Twenty healthy volunteers took part in five experiments. Intranasal inflammation was induced by means of a constant flow of cold air (145 ml/s); temperature and humidity of the airstream were varied across experiments. For the non-inflamed (NOI) condition, air temperature was 36 degrees C and its humidity 80%. In the other experiments the airstream's humidity was either 25% or 80% with a constant temperature of 20 degrees C; the airstream was applied to the left or right nostril. In order to produce noxious chemical stimuli, gaseous CO2 was applied to the left nostril (36 stimuli of 200 ms; 65% v/v CO2; interstimulus interval 30 s). Subjects rated the pain intensity of the stimuli by means of a visual analogue scale (VAS). As an indicator for hyperalgesia, the subjective pain ratings to CO2 stimuli increased not only while they were applied at the inflamed site, but also during their application contralaterally to the inflamed side. These results demonstrate the occurrence of bilateral hyperalgesia to noxious chemical stimuli in the nasal mucosa following unilateral inflammation which indicates the involvement of central changes.

Adult↗

PubMed1993

[Computer-assisted teaching in pharmacology]

Computer-assisted teaching has become a valuable alternative to experimental animals in the training of medical students. The available software may be classified as follows: 1.Computerised textbooks, which include text, graphics, animations, videoclips and sound. 2.Programmes prompting the student to make decisions which may be commented by the programme. 3.Interactive simulations of biological processes. 4.Computer-based, interactive engineering of experiments which include the processing of off-line recorded data. Within the last ten years, programmes fitting all of these categories have been developed at the Department of Experimental and Clinical Pharmacology and Toxicology at the University of Erlangen-Nürnberg. Although both, development and maintenance are time-consuming processes, these programs have been introduced most successfully to medical students in pharmacology which, in turn, emphasises the growing importance of computer-based teaching.

Journal Article↗

PubMedDate not supplied

Areas of capsaicin-induced secondary hyperalgesia and allodynia are reduced by a single chiropractic adjustment: a preliminary study.

INTRODUCTION: The aim of the study was to investigate the hypoalgesic effects of a single spinal manipulation treatment on acute inflammatory reactions and pain induced by cutaneous application of capsaicin. METHODS: Twenty healthy subjects participated in the experiment, which consisted of 2 sessions. In both sessions, following control measurements, topical capsaicin was applied to the right or left forearm to induce cutaneous inflammatory reactions. The cream was removed after 20 minutes. Then subjects received either spinal manipulation treatment (SMT) or "nonspinal manipulation treatment" (N-SMT), respectively. In control as well as pretreatment and posttreatment intervals, the following tests were performed: measurement of the areas of mechanical hyperalgesia and stroking allodynia, assessment of spontaneous pain, and measurement of blood flow. RESULTS: The results confirmed that topical capsaicin induced inflammatory reactions based on occurrence of hyperalgesia and allodynia, augmented pain perception, and increased blood flow following capsaicin application compared with the control session. When compared with N-SMT, spontaneous pain was rated significantly lower post-SMT (P <.014). In addition, areas of both secondary hyperalgesia and allodynia decreased after SMT (hyperalgesia: P <.007; allodynia: P <.003). However, there was no significant treatment effect for local blood flow. CONCLUSION: These results suggest hypoalgesic effects following a single SMT. As local vascular parameter was not affected by the single SMT, the hypoalgesic effects appear to be due to central mechanisms.

Administration, Cutaneous↗

PubMedDate not supplied

Chemosensory function in patients with vagal nerve stimulators.

Chemosensory function is determined by the interplay of numerous sensory modalities. The present study aimed to evaluate the possible influence of electrical stimulation of the left-sided vagal nerve on gustatory and olfactory function in patients with vagal nerve stimulation (VNS). Gustation and olfaction were tested using psychophysical techniques; olfactory function was additionally evaluated using event-related potentials. A total of 11 subjects participated (six men and five women, aged 21 to 56 years). The vagal stimulator was run in "rapid cycle mode" in 10 patients, whereas one patient was treated with "normal mode" VNS. Subjects participated in two sessions, with the vagal stimulator switched on and off, respectively. The sequence of the two sessions was randomized across all participants. Using air-dilution, olfactometry event-related potentials to the specific olfactory stimulant H2S were recorded. Psychophysical tests were performed using the "Sniffin' Sticks" test kit, a test for retronasal olfactory function, and a gustatory test based on impregnated filter paper. The study yielded the following major results: (1) VNS produced a prolongation of P2 latencies of olfactory ERP, and (2) patients with therapeutic benefit from VNS in terms of seizure control had larger amplitudes during the on period than during the off period. In conclusion, using electrophysiological measures of olfactory function, the present study indicated a significant role of VNS in the processing of olfactory information.

Adult↗

PubMedDate not supplied

Severe chemotherapy-induced parosmia.

BACKGROUND: Smell and taste disorders are among the side effects of chemo- and radiotherapy. Although direct radionecrosis of the salivary glands and the taste buds might explain the chemosensory problems after radiotherapy, the olfactory and gustatory complaints seen after chemotherapy remain unexplained. The patients reporting olfactory symptoms rarely complain about qualitative olfactory disorders such as parosmia or phantosmia. Quantitative olfactory loss such as anosmia and hyposmia seem to be more frequent. METHODS: We present the case of a 63-year-old woman with chemotherapy-induced parosmia leading to severe nutrition and appetite problems resulting in a life-threatening weight loss. RESULTS: With the aid of a simple nose clip the parosmia could be abolished and oral food intake became possible again. Parosmia resolved gradually over an observation period of 9 months, in parallel to an increase of olfactory sensitivity. The patient progressively gained appetite and weight. CONCLUSION: Parosmia can occur as a severe and potentially life-threatening complication of chemotherapy. This rare presentation of parosmia illustrates the importance of olfactory testing with an adequate recognition of the underlying problem and a consecutive treatment.

Antineoplastic Combined Chemotherapy Protocols↗

PubMedDate not supplied

Studies on the effects of ice collars on nasal blood volume using optical rhinometry.

BACKGROUND: The possible benefit of ice collars for treatment of nosebleed is controversial. The aim of this study was to investigate changes of nasal blood volume before and after application of ice collars to the neck. Nasal blood volume was investigated using optical rhinometry. METHODS: A total of 15 young, healthy volunteers participated. After ice collars were placed on the neck area of the subjects, changes in the blood volume of the nose were measured by means of optical rhinometry for the whole nose, but also regionally at the nasal septum (Kiesselbach's area). After baseline measurements over 1 minute, the ice collar was applied. Optical rhinometric measurements were performed continuously. RESULTS: Although the ice collar showed no effect on the blood volume of the whole nose, there was a significant decrease in blood volume (p < 0.01) at the septum. CONCLUSION: Application of ice collars to the neck area of the subjects is followed by a decrease in blood volume of Kiesselbach's area, which may provide the basis for the clinical observation that ice collars are helpful in the treatment of nosebleeds.

Adult↗

PubMedDate not supplied

Olfactory function in chronic renal failure.

BACKGROUND: Patients with chronic renal failure (CRF) show a high prevalence of poor nutritional state so that dietary treatment becomes a significant part of the therapeutic regimen. Because smell plays an important role in nutrition, this study aimed to investigate olfactory function in CRF patients. METHODS: A total of 64 CRF patients were investigated. Forty-nine of them were treated with hemodialysis, 15 CRF patients were not dialysis dependent. For comparison we examined 15 healthy subjects. Olfactory function was assessed for odor discrimination, odor identification, and butanol odor thresholds. RESULTS: Olfactory loss was found in 56% of the patients, with 3 functional anosmics and 33 hyposmics. CRF had specific effects on individual tests of olfactory function. Elevated odor thresholds werefound in 11% of patients, 38% of patients had reduced odor discrimination, and 48% of patients exhibited deficits in odor identification. Results of psychological tests (Mini-Mental State Examination and Trail-Making Test) correlated with results from odor identification (p < 0.01) and discrimination (p < 0.01) but not with odor thresholds. CONCLUSIONS: The ability to discriminate and identify odors was found severely impaired whereas odor thresholds were similar to what is seen in the general population. Consequently, CRF patients should be counseled with regard to the possibility of reduced chemosensory functions.

Adult↗

PubMedDate not supplied

Local and systemic administration of corticosteroids in the treatment of olfactory loss.

BACKGROUND: The aim of this study was to evaluate the benefit of patients with olfactory dysfunction from local (group A) or systemic (group B) administration of corticosteroids. METHODS: This unblinded study was conducted at a smell and taste outpatient clinic of an institutional referral center. Patients with olfactory loss after infections of the upper respiratory tract, patients with apparent sinonasal disease, and patients suffering from "idiopathic" smell loss were included. Effects of mometasone nasal spray, administered for 1-3 months, were studied in 37 patients. In addition, effects of oral prednisolone were analyzed in 55 patients who received decreasing doses over 21 days, starting with a dose of 40 mg. Olfactory function before and after treatment was measured. RESULTS: Although odor identification scores tended to increase (p = 0.05), mometasone nasal spray did not significantly improve olfactory function, when looking at the entire group of patients or when analyzing the three diagnostic categories separately. In contrast, after systemic administration of corticosteroids, improvement of olfactory function was seen over all diagnostic categories (p < 0.001). Interestingly, olfactory function also improved in patients diagnosed with olfactory loss after upper respiratory tract infection (p = 0.05) and in patients initially diagnosed with "idiopathic," olfactory dysfunction (p = 0.008). CONCLUSION: In many patients, local application of corticosteroids appears to have little or no positive effect on olfactory dysfunction, especially when considering long-term changes. Duration of disease, the patient's age/sex, or the presence of parosmia does not appear to predict the response to therapy with corticosteroids.

Administration, Intranasal↗

PubMedDate not supplied

What is the correlation between ratings and measures of olfactory function in patients with olfactory loss?

BACKGROUND: Major complaints of many patients with olfactory dysfunction relate to the impairment of quality of life. Nevertheless, it is unclear to what extent there is a correlation between ratings of olfactory abilities/impairment and olfactory function. METHODS: Patients with olfactory dysfunction (n = 152) were examined psychometrically using the "Sniffin' Sticks" test battery. Ratings of olfactory function and ratings of impairment were recorded using visual analog scales. RESULTS: Following standardized olfactory testing, 78 of the 152 patients were categorized as functionally anosmic, 64 as hyposmic, and 10 as normosmic. Groups differed significantly with regard to ratings of olfactory function. Functionally anosmic patients rated impairment to be significantly higher compared with hyposmic and normosmic patients. Ratings of olfactory function correlated significantly with measured olfactory function (r = +0.57) and ratings of impairment (r = -0.30). CONCLUSION: There was a moderate correlation between ratings and measures of olfactory function. On average, functionally anosmic patients recognized their olfactory loss, although, on an individual basis, there were striking differences between measures and ratings of olfactory function.

Adolescent↗

PubMedDate not supplied

Computed tomography scans in the evaluation of patients with olfactory dysfunction.

BACKGROUND: The necessity of computed tomography (CT) scans of the olfactory cleft and the sinuses in patients presenting with olfactory dysfunction is a matter of debate. This study aimed to investigate the significance of CT scans for the diagnosis of olfactory loss and for therapeutic decisions. METHODS: This retrospective study included 137 consecutive patients presenting with the main complaint of olfactory loss. Standardized history; ear, nose, and throat examination; and olfactory tests were administered. In addition, a CT scan of the nasal sinuses was obtained. The assumed diagnosis (sinonasal disease [SND] or non-SND) was compared with the diagnosis when additionally considering results from the CT scan. RESULTS: CT scans suggested SND in 7/101 patients, without clinical evidence of its presence. In 12/36 patients with suspected SND-related olfactory loss, no signs of SND were detected in CT scans. CONCLUSION: CT scans are useful to diagnose conductive/inflammatory olfactory loss in patients suspected of non-SND, which may then justify a course with systemic steroids. Alternatively, considering low costs and rare side effects of a short course with steroids in selected patients, CT scans appear to be of clinical significance only when surgical treatment is contemplated or where the use of systemic corticosteroids is not possible.

Adult↗