Short-term effect of caffeine on olfactory function in hyposmic patients.

The purpose of this study was to investigate the potential effects of caffeine in patients with olfactory loss. The suggested mechanisms of action consist in the non-selective blocking of adenosine receptors as well as inhibition of the phospodiesterase. Olfactory function was tested twice in 76 hyposmic patients either because of URTI or because of sinunasal causes. For definition of hyposmia and for later assessment of phenyl ethyl alcohol odor threshold, and odor discrimination the Sniffin Sticks data test was used. Using a double-blinded design, the participants were divided into two groups: one received a cup of espresso with caffeine (65 mg/cup), the other a cup of espresso without caffeine (placebo). Before and approximately 45 min after espresso consumption olfactory function was assessed. Across all participants, in comparison to placebo there was no significant effect of caffeine on olfactory function, regardless whether it was caused by an acute infection of the upper respiratory tract or sinunasal disease. These results indicate that-under the current conditions-the phosphodiesterase-inhibitor/adenosine-receptor agonist caffeine has little or no short-term effect on olfactory function in patients with olfactory loss.

Long-term follow-up of posttraumatic olfactory disorders.

OBJECTIVE: This study aims to determine the long-term recovery rate of posttraumatic olfactory disorders and to evaluate whether a lateralized disorder influences recovery. METHOD: Olfactory function of 67 patients with posttraumatic olfactory disorders were examined twice using the `Sniffin` Sticks` test battery. Olfactory function was classified based on composite TDI (Threshold, Discrimination and Identification) score. Subjective impairment was rated by visual analogue scale ranging from 0 to 10. RESULTS: First and second examinations were conducted an average of 16.7 months and 74 months after trauma, respectively. From first to second examination, mean TDI score of the better nostril increased significantly, the number of patients with anosmia of the better nostril decreased, and number of hyposmic and normosmic patients increased. Subjective impairment decreased. Neither age, sex, nor side differences between nostrils affected improvement. CONCLUSION: After the follow-up period, in 27% of the patients the TDI score improved ≥ 6 points score and subjective impairment decreased. A follow-up period of more than 2 years is recommended.

First experience with the fiber-enabled CO2 laser in stapes surgery and a comparison with the "one-shot" technique.

OBJECTIVE: To compare bone conduction after fiber-enabled CO2 laser perforation of the stapes footplate with conduction after the "one-shot" technique during stapedotomy in patients with otosclerosis. STUDY DESIGN: Retrospective clinical study. SETTING: Tertiary reference center. MATERIALS AND METHODS: We evaluated data from 178 patients who had undergone primary stapedotomy for suspected stapedial ankylosis. The stapes footplate was perforated using a fiber-enabled CO2 laser in 89 patients and the "one-shot" technique in the other 89. Only consecutive surgery was considered. Bone conduction thresholds were determined at 0.5, 1, 2, and 4 kHz on the first and third postoperative days in all patients; 172 patients were followed up after 1 month. Audiograms were compared with preoperative bone conduction. RESULTS: The postoperative bone conduction threshold on Day 1 was significantly worse at almost all frequencies. At 0.5 and 2 kHz, it improved within a month and was significantly different from the preoperative value. Bone conduction threshold at 4 kHz showed the greatest deterioration immediately after surgery, improving considerably in 1 month but remaining worse than at baseline. Only at 1 kHz was there no significant immediate hearing loss. Direct comparison of the fiber-enabled CO2 laser and the "one-shot" technique showed no statistically significant differences. CONCLUSION: Compared with the "one-shot" technique, the fiber-enabled CO2 laser can be used safely in stapes surgery, without great risk to the patient. In our opinion, it has practical advantages, especially in difficult anatomic conditions.

Patient adjustment to reduced olfactory function.

OBJECTIVE: To compare the importance of olfaction in daily life between patients with olfactory disorders and healthy normosmic individuals. DESIGN: Quasiexperimental. PARTICIPANTS: A total of 470 individuals (235 anosmic or hyposmic patients and 235 normosmic control individuals). MAIN OUTCOME MEASURES: The Individual Importance of Olfaction Questionnaire (IO) and olfactory testing using the "Sniffin' Sticks" test kit. RESULTS: The IO scores were lower in people with smell disorders compared with normosmic subjects (P < .001) and lower in patients with anosmia compared with hyposmic patients (P < .001). CONCLUSIONS: These scores suggest adjustment processes in the daily use of the sense of smell by patients. Patients attach less importance to their current sense of smell in daily life than do normosmic individuals. This adjustment might be an example of regaining psychological health despite acquired and long-lasting impairments.

Topographical differences in distribution and responsiveness of trigeminal sensitivity within the human nasal mucosa.

The study was designed to provide a topographical map of the sensitivity of the human nasal respiratory epithelium towards trigeminal chemosensory stimuli. As an electrophysiological measure of intranasal trigeminal activation at the level of the epithelium, we used the so-called negative mucosa potential (NMP), a measure that represents the sum of generator potentials of trigeminal receptor neurons after chemical stimulation. Sixty subjects participated (30 men and 30 women; mean age 23.5 years). Measurements were made in response to stimulation with menthol, CO(2), ethanol, and cinnamaldehyde, which are known to activate trigeminal receptors to various degrees. Recordings of the NMP were made from five intranasal sites: the anterior septum, the posterior septum, the tip of the middle turbinate, the tip of the lower turbinate, and the lateral side wall of the posterior nasal cavity. The recording electrode was positioned under endoscopic control. The largest NMP amplitudes were recorded at the anterior septum in response to stimulation with CO(2). Comparing all recording sites, significant differences were observed between responses at the posterior septum and the lateral side wall of the posterior nasal cavity in response to stimulation by ethanol, menthol, and CO(2). These findings suggest that the presence of topographical and chemosensory differences in the responsiveness of the nasal mucosa to irritants.

The course of olfactory deficits in patients with Parkinson's disease--a study based on psychophysical and electrophysiological measures.

OBJECTIVES: Patients with Parkinson's disease (PD) commonly show olfactory deficits in the early stages of the disease. These deficits can be verified psychophysically or electrophysiologically using olfactory event-related potentials (OERP). While psychophysical olfactory function in PD patients can improve over time, the course of OERPs in PD has not yet been investigated. METHODS: Olfactory function was investigated twice in 19 patients at 5-year intervals. Psychophysical tests included the "Sniffin' Sticks" test battery. In addition, OERPs were recorded in response to two odors on each side (phenyl-ethyl-alcohol: 40% (v/v), H(2)S, 6ppm). OERPs were evaluated regarding existence (yes/no). Average disease duration at follow-up was 9.0 years and the average Hoehn and Yahr score (disease stage) was 2.2. RESULTS: Psychophysically, 1 patient was normosmic, 14 were hyposmic, and 4 were functionally anosmic at the initial visit. Re-examination revealed 1 normosmic, 9 hyposmic, and 8 functionally anosmic patients. Mean olfactory function decreased significantly in all patients. OERPs were initially existent in 3 out of 19 patients. At follow-up, OERPs were no longer present in these patients, but were detectable in 3 other patients. CONCLUSIONS: Overall, mean olfactory function decreased, although improvements were observed at the individual level. We confirmed previous findings regarding psychophysical follow-up results. Electrophysiological measures showed a pattern of fluctuation in olfactory function comparable to that of the psychophysical results. These fluctuations do not seem to predict the course of the disease.