Enhanced Taste Recognition Following Subacute Treatment With The Dopamine D2/D3 Receptor Agonist Pramipexole in Healthy Volunteers.

BACKGROUND: Patients with Parkinson's disease (PD) show impaired performance in taste recognition tests, which suggests a possible dopaminergic influence on gustatory functioning. To experimentally test this hypothesis, we assessed whether pharmacological manipulation of dopaminergic signaling in healthy volunteers can affect performance in a standardized taste recognition test. METHODS: Physically and mentally healthy volunteers (n = 40, age 18-43 years) were randomly allocated to treatment with either pramipexole or placebo using a double-blind, parallel-group design. After 12 to 15 days of treatment (dose titrated up from 0.25 mg/d of pramipexole salt to 1.0 mg/d), taste recognition performance was assessed using a standardized and validated assay (taste strip test). Additionally, visual analogue scale ratings of subjective pleasantness and disgustingness of taste samples were obtained. RESULTS: Compared with the placebo group, participants receiving pramipexole showed significantly higher total recognition accuracy (medianpramipexole = 14.0, medianplacebo = 13.0, U = 264.5, P = .04). This was driven by a higher sensitivity for taste in the pramipexole group. Exploratory analysis of pleasantness and disgustingness ratings of appetitive (sweet) vs aversive (bitter) stimuli suggested that pramipexole treatment was associated with overall blunted hedonic responses, but this effect did not survive the inclusion of nausea (a side effect of treatment) as a covariate in the analysis. CONCLUSIONS: Healthy volunteers who received subacute pramipexole treatment exhibited higher taste recognition performance compared with the placebo group. This finding is consistent with a proposed role of the dopaminergic system in gustatory functioning and could have important theoretical and clinical implications.

Changes of taste perception after stapes surgery: a prospective cohort study.

PURPOSE: Taste perception is often affected after stapes surgery despite effort to preserve chorda tympani nerve. The aim was to examine changes of particular taste qualities and their recovery after operation of otosclerosis. MATERIALS AND METHODS: Taste function was prospectively investigated with a questionnaire and a taste strip test (TST) preoperatively, 3-5 days and 1 year after stapes surgery with the preservation of CTN. RESULTS: In the early postoperative examination, 34/42 patients had a lower TST score, 7/42 decrease of taste in the questionnaire. One year after surgery, 11/42 patients had a lower TST score, 1/42 patients decrease of taste in the questionnaire. The most pronounced decrease in the TST score was in sweet (- 1.76 points, p < 0.001), followed by bitter (- 1.71 points, p < 0.001), salty (- 1.64 points, p < 0.001) and sour taste (- 1.33 points, p < 0.001). The sour taste had a significant lower alteration compared to others. Men had significantly pronounced alteration in salty taste compared to women. The complete recovery was proved in bitter taste. Better recovery in bitter taste was observed in patients younger than 45 years of age. CONCLUSIONS: Gustatory changes after stapes surgery are mostly transient with different impairment and recovery rate for particular taste qualities. A sour taste seems to be relatively resistant to damage. The best recovery rate is in a bitter taste, especially in younger patients.

Relationship between subjective taste sensations and taste strip test in patients with taste disorders with and without burning mouth syndrome.

Background/purpose: Both subjective and objective evaluations are required to assess taste function. Evaluation of taste function has important clinical significances in patients with burning mouth syndrome (BMS) due to pain-taste interactions. The purpose of this study was to investigate the relationship between subjective and objective taste evaluations in patients with taste disorders based on the presence of BMS. Materials and methods: Fifty-one patients with taste disturbances were included. The patients completed questionnaires on subjective taste sensations. The taste strip test was performed to examine objective taste function. The patients were divided into two groups: subjects with BMS (n = 24, 3 males and 21 females) and without BMS (n = 27, 8 males and 19 females). Results: Significant differences were not observed in age, age distribution, and gender distribution between the groups. There were no significant differences in self-reported taste abilities based on the presence of BMS. However, the taste strip test showed higher correct answer rates for bitterness (P = 0.027) in the patients with BMS. In addition, a significant difference (P = 0.034) was observed in the distribution of objective types of taste disorders between the groups. A significant correlation between the subjective and objective evaluation results was observed only in patients with BMS. Conclusion: In patients with taste disorders, patients with BMS had significant correlations between subjective and objective evaluations and different distributions in the types of taste disorders compared with those without BMS. The presence or absence of BMS should be evaluated in the diagnosis and management of taste disorders.

Olfactory and Gustatory Function After Bariatric Surgery.

BACKGROUND: Neither hormone levels nor malabsorption alone fully explains the distinct weight loss after bariatric surgery in morbidly obese patients. Postoperatively, patients regularly report a change in the sense of taste and the development of food aversions. Hedonic and sensory components like olfactory and gustatory stimuli significantly affect appetite and flavour. METHODS: We prospectively analysed the orthonasal olfactory and gustatory function with psychophysical testing in 44 patients undergoing laparoscopic Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG) or adjustable gastric banding (AGB) and in 23 healthy controls. RESULTS: About 22.7 % of morbidly obese patients were hyposmic, showing significantly lower threshold-discrimination-identification (TDI) scores (p = 0.009) with decreased discrimination and identification ability. In addition, 22.7 % of patients were tested to be limited in gustatory function, with significantly lower taste strip test (TST) scores (p = 0.003). Six months after surgery, olfactory and gustatory function was not different when compared to healthy controls. CONCLUSIONS: Due to obesity, patients frequently show impaired olfactory and gustatory function. Six months after laparoscopic bariatric surgery, both chemosensory functions improve. The TDI test is an appropriate tool to measure olfactory function in obese patients.