Taste Disorder and Tongue Numbness After Lithium Overdose

PURPOSE

Drug-induced taste disturbances are prevalent in clinical practice, with dysgeusia being a frequent manifestation. This study aims to present a case of taste disorders and tongue numbness induced by a lithium overdose.

CASE REPORT

A 33-year-old woman with bipolar II disorder attempted suicide by ingesting multiple drugs, including lithium and benzodiazepines. She exhibited weakness but was conscious after admission. Laboratory analyses indicated elevated serum lithium and urine benzodiazepine levels. Admitted to a psychiatric ward, her symptoms included diarrhea, poor appetite, and postprandial nausea. Two weeks later, she reported altered taste sensations and tongue numbness following the overdose. Her ongoing medication included venlafaxine, valproate sodium, and clozapine. Symptoms improved over time without specific treatment, aligning with increased appetite and weight gain.

CONCLUSION

Drug-induced taste disturbances have a substantial impact on patients' quality of life and medication adherence. This case brings attention to taste disorders induced by lithium and suggests potential mechanisms that could contribute to taste alterations. It underscores the importance of conducting thorough assessments in patients experiencing gustatory symptoms, particularly during the ongoing pandemic.

Association of gustatory dysfunction and Alzheimer

BACKGROUND

Chemosensory dysfunction has been reported to be involved in the pathogenesis of Alzheimer’s disease (AD). Compared with olfaction, gustatory dysfunction in AD has not been evaluated in depth. We reviewed previously published studies regarding gustatory dysfunction in patients with AD compared with healthy controls.

METHODS

A systematic review was conducted by searching the MEDLINE, Cochrane Library, Embase, and PubMed databases covering publications from January 2000 to February 2023. The search was performed using the keyword "Alzheimer* AND (gustatory OR taste OR gustation)." Only studies that performed gustatory function testing and compared the results between patients with AD and healthy controls were included. A random-effects meta-analysis was performed.

RESULTS

Twelve articles were finally included, and various gustatory tests including taste strips, the taste disk test, taste solutions, and subjective questionnaires were applied. Overall gustatory function based on the taste strip test was significantly decreased in patients with AD compared with controls in two out of three papers. The overall gustatory function of patients with AD was significantly decreased in all studies based on the taste disk and taste solution tests. We also found that the sweet taste test showed low heterogeneity across all the included studies, and there was low publication bias. In studies using subjective questionnaires, gustatory function was not significantly different between patients with AD and healthy controls in the meta-analysis.

CONCLUSIONS

Based on these studies, gustatory dysfunction diagnosed by gustatory function testing was closely related to AD. However, the results of subjective questionnaires were not significantly different between patients with AD and healthy controls in the current meta-analysis. As the number of studies and enrolled subjects was limited and unified gustatory function testing was lacking, further studies are needed to confirm this relationship.

Burning mouth syndrome: Analysis of diagnostic delay in 500 patients

OBJECTIVES

To assess the diagnostic delay, the number and type of referrals and the clinical and psychological profile in a wide sample of patients with Burning Mouth Syndrome (BMS).

MATERIALS AND METHODS

Data on the disease onset, oral symptoms, type and number of practitioners consulted, misdiagnoses, and the presence of medically unexplained extraoral physical symptoms were recorded in 500 BMS patients. Potential predictors of diagnostic delay were also evaluated.

RESULTS

The mean diagnostic delay was 29.71 ± 47.19 months. An average of 2.61 ± 1.65 practitioners were consulted by each patient, the most frequent being the general physicians (287; 57.4%), maxillofacial surgeons (111; 22.2%), and otolaryngologists (104; 20.8%). The mean number of misdiagnoses was 3.54 ± 1.85. Nonspecific stomatitis, candidiasis, and gastroesophageal reflux were the most common misdiagnoses. Higher age, low education, the presence of dysgeusia, and a previous history of psychiatric illness were predictors of a longer diagnostic delay (p-value: 0.028, 0.050, 0.007, 0.034, respectively).

CONCLUSIONS

The lack of knowledge among specialists, the high rate of misdiagnosis, and the diagnostic delay of BMS highlight the need to introduce educational interventions in all medical specialties in order to promote an early and appropriate diagnosis, thereby improving the prognosis and quality of life of the patients.

Time-frequency analysis of gustatory event related potentials (gERP) in taste disorders

In taste disorders, the key to a correct diagnosis and an adequate treatment is an objective assessment. Compared to psychophysical tests, EEG-derived gustatory event-related potentials (gERP) could be used as a less biased measure. However, the responses identified using conventional time-domain averaging show a low signal-to-noise ratio. This study included 44 patients with dysgeusia and 59 healthy participants, who underwent a comprehensive clinical examination of gustatory function. gERPs were recorded in response to stimulation with two concentrations of salty solutions, which were applied with a high precision gustometer. Group differences were examined using gERP analyzed in the canonical time domain and with Time-Frequency Analyses (TFA). Dysgeusic patients showed significantly lower scores for gustatory chemical and electrical stimuli. gERPs failed to show significant differences in amplitudes or latencies between groups. However, TFA showed that gustatory activations were characterized by a stronger power in controls than in patients in the low frequencies (0.1-4 Hz), and a higher desynchronization in the alpha-band (8-12 Hz). Hence, gERPs reflect the altered taste sensation in patients with dysgeusia. TFA appears to enhance the signal-to-noise ratio commonly present when using conventional time-domain averaging, and might be of assistance for the diagnosis of dysgeusia.

The relationship between loneliness, psychological resilience, quality of life and taste change in cancer patients receiving chemotherapy

PURPOSE

This study aimed to determine the correlation between taste change, nutritional intake and quality of life in cancer patients receiving chemotherapy. A total of 610 (F = 314, M = 296) volunteers aged 19 and 65 who received outpatient chemotherapy treatment participated in the study.

METHODS

Individuals' general information was obtained, anthropometric measurements were carried out, malnutrition status (Patient-Generated Subjective Global Assessment PG-SGA), loneliness (Cancer Loneliness Scale), psychological resilience (Psychological Resilience Scale), quality of life (Quality of Life Scale (EORT QLQ-C30) and taste changes were scrutinized [Chemotherapy-Induced Taste Alteration Scale (CiTAS)].

RESULTS

There was a negative correlation between the Cancer Loneliness Scale and PG-SGA and General Health Status (r = -0.494, p = 0.000; r = -0.406, p = 0.000) and a positive correlation with Symptom Scales (r = 0.484, p = 0.000; r = 0.506, p = 0.000) (p < 0.05). There was a positive correlation between the Psychological Resilience Scale and General Health Status (r = 0.393, P = 0.000), Functional Scales (r = 0.349, P = 0.000), and a negative correlation between Symptom Scales (r = -0.302, p = 0.000) (p < 0.05). 70.9% of men and 70.7% of women had severe malnutrition. General Taste Changes, General Health and Symptom Scale values were significant predictors of severe malnutrition status (p < 0.05).

CONCLUSION

The symptoms that develop during the treatment process cause many psychological problems. Before starting treatment, patients should be evaluated comprehensively, depression anxiety levels and quality of life levels should be determined, and precautions should be taken accordingly.

Oral manifestations of COVID-19 in unvaccinated patients: a cross-sectional study

BACKGROUND

Early studies have highlighted the possible development of dysgeusia and anosmia in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and these manifestations should be considered a potential indication of coronavirus disease 19 (COVID-19). As potential contributors to these symptoms, dentists should perform careful oral and oropharyngeal examinations and document suspicious oral lesions in patients with COVID-19, especially in those who complain of loss of taste and smell. The study's objective was to assess the prevalence of oral manifestations among ambulatory unvaccinated symptomatic patients with suspected COVID-19 during the acute phase of the disease.

METHODS

This cross-sectional study evaluated oral manifestations in adults (aged ≥ 18 years) with suspected and confirmed SARS-CoV-2 infection. Chi-square and Fisher's exact tests were used to compare data between the groups (rRT-PCR-positive and rRT-PCR-negative patients).

RESULTS

One hundred thirty-six participants were included. Most were female (n = 79; 58.1%), with a mean age of 39.53 (± 14.17) years. Of these, 54 (39.7%) had a positive rRT-PCR test, and 82 (60.3%) had negative rRT-PCR results. Oral manifestations were observed in 40 participants (74.1%) in the rRT-PCR-positive group and 67 participants (81.7%) in the rRT-PCR-negative group. The most common oral manifestations were xerostomia (n = 85; 62.5%) and dysgeusia/ageusia (n = 57; 41.9%). Different rates of gingivitis (n = 12; 22.2% vs. n = 5; 6.1%; p = 0.005) and halitosis (n = 7; 13.0% vs. n = 1; 1.2%; p = 0.007) were observed between the rRT-PCR-positive and -negative groups, respectively. Mouth ulcers, glossitis, tongue coating, and petechiae were reported in both groups without significant differences.

CONCLUSIONS

A high prevalence of oral manifestations was observed in symptomatic patients with suspected or confirmed COVID-19.

CLINICAL RELEVANCE

This study highlights the importance of routine oral examinations by dentists as part of the multidisciplinary care of COVID-19 patients.

[A case of left dysgeusia due to hemorrhage near the left superior cerebellar peduncle]

We report a rare case with unilateral dysgeusia due to cerebrovascular disease. A 45-year-old man was admitted to the hospital with a sudden onset of dysesthesia in the right face and upper and lower limbs. A CT scan revealed a left pontine hemorrhage. A day after onset, the patient became aware of unilateral dysgeusia. Electrogustometry showed significantly higher thresholds in the left chorda tympani nerve and glossopharyngeal nerve compared to the right nerves. We diagnosed the hemorrhage caused unilateral dysgeusia. Although dysesthesia in the right face and upper and lower limbs disappeared, the dysgeusia in the left tongue persisted six months after symptom onset. Based on the neurological and radiological findings in this case, we discuss the central gustatory pathway with literatures.

[Gustatory disorders in COVID-19]

Taste disturbances are present in 20.3-88.0% of COVID-19 cases and are the first signs of infection in 11.0-18.1% of cases. They often manifested 3-7 days after the onset of general respiratory symptoms and last 2 to 16 days, followed by recovery. There are also prolonged disturbances of taste sensation (up to 61-76 days or more), which is associated with damage to various types of receptor cells of the mucous membrane of the tongue. More severe taste disturbances are recorded in the elderly. In women, changes in taste sensation are noted more often than in men, and with a longer recovery period. Severe and critical forms of taste disorders predominate in COVID-19; dysgeusia, as a rule, prevails over hypogeusia and ageusia. Taste disturbance is a common clinical symptom in COVID-19, which can and should be considered as a marker of early manifestation of coronavirus infection.

Dysgeusia: A review in the context of COVID-19

Background

Taste disorders in general, and dysgeusia in particular, are relatively common disorders that may be a sign of a more complex acute or chronic medical condition. During the COVID-19 pandemic, taste disorders have found their way into the realm of general as well as specialty dentistry, with significance in screening for patients who potentially may have the virus.

Types of Studies Reviewed

The authors searched electronic databases (PubMed, Embase, Web of Science, Google Scholar) for studies focused on dysgeusia, ageusia, and other taste disorders and their relationship to local and systemic causes.

Results

The authors found pertinent literature explaining the normal physiology of taste sensation, proposals for suggested new tastes, presence of gustatory receptors in remote tissues of the body, and etiology and pathophysiology of taste disorders, in addition to the valuable knowledge gained about gustatory disorders in the context of COVID-19. Along with olfactory disorders, taste disorders are one of the earliest suggestive symptoms of COVID-19 infection.

Conclusions

Gustatory disorders are the result of local or systemic etiology or both. Newer taste sensations, such as calcium and fat tastes, have been discovered, as well as taste receptors that are remote from the oropharyngeal area. Literature published during the COVID-19 pandemic to date reinforces the significance of early detection of potential patients with COVID-19 by means of screening for recent-onset taste disorders.

Practical Implications

Timely screening and identification of potential gustatory disorders are paramount for the dental care practitioner to aid in the early diagnosis of COVID-19 and other serious systemic disorders.

Acute Corneal Endothelial Graft Rejection With Coinciding COVID-19 Infection

PURPOSE

To report a case of acute corneal endothelial graft rejection with the concurrent onset of coronavirus disease 2019 (COVID-19) symptoms.

METHODS

Case report.

RESULTS

A 31-year-old African American woman with a history of asthma, sleep apnea, obesity (body mass index of 40), and bilateral keratoconus was noted to have acute corneal endothelial graft rejection 3 months after uncomplicated penetrating keratoplasty of the left eye. The patient developed dysgeusia and subjective fever on the same day as ocular discomfort, and she was subsequently diagnosed with COVID-19 with only these 2 classic symptoms of the viral infection.

CONCLUSIONS

Severe acute respiratory syndrome coronavirus 2 is known to cause conjunctivitis and has demonstrated transmissibility through ocular secretions. Acute immune and inflammatory dysregulations have been seen in cases of COVID-19 through various mechanisms. COVID-19 infection may potentially compromise ocular immune privilege contributing to acute corneal graft rejection.

Clinical features of COVID-19 and influenza: a comparative study on Nord Franche-Comte cluster

Clinical descriptions about influenza-like illnesses (ILI) in COVID-19 seem non-specific. We aimed to compare the clinical features of COVID-19 and influenza. We retrospectively investigated the clinical features and outcomes of confirmed cases of COVID-19 and influenza in Nord Franche-Comté Hospital between February 26th and March 14th 2020. We used SARS-CoV-2 RT-PCR and influenza virus A/B RT-PCR in respiratory samples to confirm the diagnosis. We included 124 patients. The mean age was 59 (±19 [19-98]) years with 69% female. 70 patients with COVID-19 and 54 patients with influenza A/B. Regarding age, sex and comorbidities, no differences were found between the two groups except a lower Charlson index in COVID-19 group (2 [±2.5] vs 3 [±2.4],p = 0.003). Anosmia (53% vs 17%,p < 0.001), dysgeusia (49% vs 20%,p = 0.001), diarrhea (40% vs 20%,p = 0.021), frontal headache (26% vs 9%,p = 0.021) and bilateral cracklings sounds (24% vs 9%,p = 0.034) were statistically more frequent in COVID-19. Sputum production (52% vs 29%,p = 0.010), dyspnea (59% vs 34%,p = 0.007), sore throat (44% vs 20%,p = 0.006), conjunctival hyperhemia (30% vs 4%,p < 0.001), tearing (24% vs 6%,p = 0.004), vomiting (22% vs 3%,p = 0.001) and rhonchi sounds (17% vs 1%,p = 0.002) were more frequent with influenza infection. We described several clinical differences which can help the clinicians during the co-circulation of influenza and SARS-CoV-2.

Self-reported anosmia and dysgeusia as key symptoms of coronavirus disease 2019

OBJECTIVES

To slow down the transmission of coronavirus disease 2019 (COVID-19), it is important to identify specific symptoms for effective screening. While anosmia/hyposmia and dysgeusia/ageusia have been identified as highly prevalent symptoms, there are wide geographic variations, necessitating the regional evaluation of the prevalence of the symptoms.

METHODS

A cross-sectional study was performed to evaluate the self-reported symptoms among adults (over 18 years old) who underwent COVID-19 tests at an ambulatory assessment centre. We identified 1,345 patients (102 positive and 1,243 negative) who visited the assessment centre between March 16 and April 15, 2020. We randomly sampled negative patients in a 1:3 ratio. The primary outcome was the prevalence of self-reported anosmia/hyposmia and dysgeusia/ageusia. Logistic regression was performed to evaluate the association between COVID-19 positivity and loss of smell and taste.

RESULTS

Fifty-six of 102 (50%) positive patients and 72 of 306 (23.5%) negative patients completed the survey. Anosmia/hyposmia and dysgeusia/ageusia were more prevalent among COVID-19 positive patients (41.1% v. 4.2%, p < 0.001 for smell and 46.4% v. 5.6%, p < 0.001 for taste). Anosmia/hyposmia and dysgeusia/ageusia were independently highly associated with COVID-19 positivity (adjusted odds ratios 14.4 and 11.4 for smell and taste, respectively).

CONCLUSION

In this Canadian study, smell and taste loss may be key symptoms of COVID-19. This evidence can be helpful in the clinical diagnosis of COVID-19, particularly settings of limited testing capacity.

Relationship between anosmia and hospitalisation in patients with coronavirus disease 2019: an otolaryngological perspective

OBJECTIVE

A study was carried out to evaluate the relationship between anosmia and hospital admission in coronavirus disease 2019 patients.

METHODS

The clinical data of 1534 patients with confirmed coronavirus disease 2019 virus were analysed. The study was conducted with medical records of 1197 patients (78 per cent). The basic characteristics of patients and symptoms related to otolaryngology practice were examined. The patients were divided into two groups according to their follow up: an out-patient group and an in-patient group.

RESULTS

The majority of patients presented with anosmia (44.2 per cent), dysgeusia (43.9 per cent) and fever (38.7 per cent). Anosmia was observed in 462 patients (47 per cent) in the out-patient group, and in only 67 patients (31.2 per cent) in the in-patient group. Younger age (odds ratio = 1.05, 95 per cent confidence interval = 1.03-1.06) and the presence of anosmia (odds ratio = 2.04, 95 per cent confidence interval = 1.39-3) were significantly related to out-patient treatment.

CONCLUSION

Anosmia could be a symptom in the clinical presentation of the coronavirus disease 2019 infection.

Psychometric properties of the Chinese version of the chemotherapy-induced taste alteration scale

PURPOSE

The chemotherapy-induced taste alteration scale (CiTAS) is a reliable and valid instrument to comprehensively assess patients' taste alterations in an easy way. We aimed to translate it and test its psychometric properties among Chinese cancer patients undergoing chemotherapy.

METHOD

A convenience sample of 227 cancer patients were recruited in a tertiary cancer hospital in Beijing. The Chinese version of the CiTAS (C-CiTAS) was developed via rigorous translation methods. An exploratory structural equation model (ESEM) was used to test its construct validity. Correlations between the C-CiTAS scores and the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 scores were calculated for convergent validity. The overall taste alterations scale (OTAS) score was used to test its discriminant validity. Reliabilities were also examined.

RESULTS

The majority of patients undergoing chemotherapy experienced minor to mild taste alterations. The current factor analysis results using the ESEM supported the original factor solution of the CiTAS, and no item of the CiTAS was dropped. The C-CiTAS demonstrated good construct validity, convergent validity and discriminant validity. The Cronbach's alphas of the C-CiTAS were 0.900 for the overall scale and from 0.570 to 0.857 for the four subscales. Its test-retest reliability was 0.815 (p < 0.01).

CONCLUSIONS

The Chinese version of the CiTAS is a reliable and valid instrument to evaluate cancer patients' Chemotherapy-induced taste alterations in China.

Prospective assessment of taste impairment and nausea during radiotherapy for head and neck cancer

Dysgeusia and nausea are common side effects observed in head and neck cancer patients treated with either exclusive radiotherapy or combined modality treatment. The aim of the present study was to prospectively evaluate dysgeusia, during treatment and follow-up, using the chemotherapy-induced taste alteration scale (CiTAS), a metrics based on 18-items exploring three dimensions (quantitative and qualitative changes in taste perception, and diet-related issues) identified through a four-factor analysis: decline in basic taste, discomfort, phantogeusia-parageusia, and general taste alterations. Moreover, we scored, according to Common Toxicity Criteria Adverse Events, nausea and other treatment-related toxicities. Since, ginger is traditionally used to prevent and/or treat nausea and vomiting, we prophylactically employed a ginger-based supplement named Naumix/Naugin (Gamfarma, Milan, Italy), to potentially mitigate both nausea and taste impairment. Using the CiTAS scale, we highlighted a progressive increase in all dysgeusia dimensions, peaking at the VII week of treatment and a subsequent partial late recovery. In particular, we observed a recovery for discomfort, phantogeusia-parageusia, and general taste alterations at 6 months. Grade 2 nausea, observed to be as low as 12.9% potentially due to the use of ginger, peaked at the III week of treatment. Finally, for patients experiencing nausea, the dysgeusia dimension of discomfort was also relevant.

Gustatory Function of Pregnant and Nonpregnant Women in a Tertiary Health Institution

Physiological changes in pregnancy may cause taste dysfunction. The aim of this study was to determine and compare gustatory function of pregnant women with nonpregnant women and also to investigate the effect of pregnancy on gustatory function. It was a case-control study of consecutive 70 healthy pregnant women (cases) and 70 healthy nonpregnant women (control). Participants scored their taste perception on a visual analogue scale (1-10) and their gustatory function was assessed using "taste strips" impregnated with graded concentration of sweet, sour, salty, and bitter taste substances applied on tongue surfaces. Subjective mean gustatory score, correct identification of taste in the strips and total taste strip (TTS) score were compared between both groups and analysis was done using appropriate statistics. The mean age of pregnant women (30.5 [3.9]) and controls (28.5 [6.6]) were comparable. Twenty-one (30%) pregnant women changed their diet in first trimester due to change in taste sensation. Almost all cases developed craving for spicy and salty foods and, aversions to fish, beans, and vegetables. There was a significant difference in the subjective rating of taste perception between the 2 groups ( P = .037). About 2.9% of pregnant women have hypogeusia. There was a significant difference between pregnant and nonpregnant women in sour taste ( P = .006; 2.90 [0.71] vs 3.92 [0.82]) and TTS ( P = .02; 27.50 [3.48] vs 29.21 [2.69]) scores, respectively. In conclusion, gustatory function was reduced in pregnancy compared to nonpregnant women and this led to dietary change in some pregnant women.

Safety and tolerability of prescription omega-3 fatty acids: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Omega-3 fatty acids [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] are widely recommended for health promotion. Over the last decade, prescription omega-3 fatty acid products (RxOME3FAs) have been approved for medical indications. Nonetheless, there is no comprehensive analysis of safety and tolerability of RxOME3FAs so far.

METHODS

A systematic review of randomized controlled trials (RCTs) was carried out based on searches in six electronic databases. The studies involving marketed RxOME3FA products were included, and adverse-effect data were extracted for meta-analysis. Subgroup analysis and meta-regression were conducted to explore the sources of potential heterogeneity.

RESULTS

Among the 21 included RCTs (total 24,460 participants; 12,750 from RxOME3FA treatment cohort and 11,710 from control cohort), there was no definite evidence of any RxOME3FA-emerging serious adverse event. Compared with the control group, RxOME3FAs were associated with more treatment-related dysgeusia (fishy taste; p = 0.011) and skin abnormalities (eruption, itching, exanthema, or eczema; p < 0.001). Besides, RxOME3FAs had mild adverse effects upon some non-lipid laboratory measurements [elevated fasting blood sugar (p = 0.005); elevated alanine transaminase (p = 0.022); elevated blood urea nitrogen (p = 0.047); decreased hemoglobin (p = 0.002); decreased hematocrit (p = 0.009)]. Subgroup analysis revealed that EPA/DHA combination products were associated with more treatment-related gastrointestinal adverse events [eructation (belching; p = 0.010); nausea (p = 0.044)] and low-density lipoprotein cholesterol elevation (p = 0.009; difference in means = 4.106mg/dL).

CONCLUSION

RxOME3FAs are generally safe and well tolerated but not free of adverse effects. Post-marketing surveillance and observational studies are still necessary to identify long-term adverse effects and to confirm the safety and tolerability profiles of RxOME3FAs.

[Gustation and dysgeusia.]

The enjoyment of tastes should be one of the greatest pleasures in life. Without the sense of taste, one cannot enjoy one's food. The result would then be poor appetite, eating less and weight loss. As the elderly population in Japan increases, the number of patients suffering from taste disorder has also increased. While changes in the ability to distinguish tastes are partly associated with advancing age, they occur moreover in response to secondary influences, such as the side effects of drugs, or the effects of some diseases including periodontal disease/oral infections, nervous disorders, nutritional impairment, and endocrine disorders. Some drugs affect sensitivity to taste by directly stimulating the taste receptors, not only altering the normal transmission process and cellular functions, but also altering the salivary flow. The reduction of salivary flow strongly correlates with a decline in taste perception. In cases of taste disorder, early detection and treatment are important because the appreciation of taste is vital for overall health and long life.

Sweet taste sensitivity in pre-diabetics, diabetics and normoglycemic controls: a comparative cross sectional study

BACKGROUND

Increasing prevalence of pre-diabetes is an emerging public health problem. Decrease in sweet taste sensitivity which can lead to an increase in sugar intake might be a factor driving them to overt diabetes. The aim of the present study was to assess the sweet taste sensitivity in pre-diabetics in comparison with diabetics and with normoglycemic controls.

METHODS

Forty pre-diabetics, 40 diabetics and 34 normoglycemic controls were studied. The three groups were matched for age, sex and BMI. The division into groups was based on their glycated hemoglobin levels. The detection and recognition thresholds were determined by the multiple forced-choice method using sucrose solutions prepared in ¼ log dilutions. The intensities of perceived sensations for a series of suprathreshold concentrations of sucrose solutions prepared in ½ log dilution were determined by rating on a visual analogue scale. Statistical analyses were performed by SPSS version 21.

RESULTS

The mean (SD) detection thresholds of diabetic, pre-diabetic and normoglycemic groups were 0.025 (0.01), 0.018 (0.01) and 0.015 (0.01) respectively with a significant increase in diabetic group compared to normoglycemic group (p = 0.03). The mean recognition thresholds were not different among the three groups. When the intensity ratings for suprathreshold concentrations of sucrose were compared between the three groups, for all suprathreshold concentrations tested, significant differences were observed across the four concentrations (p < 0.001) and between groups in suprathreshold ratings (p < 0.05). Further analysis showed that the diabetic group had significantly lower suprathreshold ratings than the normoglycemic group (p < 0.001). Although all mean suprathreshold intensity ratings of the pre-diabetic group were between the normoglycemic and diabetic groups, the differences were not significant.

CONCLUSIONS

This is the first study to demonstrate the sweet taste sensitivity in pre-diabetics. The findings of the present study do not support the hypothesis of decreased sweet taste sensitivity of pre-diabetics. However, the results confirm the previous findings of blunted taste response in diabetics. The observation of pre-diabetics having intermediate values for all taste thresholds and suprathreshold ratings warrants a future investigation with a larger pre-diabetic sample recruited with more specific screening criteria to test this hypothesis further.

[Bad aftertaste caused by pine nuts]

BACKGROUND

Dysgeusia caused by the consumption of pine nuts is not widely reported in the medical literature, although much is written about this condition on the Internet.

CASE DESCRIPTION

We present the case of a 46-year-old male who complained of metallic and bitter dysgeusia that started 2 days after the ingestion of approximately 70 grams of pine nuts. A literature search revealed only 3 case reports on this subject. In all cases including ours, the complaints began a few days after the ingestion of pine nuts and had spontaneously resolved after a week. No medical sequelae are known, but patients may suffer social consequences.

CONCLUSION

The cause of this condition is unknown. Possible causes include the presence of toxic or inedible components in the pine nuts. Physicians should be aware of this phenomenon in order to be able to reassure patients about this benign disorder.

[A case of sweet taste perception caused by lung cancer-related hyponatraemia]

BACKGROUND

Ageusia is known to occur in patients with lung cancer. The type of dysgeusia resulting in all food tasting sweet is, however, rare.

CASE REPORT

We describe the case of a 70-year-old woman presenting with an unpleasant sweet taste perception as the initial and only symptom of hyponatraemia. It was caused by the syndrome of inappropriate antidiuretic hormone (SIADH) secretion secondary to a small cell carcinoma of the lung. Treated by fluid restriction alone, the plasma sodium concentration increased and the sweet taste perception resolved. The exact pathophysiologic mechanism resulting in this type of dysgeusia is unclear to date.

CONCLUSION

It is important to be alert when the medical history reveals a relatively rare dysgeusia or ageusia; this could indicate a potentially serious underlying condition, including hyponatraemia caused by SIADH associated with a pulmonary malignancy.

Frequency and characteristics of taste impairment in patients with Parkinson's disease: results of a clinical interview

OBJECTIVE

Patients with Parkinson's disease (PD) frequently complain of a diminished sense of smell. Less frequently, they may complain of taste impairment. In the present study, we investigated the symptoms, frequency, and severity of taste impairment as well as smell impairment in PD patients and compared the results with those of age- and sex-matched healthy controls.

PATIENTS AND METHODS

We interviewed 285 PD patients (120 men, 165 women) without dementia or nasal problems. Control subjects comprised 61 (20 men, 41 women) healthy spouses of the PD patients. Alteration of smell and taste sense lasting more than 3 months was defined as abnormal.

RESULTS

One hundred and sixteen patients with PD complained of smell impairment and 26 complained of taste impairment. Only 5 controls complained of smell impairment, and no control subjects reported taste impairment. Taste impairment was more marked in patients with smell impairment. Impaired taste included diminished taste perception in 21 patients, altered sense of taste in 4 patients and burning mouth in 1 patient.

CONCLUSION

Taste as well as smell perception is impaired in patients with PD. The frequency of smell and taste impairments tended to increase with disease progression.