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.

[Impaired gustatory sensitivity of the tongue to table salt as a risk factor of arterial hypertension]

The study included 630 patients with verified diagnosis of arterial hypertension (AH) in whom 24 hr AP monitoring was performed, threshold gustatory sensitivity of the tongue to table salt (TGS) measured, and habit to add salt to the cooked food evaluated. Measurement of Na in daily urine of 442 patients was followed by estimation of salt consumption. The results were compared with those obtained in 100 patients with newly diagnosed AH. The control group comprised 288 subjects. TGS in AH patients was significantly higher than in controls and directly related to clinical features of the disease, high AP values, age, smoking habits, hypercholesterolemia, abdominal-type obesity, and hereditary predisposition. TGS positively correlated with daily urinary excretion of NaCl (r = 0.4-0.7; p < 0.05-0.01). High TGS decreased under effect of hypotensive therapy.

A primary large cholesterol cyst of the mastoid presenting with dysgeusia

The occurrence of postoperative secondary cholesterol cysts in the mastoid has been previously reported, however the occurrence of a primary large cholesterol cyst in the mastoid with bony destruction of the facial nerve has rarely been reported. The case report of a 17-year-old female patient with a primary large cholesterol cyst with dysgeusia is presented. Computed tomography and magnetic resonance imaging findings for the lesion distinguish a cholesterol granuloma, cholesteatoma and vascular tumor. The patient underwent a canal wall down mastoidectomy with mastoid obliteration. A dehiscent portion of the mastoid segment of the facial nerve was visible within the cavity; the gross finding of the facial nerve was edematous in appearance. Five years later, there has been no recurrence of disease.

Smell and taste dysfunction following minor stroke: a case report

Smell (olfactory) and taste (gustatory) are key senses in the regulation of nourishment and individual safety. Olfactory and gustatory dysfunctions have been infrequently reported together in patients following stroke (Landis et al., 2006; Leopold et al., 2006). This case report details two patients who experienced smell and taste dysfunction following minor stroke events. Symptoms reported included hyposmia (diminished sense of smell) and anosmia (complete loss of smell), and dysgeusia (distorted taste). Patients' sense of smell and taste were assessed in an ambulatory care stroke prevention clinic eight months following their strokes. Patient A presented with minor stroke due to a lesion in the anterior circulation, patient B with a lesion in the posterior circulation. Both patients reported intense olfactory and gustatory dysfunction immediately following their strokes. Examination revealed a general inability to detect subtle odours and the ability to identify only 'sweet' tastes for both patients. In addition, both patients reported heavily salting or sweetening their food to mask the distorted and unpleasant taste, which also impacted comorbid conditions such as hypertension and diabetes. Patients and their spouses reported a decrease in their appreciation of family-related activities due to the patients' olfactory and gustatory dysfunction. Patients reported weight loss, lack of energy and strength, likely due to poor nutrition. Olfactory and gustatory dysfunctions are potentially deleterious outcomes following minor stroke and should be assessed by health care professionals prior to patient discharge. Assistance may be required to promote the health and well-being of patients and their carers if smell and taste are impacted by the stroke event.

Apolipoprotein E epsilon4 genotype and gender: effects on memory

OBJECTIVE

Episodic recognition memory for odors and visual was assessed in apolipoprotein E (ApoE) epsilon4-positive and epsilon4-negative men and women diagnosed with Alzheimer disease (AD) and a healthy age- and gender-matched comparison group.

METHODS

A total of 38 AD patients and 38 age- and gender-matched healthy older adults completed a recognition memory task involving three categories of stimuli: odors, faces, and symbols.

RESULTS

In the healthy comparison group, men who were epsilon4 negative outperformed epsilon4-positive men in recognition memory for odors and committed fewer false-positive errors. However, there were no significant differences between epsilon4-negative and epsilon4-positive women in the comparison group. No significant gender or ApoE status differences were detected in recognition memory for faces or symbols in the comparison group. In patients with AD, epsilon4-negative women outperformed epsilon4-positive women in recognition memory for odors and committed significantly fewer false-positive errors. However, there were no significant differences between epsilon4-positive and epsilon4-negative men. There were no significant gender or ApoE status differences in recognition memory for faces or symbols in AD patients.

CONCLUSION

The results demonstrate that recognition memory for olfactory stimuli may be particularly impaired in healthy older men with the epsilon4 allele. In patients with AD, odor memory impairments may be less severe in women who are negative for the epsilon4 allele. The results offer new insight into how recognition memory is affected by gender, the epsilon4 allele, and the modality of the stimulus to be remembered in healthy older adults and patients with AD.

Lack of support for the inability to taste phenylthiocarbamide as an endophenotypic marker in patients with schizophrenia and their first-degree relatives

OBJECTIVE

This study sought to replicate recent findings that both patients and relatives are significantly more likely to be phenylthiocarbamide (PTC) nontasters than healthy controls, and that within the patient group, nontasters have more severe positive and/or negative symptoms than tasters. Associations between PTC-tasting status and olfactory identification scores also were examined.

METHOD

PTC perception and olfactory identification were assessed in 48 patients with schizophrenia or schizoaffective disorder, 28 first-degree relatives, and 32 healthy volunteers.

RESULTS

The three groups did not differ in PTC taste sensitivity. Findings did not change after: a sensitivity analysis that re-categorized participants who "possibly" tasted PTC, excluding Caucasian participants, or restricting the sample of patients to only those with schizophrenia. Among the patients, tasters and nontasters did not differ with regard to positive, negative, or general psychopathology symptoms. In the combined sample and the three groups separately, there were no associations between PTC-tasting status and olfactory identification scores.

CONCLUSIONS

This study, conducted specifically as an attempt to replicate previously reported findings, failed to provide support for PTC perception as an endophenotypic marker for schizophrenia. Further research is warranted.

Unpleasant sweet taste: a symptom of SIADH caused by lung cancer

A 56 year old woman with large cell lung carcinoma complained of an unpleasant sweet taste (dysgeusia). She developed hyponatraemia caused by the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Dysgeusia disappeared when serum sodium normalised and recurred when hyponatraemia relapsed. Dysgeusia was the initial and only symptom of SIADH in this case.

Diagnosis of systemic sarcoidosis prompted by orofacial manifestations

BACKGROUND

Sarcoidosis is a multifactorial systemic inflammatory disorder of unknown origin characterized by many potential signs and symptoms, as well as by the presence of noncaseating granulomas in the organs involved. Sarcoidosis also may manifest in the oral and maxillofacial region.

CASE DESCRIPTION

The authors describe a patient with xerostomia, dysgeusia, oral burning, xerophthalmia and bilateral parotid enlargement. She was diagnosed as having systemic sarcoidosis on the basis of the histologic findings of a biopsy of the labial minor salivary gland, as well as subsequent diagnostic evalutons.

CONCLUSION AND CLINICAL IMPLICATIONS

Enlargement of major salivary glands may be the first sign of sarcoidosis in a patient with few other symptoms or clinical findings suggestive of the disease. This case emphasizes the importance of including sarcoidosis in the differential diagnosis of bilateral parotid swelling associated with xerostomia. It also highlights the dentist's potential role in the diagnosis and dental treatment of patients with systemic sarcoidosis.

A case of Cronkhite-Canada syndrome with taste disturbance as a leading complaint

Cronkhite-Canada syndrome was first described in 1955. The clinical features of this rare syndrome of unknown etiology include nonhereditary gastrointestinal polyposis together with diarrhea, nail dystrophy, alopecia, and hyperpigmentation of the skin. This syndrome has been divided into five clinical types based on initial symptoms. We describe a case of Cronkhite-Canada syndrome presenting with taste disturbance as the major symptom, present a comprehensive review of the literature concerning this rare syndrome, and suggest therapeutic treatment options.

Simple Partial Seizures with Hemisensory Phenomena and Dysgeusia: An Insular Pattern

Insular seizures are rarely described, in part owing to the complex anatomy of this brain region. We present a patient with simple partial seizures, recorded intracranially, originating in the right insula and characterized by dysgeusia and contralateral somatosensory phenomena. This rare clinical pattern seems to be characteristic of the insula and may be undetectable with surface EEG.

Detection and recognition thresholds to the 4 basic tastes in Mexican patients with primary Sjögren's syndrome

BACKGROUND

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease characterized by inflammatory lymphocytic infiltration of the salivary glands, leading to dryness of the mouth (xerostomia). It has been postulated that xerostomia is the preceding stage for the development of alterations in taste acuity (dysgeusia) in this type of patients.

OBJECTIVES

To determine detection and recognition thresholds to the 4 basic tastes (sweet, salty, sour and bitter) in pSS patients and compare them to a control group. To determine if the long-term consumption of chile peppers and spicy Mexican diets had an effect on the taste perception and acuity of the pSS patients.

SETTING

This study was done in the Department of Food Science and Technology of the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (INCMNSZ), a third-level hospital in Mexico City.

SUBJECTS

The patient group consisted of 21 Mexican females (mean +/- s.d., age: 53.1 +/- 9.8 y) diagnosed with pSS (time of duration of the disease, 8.6 +/- 6.6 y, median 7 y, range 1-25 y) who were recruited at the outpatient service of the Department of Immunology and Rheumatology of the INCMNSZ. The control group consisted of 20 healthy nonsmokers age-matched Mexican women (50.3 +/- 11.9 y) most of them personnel of the INCMNSZ, and some friends and nonblood relatives to the patients (sisters-in-law) who volunteered to participate in the study.

INTERVENTIONS

Detection and recognition thresholds were determined by the method of least noticeable differences on three occasions during three nonconsecutive days. Saliva production was determined by Saxon's test on two separate occasions.

RESULTS

Although saliva production was severely reduced in pSS patients (1.35 +/- 0.55 ml/2 min, P<0.001) compared to controls (6.26 +/- 2.41 ml/2 min), all subjects recognized the 4 basic tastes when these were tested at suprathreshold concentrations. The detection thresholds for the sweet, sour and bitter tastes were higher in pSS patients, as well as the recognition thresholds for the salty, sour and bitter tastes. A relationship between time of evolution of the disease and saliva production with individual thresholds could not be established.

CONCLUSIONS

pSS patients exhibited different degrees of dysgeusia depending on the taste being studied, that is, they were mildly dysgeusic for the sweet and salty tastes and clearly dysgeusic for the sour and bitter tastes. Although both pSS patients and controls had consumed 'typical Mexican diets' their entire lives, our results showed that the consumption of chile peppers and spicy foods did not have any effect on the taste perception and acuity of the pSS patients.

Dysgeusia due to an orthodontic wire: a case report

A 14-year-old female developed gustatory disorder due to an orthodontic wire having pierced the right trigonal retromolar. The patient's complaints included traction pain on the right lower jaw, numbness on the right front half of the tongue and hypogeusia with the exception of sweet tastes. Possible causes of dysgeusia in this case were: (i) direct mechanical compression of a gustatory nerve by the orthodontic wire; and (ii) disturbance of blood supply to a gustatory nerve by edema that developed in nerve tissues around the wire. The patient's retention of a normal threshold for the recognition of sweet tastes is not fully understood.

Electron microscopic observations of glossal circumvallate papillae in dysgeusic patients

A number of reports have been published describing the ultrastructure of normal taste buds but few have discussed their pathology, particularly in patients with gustatory abnormalities. We therefore conducted an electron microscopic study of biopsy specimens of glossal circumvallate papillae from patients with dysgeusia. We found depletion of microvilli and dense substance in the taste pores, vacuolation and hyaline degeneration of the taste bud cells and condensation of nuclear material and cytoplasm in cells of indeterminate histological type. In one patient with idiopathic dysgeusia, disruption of subsurface cisternae contiguous with the nerve endings was evident in Type II cells. In another patient, who had undergone radiotherapy, the number of cored vesicles in Type III cells was reduced.

[Semiologic study of chronic perennial and permanent paranasal sinus dysfunction. Prevalence of symptoms]

Rhino-sinus dysfunction is associated with several symptoms: nasal obstruction, anterior and posterior rhinorrhea, episodes of sneezing, painful or heavy feeling in the face, taste and smell disorders. Certain manifestations have an impact on the pharynx, the larynx or the tracheobronchial tree. This prospective study was conducted in 449 consecutive patients who consulted over an 18-months period from November 1995 to May 1997. The objective was to determine the symptom pattern, main disease of the nasal cavities and paranasal sinuses which were involved: chronic rhinitis, anterior sinusitis, bilateral and symmetric pansinusitis with or without nasosinus polyps. In the first part of the study, the frequency of different symptoms were determined for the main nasosinus diseases. Statistical analysis of the correlations between symptoms and diseases provided a specific approach to symptoms.

Taste and smell in familial dysautonomia

Familial dysautonomia (FD) is one of the classic diseases characterised by taste and smell abnormalities. However, these typical features are based on data obtained from two separate crude studies published in 1964. In the present study psychophysical-cognitive and reflex-like facial-behavioral responses to taste and smell, in nine patients with FD and 15 healthy controls, were recorded. Five taste stimulants were presented to both study groups, while a selection of common household odors was used for FD patients only. The patients with FD showed a markedly higher incidence of recognition failures for salty, bitter, sweet, and water stimuli than the controls, but rate of recognition of sour stimuli was almost identical in the two groups. Estimates by the subjects on a hedonic scale of 0 to 10 and facial display in FD indicated a relatively normal sensitivity to sour stimuli and to a lesser extent to bitter stimuli. Water, sweet, and salty stimuli evoked non-discriminatory responses. These findings indicate specific dyageusia rather than general ageusia. Smell was found to be normal. In children with taste and smell impairment, a systematic evaluative approach may help in planning palatable diets for adequate and comfortable nutrition.

From the aerospace medicine residents' teaching file

A pilot presented with a 2-month history of dysgeusia following treatment for sinusitis. This was accompanied by a 30-lb weight loss due to the abnormal taste of most foods. An extensive evaluation failed to demonstrate a cause for the malady. The clinical course and diagnostic evaluation were consistent with a diagnosis of idiopathic dysgeusia. The clinical presentation, evaluation, and diagnosis of a pilot with dysgeusia are discussed.

Clinical and physiological investigations in patients with taste abnormality

The cause of taste abnormality was investigated in 25 patients with decreased taste sensation (hypogeusia group) and 14 patients with abnormal taste sensation (dysgeusia group) by examining taste threshold, salivary flow rate, Candida cell culture, and laboratory examination of peripheral blood. The cause of hypogeusia was identified as iron deficiency in 7 patients, oral candidiasis in 6, hyposalivation (xerostomia) in 6, and psychiatric distress in 3, and could not be determined in 3 (idiopathic). Dysgeusia was associated with psychiatric distress in 8 patients, oral candidiasis in 3, drug medication in 2, and hyposalivation in 1. In the hypogeusia group, the decreased taste sensation generally corresponded with elevated taste thresholds, which decreased along with improvement of the decreased taste sensation in all except the 3 patients with psychiatric etiology and 2 of the 3 patients with idiopathic etiology. In contrast, no elevation or depression of taste thresholds were observed in the dysgeusia group, and the abnormal taste sensation did not disappear in most cases; however, drug-induced dysgeusia improved completely within 2 months after cessation of the drug administration. The serum copper and zinc levels were not decreased in any patient, but a decreased serum iron level was observed in 7 patients. Based on these results, it is concluded that abnormal taste sensation may be induced by many oral and systemic disturbances and that hypogeusia, which may be induced by deficiency of iron but not of zinc or copper, is usually accompanied by elevation of taste thresholds, while dysgeusia is not.

[Disorders of the sense of smell and taste]

Disorders of olfaction and taste are infrequent, but a complete loss of smell or taste reduces the quality of life significantly. The sensitivity of human olfaction is remarkable, even for specific stimuli: Just a few molecules are enough to induce the correct identification of sterilised and ultraheated milk. Olfaction and taste are called 'chemical senses' because in both cases the adequate stimulus consists of molecules that bind to receptors of the sensory cells. The perceptions of smell and taste are often combined. Taste differentiates only four qualities: sweet, sour, salty, and bitter. The typical flavor of food or drink is detected by olfaction. Disturbances of olfaction can be due to respiratory disorders such as nasal polyps, a deviation of the nasal septum or chronic sinusitis. Such conditions can reduce airflow through the olfactory cleft at the roof of the nasal cavity. They can be corrected by modern endoscopic surgery of the nose. Epithelial disorders involving the sensory cells are most often caused by viral infections (influenza-anosmia) or toxic destruction of the sensory epithelium (solvents or gases). Epithelial disorders can be cured only rarely by any treatment. Corticosteroids, zinc, and vitamin A are tried frequently. Neural disorders occur after frontobasal trauma and during neurological diseases such as Parkinson's or Alzheimer's disease. Disorders of olfaction can be an early sign of such neurological diseases and sophisticated examination of this sense can contribute to their early diagnosis. However, no specific treatments have yet been identified. Disorders of taste can be due to toxic, chemical or inflammatory damage to the sensory cells of the tongue.(ABSTRACT TRUNCATED AT 250 WORDS)

Early detection of diabetic patients at risk of developing degenerative complications using electric gustometry: a five-year follow-up study

OBJECTIVES

Taste impairment has been reported during the course of diabetes. Although a degenerative mechanism has been suspected, the natural history of taste disorders in diabetes remains unknown. The purpose of this study was to describe the five-year evolution of electric gustometry in diabetic patients compared to healthy control subjects and with reference to degenerative complications of the disease.

METHODS

Electrogustometry was studied initially and after 5 years in 73 diabetic out patients and 25 control subjects. None of them had any known cause of taste impairment other than diabetes. Diabetic patients and control subjects did not differ for demographic data and confounding factors.

RESULTS

After five years, the electrogustometric threshold (EGT) significantly increased (51 +/- 6 vs 95 +/- 11 microA; p < 0.001), whereas slight changes occurred in control subjects (23 +/- 4 vs 25 +/- 5 microA; NS). Frequency of electric hypogeusia (EGT > or = 100 microA) increased from 11 to 46% in diabetic patients (p < 0.001), but did not vary in control subjects (4%). EGT was not strongly associated with individual factors such as blood pressure, tobacco and alcohol consumption, but correlated with age (p < 0.001). In the diabetic group, higher EGT were observed in patients treated with insulin (p < 0.001). EGT and its changes were associated with degenerative complication (p < 0.001), but neither with metabolic control, nor with duration of diabetes. Using multivariate analyses, the strongest associations were found with peripheral neuropathy and microalbuminuria (28 to 45% of variance explained; p < 0.001). The predictive value of initial hypogeusia on neuropathy at follow-up was 88% for a positive test and 63% for a negative one.

CONCLUSIONS

These results suggest that the taste nerves transduction function is impaired during the course of diabetes. This impairment is associated with an increased occurrence of degenerative complications, leading to suspect a similar pathophysiological mechanism. Electric gustometry could be an interesting test for early screening for diabetes complications.

Clinical applications and mechanism of intravenous taste tests

It is well known that there are two ways to measure human blood circulation time: the arm-to-lung and the arm-to-tongue method. The decholin (20% dehydrocholic acid) test is usually used to measure the arm-to-tongue circulation time. In this study, this procedure was used to examine taste function. Findings on the clinical application of this intravenous taste test using decholin and a study on the mechanism of venous taste perception are reported here. The following method was used: Five ml of 20% decholin were injected into the right cubital vein over a 10-sec period and the latent time, the duration, the quality of the taste sensation and the region of the tongue where the taste appeared were noted. The results were as follows: 1) In dysgeusic subjects, the latent period was longer, and the duration of the taste sensation was shorter than in normal subjects (p is less than 0.01, p is less than 0.05). 2) Some of the dysgeusic subjects perceived the taste as other than bitter; their prognosis of taste dysfunction tended to be worse than that of other subjects. 3) Some of the dysgeusic subjects perceived the taste in regions of the tongue other than the bilateral edges or over the entire tongue; their prognosis of taste dysfunction tended to be worse than that of other subjects. 3) Some of the dysgeusic subjects perceived the taste in regions of the tongue other than bilateral edges or over the entire tongue; their prognosis tended to be worse than that of other subjects. In addition, photofluorograms of the tongue were taken to clarify the mechanism of intravenous taste; the time needed for fluorescence to appear in the fungiform papillae and their diffusion form in the papillae were observed and investigated.

Dysosmia and dysgeusia presenting as depression

Disorders of taste and smell are underrecognized and often misdiagnosed. Two cases are described in which patients mistakenly thought to suffer from depression actually had unnoticed drug-induced dysosmia and dysgeusia. Also reviewed are psychiatric, neurologic, and medical disorders and drugs that cause abnormalities of taste and smell, and some behavioral aspects of food aversions. Three groups, all of whom may superficially appear depressed, must be distinguished from each other: 1) patients with dysosmia or dysgeusia, 2) patients with primary neuropsychiatric illness with olfactory or gustatory hallucinations, and 3) patients with conditioned taste aversions.

A classification of dysgeusia

The results of this study indicate that patients with dysgeusia can be classified into groups on the basis of the number and kinds of foods and beverages they perceive as distorted. Furthermore, a relationship between this classification and weight loss has been demonstrated, suggesting that caloric intake is decreased, particularly in patients with Type III and IV. The symptoms of dysgeusia worsened in 41% of all patients. These patients had sought medical help more quickly than any other patients with dysgeusia. An elevation in dysgeusia type (increase in severity) occurred in only a small number of patients, and no patient exhibited any improvement in dysgeusia once it occurred. Specific types of foods and beverages were commonly distorted in these patients. To characterize these abnormalities, we used six common food groups. On occasion, patients would eliminate an entire food group from their diets; if the nutrients contained in these foods could not be obtained from other dietary sources or if the food aversion persisted long enough (16), these patients could develop nutritional deficiencies. A nutritional history, using a standard form, was selected as the method for collecting data. Classification might have been even more accurate if a standardized food array had been used as part of this study. Indeed, we have developed such an array consisting of 120 food items and have since used it in conjunction with a diet history to evaluate patients with dysgeusia. Preliminary results confirm its usefulness in the classification described in this article.(ABSTRACT TRUNCATED AT 250 WORDS)