A Nationwide survey of safety protocols and chemosensory assessments by Japanese clinicians pre- and post-COVID-19 pandemic.

OBJECTIVE: There has been an increase of attention and awareness of smell and taste loss due to the impact of COVID-19. However, little is known about the influence of COVID-19 on the number of psychophysical tests performed, the timing of these tests, or the protection protocols employed to protect against virus transmission. This study aimed to explore the changes in examination approaches, types of tests employed, and safety measures adopted by clinicians before and after the COVID-19 pandemic. METHODS: A survey was distributed to 404 institutes of the Oto-Rhino Laryngological Society of Japan, consisting of otolaryngologists working in university hospitals, general hospitals, and private clinics. The anonymous online survey contained questions related to safety measures and chemosensory assessments performed before and after the COVID-19 pandemic. Specifically, participants were queried on the number and types of examinations conducted, the type of examiners who performed them, the timing of tests in suspected and non-suspected COVID-19 cases, modifications made due to the pandemic, and the protective measures adopted during chemosensory examinations. RESULTS: Of the 201 respondents, representing a 50 % response rate, 49 % were from general hospitals, 48 % from university hospitals, and 3 % from private clinics. The study found a slight decrease in the overall number of chemosensory tests conducted post-COVID-19. In terms of who performed the test, there were no differences pre- and post- COVID-19. Most examinations (52-68 %) for suspected COVID-19 cases were performed 1-2 months after the onset of symptoms. Modifications in testing rooms and personal protective equipment (PPE) were reported by the majority of institutions post-pandemic. While different examination rooms or PPE were not commonly used based on a patient's previous COVID-19 diagnosis, changes were observed in testing practices. Most examinations were conducted in rooms with windows or fans, and PPE usage was high; surgical masks, eye visors or face shields, and disposable gloves being commonly used. Virus transmission from patient to examiner was reported in only one case during T&T olfactometer examination. CONCLUSION: We investigated the impact of the COVID-19 pandemic on the number of olfactory and gustatory tests performed, the type of examiner, the examination room, and the use of PPE and found no significant difference before and after the COVID-19 pandemic on these factors. Adherence to a protection protocol involving the proper use of PPE in controlled environments enabled the continuation of olfactory and gustatory tests during the pandemic.

Diagnosis and treatment of taste disorders in Japan.

Though 270,000 patients with complaints of taste abnormalities visited medical institutions annually in 2019 survey, there are no drugs for the treatment of taste disorders that are covered by health insurance in Japan. In the survey, the number of patients with taste disorders was correlated with age, and the need for medical treatment for taste disorders is expected to increase in the future because of the super-aging society. The pathophysiology of taste disorders varies widely. There is an obvious need to decide the site and the causes of the disorder and understand the mechanism, by performing various examinations. It needs to first adjust the causative systemic diseases and medications in the treatment for taste disorder. Damage of taste cells due to zinc deficiency is the main pathophysiological mechanism of taste disorders, and zinc supplementation is a standard treatment in Japan. Oral zinc therapy is the treatment for taste disorders due to zinc deficiency or idiopathic taste disorder; though a double-blind study was conducted, it was considered low-level evidence in a clinical review. In Japan, the off-label use of polaprezinc for taste disorders was approved in 2011, and zinc acetate hydrate was approved for hypozincemia in March 2017, making it easier to use oral zinc therapy in general. In some cases, psychotherapy or herbal medicine therapy has been used with remarkable success, although its effectiveness has not been clearly tested. It might be expected to offer some help to patients. In the treatment of elderly patients with taste disorders, physicians need to consider the difference between "age-related changes in taste in healthy people" and "taste disorders in elderly persons", and they should separate them. Aggressive treatment is desirable regardless of age, because no significant difference in the efficacy of various treatments was found between patients older and younger than 65 years.

A clinical survey on patients with taste disorders in Japan: A comparative study.

OBJECTIVE: To investigate changes in the clinical state of taste disorders between 1990, 2003, and 2019 using the same methodology as that in previous studies. MATERIALS AND METHODS: In June 2019, we mailed a questionnaire to 1100 otolaryngologists belonging to the Japan Society of Stomato-pharyngology and investigated three question categories: "Institution", "Number of patients for 3 months", and "Treatment". In addition, we analyzed some results by the class of institution. RESULTS: The rate of patients who complained of taste disorders in the 2019 survey (220/100,000 persons/year) was twice that of the 1990 survey (110/100,000 persons/year), and slightly higher than that of the 2003 survey (192/100,000 persons/year). The rate of female patients was higher than that of male patients in all age groups. The number of patients was correlated with age up to 70 years of age in both genders. The rates of performing taste tests to assess taste function in the 2019 survey were significantly decreased compared with a 2003 survey (electrogustometry: p<0.001, filter paper disk method: p<0.05 in university). The rate of examination of the serum zinc in the 2019 survey was increased compared with the 1990 survey (p<0.001). Zinc oral therapy was used for the treatment of taste disorders in 239/299 (79.9%) patients/institutes for 3 months. In addition, 213 institutions (69.6%) answered that zinc oral therapy was efficacious for taste disorders. CONCLUSION: The patients who complained of taste disorder have increased. The zinc administration is an appropriate clinical treatment for taste disorders in Japan. To enhance treatment for taste disorders, simpler methods for assessing taste function need to be developed, and the pathological mechanisms of taste disorders other than zinc deficiency need to be clarified.

Earlier recovery of lingual dysfunction after middle ear surgery in pediatric versus adult patients.

OBJECTIVES: It is generally thought that the recovery of damaged chorda tympani nerve (CTN) function after middle ear surgery is different in pediatric patients from that in adult patients. The purpose of this study was to investigate the changes and the progress of taste and somatosensory functions of the tongue after middle ear surgery in pediatric patients compared with those of adult patients. STUDY DESIGN: Prospective study. METHODS: Fifty-nine pediatric patients and 106 adult patients underwent middle ear surgery. Taste and somatosensory functions of the anterior tongue, the so-called CTN functions, were assessed using electrogustometry (EGM), a 2-point discriminator, an electrostimulator, and a questionnaire before and 2 weeks and 6 months after surgery. RESULTS: Two weeks after surgery, there was no significant difference in the incidence of dysgeusia and abnormal EGM thresholds between the patient groups. The incidence of tongue numbness was significantly lower in pediatric patients than in adult patients regardless of CTN manipulation. Although the lingual somatosensory thresholds of adult patients were significantly increased, those of pediatric patients were not increased. Six months after surgery, the incidences of dysgeusia and an abnormal EGM threshold were lower in pediatric patients than in adult patients. Tongue numbness disappeared, and the thresholds of lingual somatosensory tests returned to normal in most pediatric patients. CONCLUSION: Not only taste function but also lingual somatosensory function was damaged after middle ear surgery even in pediatric patients. Pediatric patients complained of tongue numbness less frequently and showed earlier recovery than adult patients. LEVEL OF EVIDENCE: 2 Laryngoscope, 130:1016-1022, 2020.

Change of somatosensory function of the tongue caused by chorda tympani nerve disorder after stapes surgery.

OBJECTIVES: Patients after middle ear surgery often complain of taste disturbance and a lingual numbness. The purpose of this study was to objectively assess changes in the somatosensation of the tongue and taste function in patients undergoing stapes surgery. STUDY DESIGN: Prospective study. METHODS: Symptoms of taste disturbance and tongue numbness after surgery were investigated before and after surgery in 41 patients (13 males, 28 females; mean age 41.8 years) who underwent stapes surgery. Twenty-eight patients (9 males, 19 females; mean age 43.1 years) underwent sensory and taste function tests before and after surgery. Sensory function of the tongue was measured at the operated side and the nonoperated side using the 2-point discrimination test and an electrostimulator test. Taste function was assessed with electrogustometry (EGM). RESULTS: The chorda tympani nerve (CTN) was gently touched or stretched in all patients. Postoperative thresholds on the operated side were significantly higher than preoperative thresholds in all tests in the patients who underwent all three kinds of tests. Tongue somatosensory symptoms improved significantly earlier than the taste disturbance postoperatively, and the sensory thresholds returned to the baseline along with recovery of symptoms. CONCLUSION: These findings suggest that dysfunction of the CTN occurred following surgery even when the CTN was preserved, and that the sensory nerve threshold of the tongue correlated with the symptom of lingual numbness. The CTN may play a role not only in taste function but also in the somatosensory function of the tongue. LEVEL OF EVIDENCE: 4. Laryngoscope, 128:701-706, 2018.

[Time course of changes in gustatory function test results and subjective symptoms, and predictive factors for response in patients with taste disorder receiving 24-week zinc replacement treatment].

In a taste disorder, an agreement between patients' complaints and gustatory function test results is not necessarily found both at the initial hospital visit and during the course of treatment; therefore, it is difficult to assess treatment responses and review treatment strategies based on the assessed treatment responses. The present study investigated the time course of changes in disc gustometry results and subjective symptom scores measured at 4-week intervals in 44 patients with a taste disorder who were considered eligible for zinc replacement treatment and who received polaprezinc at a dose of 150 mg/day (equivalent to a 34 mg/day dose of zinc) for up to 24 weeks. The study also examined the potential differences in treatment outcomes according to the predictive factors for response such as patient background and assessed disc gustometry results during the course of treatment. Results indicated that disc gustometry results and subjective symptom scores showed different time courses of changes. The response rate as measured by disc gustometry was 47.7% at week 12 of treatment, and showed a subsequent slow increase to 56.8% at week 24. On the other hand, subjective symptom scores showed a time-proportional improvement up to week 24. Among the patients included in the present study, a clear difference was found according to the presence or absence of an improving trend as determined by disc gustometry at week 12 of treatment, although there were no differences in ultimate treatment responses, including categories of taste disorder, according to patient background. Patients showing a trend toward improvement had significantly better treatment responses in terms of both ultimate response rates and subjective symptom scores, whereas patients showing no trend toward improvement were less likely to respond to the subsequent 12-week continued treatment.

Trigeminal and taste sensations of the tongue after middle ear surgery.

OBJECTIVE: To establish clinical tests for measurement of trigeminal sensitivity on the human tongue and objectively assess changes in oral trigeminal sensitivity and taste ability after chorda tympani nerve (CTN) injury. STUDY DESIGN: Prospective study. SETTING: University hospital. PATIENTS: One-hundred and twenty-six patients with unilateral middle ear diseases who underwent primary middle ear surgery. MAIN OUTCOMES AND MEASURES: Trigeminal sensation was measured each operated side as well as nonoperated side both before and 14 days after surgery using 3 kinds of tests: Semmes-Weinstein sensory test (SW test), 2-point discrimination test, and the electrostimulator test. Taste function was assessed with electrogustometry (EGM) similarly. RESULTS: The patients which the CTN was not touched (n = 6) showed no differences between preoperative and postoperative thresholds in any tests. In the patients with sectioned CTN (n=30), postoperative thresholds on the operated side were significantly higher than preoperative thresholds on the electrostimulator test, 2-point discrimination test, and EGM. In the patients with manipulated but not sectioned CTN (n = 90), postoperative thresholds were significantly higher than preoperative thresholds on the electrostimulator test and EGM. The patients with manipulated but not sectioned CTN and abnormal EGM postoperative thresholds (n = 48) showed that postoperative thresholds were significantly higher than preoperative thresholds in all tests. CONCLUSION: These findings suggest that the electrostimulator test was most useful to objectively assess small changes of trigeminal sensation among the 3 tests. The finding that trigeminal sensitivity of the tongue deteriorated on the operated side after CTN injury suggests that CTN function affected both taste sensation and trigeminal sensation of the tongue.

[Clinical analysis of 1059 patients with taste disorders].

Taste disorders are caused by several factors, and there have been few reports concerning the clinical course of taste disorders. In this study, patients with taste disorders were classified into 10 groups according to causes, and they were retrospectively studied in terms of therapeutic effects. In total, 1059 patients (412 men and 647 women, mean age: 60.0 years) who complained of taste disorders were reviewed in our clinic. The patients were asked detailed questions about their history of symptoms, and their emotional status was assessed using a self-rating depression scale. In all subjects, taste functions were measured by electrogustometry (EGM) and filter paper disks (FPD). The grades of their symptoms were assessed with a visual analogue scale (VAS). In addition, the levels of serum iron, copper, and zinc were examined. The patients were treated with zinc sulfate, polaprezinc, iron preparation, herbal medicine, and minor tranquilizers according to the factors causing the taste disorders. The most frequent cause was idiopathic taste disorder (192 cases, 18.2%), the second was psychogenic (186 cases, 17.6%), and the third was drug-induced (179 cases, 16.9%). The recovery rate of the symptoms was 64/92 (70.2%) in post-common cold, 31/35 (88.6%) in iron deficiency, and 85/116 (73.3%) in zinc deficiency. In these groups, the rates of recoveries were better than in the other groups. The recovery period in drug-induced taste disorders was approximately twice as long as the recovery period in the other groups. In the patients who were able to start treatment within 6 months from the onset of taste disorder, the recovery rate was significantly higher and the therapeutic period was significantly shorter than in those who had the disorders for more than 6 months (p<0.05, respectively).

Preoperative assessment of taste function in patients with middle ear disease.

OBJECTIVE: To identify differences in taste function among patients with chronic otitis media, cholesteatoma, and noninflammatory disease before middle ear surgery. STUDY DESIGN: Retrospective analysis. SETTING: Tertiary referral hospital. PATIENTS: Two hundred thirty ears underwent primary middle ear surgery from January 2006 to December 2010. The subjects consisted of 84 men and 146 women with ages ranging from 20 to 60 years (mean, 43.9 yr). There were 95 ears with chronic otitis media, 61 ears with pars flaccida retraction-type cholesteatoma, 22 ears with pars tensa retraction-type cholesteatoma, and 52 ears with noninflammatory diseases such as otosclerosis and ossicular anomalies. MAIN OUTCOME MEASURE: The patients underwent taste testing using electrogustometry and the filter paper disk method in the regions controlled by the chorda tympani nerve. RESULTS: None of the patients complained of taste dysfunction before middle ear surgery. Among the 4 groups, the patients with pars tensa retraction-type cholesteatoma displayed the highest electrogustometry threshold. The filter paper disk method did not detect any significant differences among the 4 groups. CONCLUSION: Our findings suggest that the filter paper disk scores of all taste qualities (sweet, salty, sour, and bitter tastes) are not deteriorated preoperatively during chronic inflammation in the middle ear and that taste function is affected most in patients with pars tensa retraction-type cholesteatoma.

Utility of real-time diagnosis using contact endoscopy for oral and lingual diseases.

OBJECTIVE: In this study, we prospectively investigated the diagnostic accuracy of CE findings in oral and lingual diseases. METHODS: Between January 2004 and December 2009, CE was used to examine 66 patients with oral and lingual diseases at Hyogo College of Medicine Hospital. Blood vessel networks and superficial cell layers in the mucosal epithelium of normal and lesion sites were observed after staining with 1% methylene blue. Endoscopic diagnoses (CE diagnosis) were compared with subsequent definitive diagnoses based on pathological findings. The sensitivity and specificity for CE diagnosis were calculated. RESULTS: On CE findings, SCC showed the characteristics of absent and tortuous blood vessels, heterogeneous distribution, and increased nucleus/cytoplasm (N/C) ratio. Leukoplakia showed no atypical cells, abundant cornified layers, or cytoplasm without nuclei. Lesions were pathologically classified into three groups: 46 squamous cell carcinomas (SCC), 10 leukoplakias, and 10 other benign lesions (n=66). In 4 patients with SCC, malignancy was underestimated by CE findings. The overall diagnostic rate of the CE was 93.9% (62/66 patients). The sensitivity and specificity of SCC were 0.913 (42/46 patients) and 1.0 (20/20 patients), respectively. CONCLUSION: The usefulness of contact endoscopy (CE) as an in vivo real-time diagnostic instrument that can deliver results prior to pathological confirmation was suggested.

[Clinical investigation using a self-rating depression scale in subjects with psychosomatic taste disorders].

In recent years, the number of patients with psychologenesis taste disorders has increased. In this study, related psychological factors were examined in 258 patients (85 men, 173 women) using a self-rating depression scale (SDS). The results were as follows: 1) 189 patients reported normal psychological factors, 2) 173 patients reported neurotic sates, and 3) 40 patients reported positive correlations with a depressive sates, Most of the patients, self-reported results were not correlated with taste function tests. On the other hand, the patients with depression had reduced salivary secretion tests results. Only 50% of the patients with depression recovered their taste functions. These results suggest that the SDS test may be useful for diagnosing taste disorders and monitoring effects of treatment.

[Treatment outcome in patients with taste disturbance].

The importance of taste has been recently evaluated from the standpoint of quality of life, but few reports exist on the clinical status of taste disturbance. We classified taste disturbance by cause and studied the effect of treatment and recovery duration. Subjects were 321 patients with taste disturbance, i.e., 131 men and 190 women (mean age: 59.9 years). Electrogustometry (EGM) and filter paper disks (FPD) were used to assess taste function in all subjects. We also asked them all about the degree of symptoms using visual analog scale (VAS). Statistical analysis was done using the unpaired t-test, with p<0.05 considered significant. Patients were treated with zinc sulfate, ferrotherapy, herbal medicine, and minor tranquilizers. Causes of taste disturbance were classified into idiopathic, post-common-cold, drug-induced, psychogenic, constitutional, and iron deficiency. Idiopathic taste disturbance was the commonest cause (125 cases, 38.9%), followed by drug-induced (62 cases, 19.3%), and post common cold (38 cases, 11.8%). Drug induced and psychogenic taste disturbance have increased. Recovery from symptoms was 79/103 (76.7%) in idiopathic taste disturbance, 24/33 (72.7%) in post-common-cold, and 14/17 (82.4%) in iron deficiency. Recovery took 22.2 weeks. Recovery was 32/50 cases (62.4%) in drug induced, taking 48 weeks. For all causes, EGM and FPD results were not associated with the degree of symptoms. Both tests tended to show delayed improvement compared to symptoms. Cases taking more than 6 months from symptom onset to medical examination showed significantly lower improvement and longer recovery time than those taking 6 months on less (p = 0.04).

Taste function after section of chorda tympani nerve in middle ear surgery.

OBJECTIVE: To investigate prospectively the clinical manifestations and the functional recovery of taste after section of chorda tympani nerve (CTN) during middle ear surgery, the subjective and objective study on the patients was performed. METHODS: Thirty-five patients underwent surgery with unilateral (n=32) or bilateral (n=3) section of CTN between January 2000 and April 2002. The patients were asked about taste symptoms before surgery and 2 weeks and 2 years after surgery. The CTN function was also measured with electrogustometry (EGM) at the same time points. RESULTS: In unilateral section of CTN, 19/32 (59.4%) complained of taste disorder and 11/32 (34.4%) tongue numbness. Most of these taste symptoms disappeared within 2 years although the EGM threshold did not recover. 16/17 patients (94.1%) who used to cook everyday had little difficulty in flavoring dishes. In bilateral section of CTN, the patients had no problem of taste at 2 years after surgery, either. CONCLUSION: These findings help explain the potential complications to the patients before surgery, although the number of cases was small in this series.

[Clinical experiences of the medication to taste disturbance by serum trace deficiency, especially serum iron deficiency].

Serum zinc deficiency is known to be a major cause of taste disturbances, but the effects of serum iron deficiency on taste disturbances are not widely known. In the present study, we clinically investigated the relationship between taste disturbances and serum iron deficiency as well as the results of pharmacological therapy. The clinical and serological test results of 25 patients with serum iron deficiency (3 men and 22 women; mean age +/- SD, 56.1 +/- 16.5 years) were reviewed at the Department of Otolaryngology, Hospital of Hyogo College of Medicine. All of the patients had been seen at the hospital between January 1999 and February 2003. Electrogustometry (EGM) and the filter paper disc method (FPD) were used to measure taste function. The patients were treated with iron and zinc supplements. The age distribution of the patients peaked at the ages of 40 and 70 years. The ratio of males to females was 1:7. Based on the EGM results, 70% of the patients exhibited taste disturbances. The FPD results showed that the recognition threshold of sour tastes was slightly higher than that of the other tastes. No significant difference in the results of treatment was seen, regardless of the duration of the deficiency. These results suggest that treatment with iron and zinc medicine is useful for correcting taste disturbances caused by serum deficiencies of trace elements.