[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).

[The effect of zinc agent in 219 patients with zinc deficiency-inductive/ idiopathic taste disorder: a placebo controlled randomized study].

Diagnosis and treatment of taste disorders are challenging because the disorder can only be determined by the awareness of the patient. Hence, these disorders still require comprehensive evidence. We conducted a randomized, placebo-controlled double-blind study to investigate the effect of polaprezinc, a zinc-containing agent, in 219 patients with either zinc deficiency-inductive or an idiopathic taste, disorder. As a result, the zinc-treated arm experienced a statistically significant improvement against the placebo-treated arm in the perceptible threshold scores of the filter-paper disk method 8 weeks after the administration of the investigational drug. Moreover, the effect lasted for 4 weeks after discontinuation of the drug. However, the effective ratios based on the initial criteria were 55.6% in the treatment group and 43.2% in the placebo, where no statistical significance was recorded. Sex and degree of depression could be two of the potential factors to explain this discrepancy. Furthermore, the effect was not significant among male patients and patients with a high depression score based on the Self-rating Depression Scale (SDS) test. These results indicate that determining the symptom among such patients remains undisclosed. Whereas, in approximately 77%, or 168 patients with "normal" SDS scores and with completely impaired taste qualities, the ratio of effective cases reached 60.9% in the zinc-treated group, the ratio of the placebo-treated group reached 39.5%, resulting in a statistical significance. This may be partly because of a problem in the adaption of male subjects to the gustatory analyses, especially to the identification of saltiness and sourness. Care must also be taken regarding the depressive state of patients when diagnosing and treating taste disorders. Taste disorders caused by depression may not be cured by zinc supplementation due in part to the fact that the symptom is based on a mental issue, and due in part to the conservative responding bias generated by the depression itself, which may inhibit accurate and precise diagnosis of the disorder. In conclusion, administration of a zinc agent is effective for patients with taste disorders, provided selection of appropriate patients is performed, and that proper examination and evaluation are conducted. The present study also indicated that examining depressiveness based on the SDS scores and investigating disturbance of each taste quality using the filter-paper disk method are recommended for the diagnosis and determination of the treatment effect of a taste disorder.

Furosemide-loading vestibular evoked myogenic potential testing can suggest developing bilateral involvement of unilateral Meniere's disease.

CONCLUSIONS: Patients with positive results of furosemide-loading vestibular evoked myogenic potential (F-VEMP) testing in the unaffected ears of unilateral Meniere's disease have a high incidence of developing bilateral lesions. OBJECTIVE: To clarify the meaning of positive results of F-VEMP testing of the unaffected ear of patients with unilateral Meniere's disease. METHODS: Twenty-five patients with unilateral Meniere's disease were investigated in this study. The positive group consisted of 6 patients with positive results of F-VEMP testing in the contralateral ear and the negative group consisted of 19 patients with negative results. The incidence of contralateral involvement was compared in both groups by the Kaplan-Meier method. RESULTS: Contralateral involvement was seen in three cases (50%) in the positive group after 2, 12, and 26 months and in three cases (16%) in the negative group after 27, 56, and 78 months. The positive group had a higher incidence of contralateral involvement than the negative group (p = 0.0017, according to a log-rank test).

Vestibular evoked myogenic potentials of undiagnosed dizziness.

OBJECTIVE: Recording of vestibular evoked myogenic potentials (VEMP) can facilitate the evaluation of otolith function. The dizziness caused by otolith lesions is not completely understood. To clarify which symptoms of dizziness originate from the otolith organs, we examined the relationship between symptoms and VEMP results in patients with undiagnosed dizziness. METHODS: The subjects were 18 patients with undiagnosed dizziness aged less than 40 years who underwent VEMP examination. The VEMP results were evaluated using the interaural ratio of p13-n23 amplitude. RESULTS: Abnormal VEMP results were obtained in five of seven patients who experienced a sensation of falling (p=0.013), in none of the three patients who experienced a swaying sensation (p>0.05), and in one of eight patients who experienced a floating sensation (p>0.05). Five of six patients with abnormal VEMP results complained of disequilibrium lasting a few seconds. CONCLUSIONS: Dizziness with a sensation of falling lasting for a few seconds was related to abnormal VEMP results, suggesting that it resulted from saccular dysfunction. VEMP examination may be considered a useful modality in the diagnosis of dizziness of unknown origin.

Differential expression of capsaicin-, menthol-, and mustard oil-sensitive receptors in naive rat geniculate ganglion neurons.

The roles of capsaicin, menthol, and mustard oils and their receptors in geniculate ganglion (GG) neurons still remain to be elucidated. These receptors belong to the transient receptor potential (TRP) family. Capsaicin-, menthol-, and mustard oil-sensitive receptors are TRPV1, TRPM8, and TRPA1, respectively. The present study aimed to investigate the expression of TRPV1, TRPM8, and TRPA1 in naive rat GG neurons. Furthermore, we examined whether these TRP-expressing GG neurons are myelinated A-fiber or unmyelinated C-fiber neurons. Firstly, using reverse transcription-polymerase chain reaction, TRPV1 mRNA and TRPA1 mRNA were distinctly detected in the naive GG. TRPM8 mRNA was faintly detected. Secondly, using in situ hybridization, TRPV1 mRNA- or TRPA1 mRNA-labeled neurons (signal/noise ratio >or= 10) were observed in 15-20% of GG neurons. Few neurons were labeled by TRPM8 mRNA. Thirdly, neurofilament 200 (NF200) protein, a marker of mylinated A-fiber neurons, was detected in 57% of naive GG neurons. Coexpression of TRPV1 mRNA or TRPA1 mRNA with NF200 was detected in 10% of GG neurons. The present study confirmed the expression of the TRP receptors in the naive GG. The possible roles of TRP receptors in naive GG neurons in somatosensory or gustatory function were suggested.

[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).

Frequency dynamics shift of vestibular evoked myogenic potentials in patients with endolymphatic hydrops.

OBJECTIVE: To measure the frequency dynamics of the vestibular evoked myogenic potential in patients with endolymphatic hydrops. STUDY DESIGN: A prospective study. SETTING: A university hospital. SUBJECTS: The endolymphatic hydrops group consisted of 28 affected ears of patients with definite unilateral Ménière's disease and a control group of 36 ears of 20 healthy volunteers. INTERVENTIONS: Vestibular evoked myogenic potentials generated by tone bursts at 250, 500, 700, 1,000, 1,500, 2,000, and 4,000 Hz were measured in both groups. Vestibular evoked myogenic potentials were also measured after furosemide administration in six patients in the endolymphatic hydrops group. MAIN OUTCOME MEASURE: The frequency sensitivity of vestibular evoked myogenic potential, as evaluated by p13-n23 normalized amplitude. RESULTS: Peak amplitudes were noted at 500 Hz in the control group and at 1,000 Hz in the endolymphatic hydrops group. After furosemide loading, peak amplitude shifted to a lower frequency in four of six ears. CONCLUSION: The peak amplitude of vestibular evoked myogenic potentials in the endolymphatic hydrops group was at a higher frequency than in the control group. The frequency of the saccule (nu) should be proportional to radical(tau/sigma), where tau is the tension of membrane and sigma is its density. We advocate the hypothesis that the shift in frequency dynamics of vestibular evoked myogenic potential in patients with endolymphatic hydrops originates from the morphologic features of the saccule, analogous to an expanded balloon.

[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.