Spasmodic dysphonia (SD) is characterized by involuntary laryngeal muscle spasms during vocalization. Most previous neuroimaging studies of SD measured brain activation during voice production and suggested that SD arises from abnormal sensorimotor integration involving the cortical and subcortical regions. However, these studies did not clarify whether this abnormal sensorimotor activation arises from some endogenous neural mechanism underlying SD or merely reflects neural activation produced by abnormal vocalization. To identify the specific neural correlates of SD, we compared neural activation in SD patients and healthy participants using a sound discrimination task that does not require overt speech production, thereby allowing us to eliminate any neural effects associated with abnormal vocalization. Eleven patients with adductor-type SD and 11 age- and gender-matched healthy participants underwent functional MRI. We found overactivation in the left sensorimotor cortex and the left thalamus in the SD patients, suggesting that voice perception activates different neural systems between SD patients and healthy subjects. For the SD patients, moreover, the magnitude of sensorimotor activation showed a significant positive correlation with symptom severity measured at voice handicap index-10, suggesting that signals from the sensorimotor cortex can be a new biomarker for assessing disease severity. The present findings suggested that the sensorimotor cortex and thalamus play a central role in the generation of abnormal phonation in SD.

The maculae flavae of the human vocal fold are thought to be involved in the metabolism of extracellular matrices essential for the viscoelasticity of the human vocal fold mucosa as a vibrating tissue, and they are considered an important structure in the growth, development and aging of the human vocal fold mucosa.
There is growing evidence to suggest that the cells in the maculae flavae are tissue stem cells of the human vocal fold mucosa and the maculae flavae are a candidate for a stem cell niche. The tissue stem cells in the maculae flavae of the human vocal fold seem to rely more on anaerobic glycolysis, especially by the pentose phosphate pathway, for energy supply in comparison with oxidative phosphorylation.
The tissue stem cells in the maculae flavae of the human adult vocal fold mucosa have heterogeneity and hierarchy in the stem cell system. The metabolisms of cells with heterogeneity seem to be different from each other. The metabolism of the tissue stem cells in the maculae flavae of the human vocal fold mucosa is likely to prevent toxic reactive oxygen species and to be favorable for maintaining the stemness and undifferentiated states of the tissue stem cells in the stem cell system.
Further investigations are needed regarding the stem cell system including the metabolic program of the tissue stem cells in the maculae flavae of the human vocal fold mucosa.

Patients with unilateral vocal fold paralysis (VFP) often have speech difficulties which cannot be thoroughly assessed by established voice evaluation methods, including subjective voice assessment, perceptual voice assessment, and aerodynamic and acoustic measures. Therefore, clinical voice evaluation incorporating speaking tasks and outcome indices is needed. This study aimed to examine differences in the speaking voice evaluation indices (breath frequency and single-breath speech length) before and after surgical interventions in these patients, and analyze the relationships with speaking voice evaluation and aerodynamic measures, including maximum phonation time (MPT) and mean flow rate (MFR). Eighteen patients with unilateral VFP (11 men and 7 women, aged 35 to 75 years) were asked to read the passage "North Wind and the Sun" aloud, and aerodynamic assessment of voice production was conducted before and after their surgeries. Acoustic analysis was performed for the first three sentences to obtain the breath frequency, and the mean and maximum single-breath speech length in mora. There were significant differences in all the indices between both evaluations. Breath frequency was less, and the mean and maximum single-breath speech lengths were longer in the post-surgery assessment. There were moderate correlations between breath frequency and aerodynamic measures, and between the mean single-breath speech length and MFR, in the pre-surgery assessment. In contrast, the speaking voice evaluation indices and aerodynamic measures did not show any correlation in the post-surgery assessment. These results suggest that an oral reading task with outcome indices could be useful for speaking voice evaluation for patients with unilateral VFP.

While conservative treatment is recommended as the first line of treatment for vocal fold lesions, including vocal fold polyps and nodules, the optimal therapeutic option in voice therapy to treat these lesions has not yet been established. In this study, we retrospectively assessed the therapeutic impact of voice therapy on vocal fold polyps to determine the ideal therapeutic option in voice therapy to achieve sufficient vocal outcome for the patients. Twenty-seven patients who underwent voice therapy as first-line treatment for vocal fold polyp between June 2017 and September 2020 were incorporated in this study. Either vocal hygiene instruction alone (VH group) or vocal training additional to vocal hygiene instruction (VT group) was performed in these patients. The therapeutic option was determined after discussion with each patient concerning the details of both therapies. No significant difference in polyp size change was observed between the groups. However, significantly better improvement in glottic closure was observed in the VT group compared with the VH group. Our study suggested that a combination of vocal hygiene instruction and vocal training could provide better vocal outcome than vocal hygiene instruction alone, among conservative therapeutic options for patients with vocal fold polyps.

In this study, we performed group training using musical instruments for patients wearing a cochlear implant (CI) and examined the effects on sound localization and speech discrimination. The subjects were selected at age 20 or over, had a speech discrimination score for monosyllables above 60% while wearing CI, and expressed a desire to participate in this training. The music training was carried out for 2 groups of 9 subjects each. A total of 12 group lessons, 60 minutes each, was held at a pace of 2 per month.
There were no significant differences in the scores for monosyllabic words, words, or sentences before and after the music training. There was also no significant difference between the average d-values of the localization test before and after training. Examination between groups with and without music experience also revealed no significant differences in the scores for monosyllabic words, words, or sentences or in the localization test results. Since some cases were effective, we believe the results indicate a need to construct detailed evaluation methods and more effective music training methods.

The aim of this study was to examine cases of bilateral simultaneous or sequential surgery with pediatric cochlear implantation. We compared causes of hearing loss, changes in threshold levels when wearing hearing aids (HA) and cochlear implant (CI), and differences in auditory behavior and vocalization/speech behavior between the two groups pre- and post-operatively. Among the bilateral CI cases under 6 years old performed at our hospital between April 2016 and August 2019, 5 cases underwent simultaneous surgery and 9 cases were performed sequentially. There were no significant differences between the two groups concerning preoperative threshold levels when wearing or not wearing HA, developmental indexes of KIDS, rates of execution of newborn hearing screening test and deafness genetic test, age at implantation, and postoperative threshold levels wearing CI. The results of the deafness genetic test revealed the causative genes for which cochlear implant is useful, which provided the basis for considering simultaneous or early sequential surgery. The scores of IT-MAIS and MUSS at 3 and 6 months after activation were significantly improved in both groups compared with before surgery. In this study there was no significant difference between the two groups, but we would like to continue comparing their progress going forward.

The effectiveness of using a multidimensional and comprehensive approach in the treatment of children who stutter has been reported, but most reports have focused on practices in hospitals and research institutions. There have been only a few case reports on children who stutter who have undergone treatment in special education classes, and there is a need to accumulate more findings. This report describes a case of a child with severe stuttering who was treated in a resource room using a multidimensional and comprehensive approach to address the symptoms of stuttering as well as cognitive, emotional, and environmental aspects. Following implementation, the child's severity of stuttering improved from severe to mild, communicative attitude tended to be more positive, and both the parents and the child became less anxious about stuttering. The progress demonstrated in this case suggests the following points when implementing a multidimensional and comprehensive treatment approach in special education classes: (1) fluency promotion and fluency shaping are effective in improving fluency in school-age children; (2) a cognitive- and behavior-focused approach to stuttering may contribute to anxiety reduction and cognitive change; and (3) correct knowledge of stuttering needs to be conveyed by making environmental adjustments at home and in the school setting.

Botulinum toxin A (Botox^®, BT) injection for patients with spasmodic dysphonia (SD) has been covered by national health insurance in Japan since 2018, and we have treated patients with SD using BT in our clinic. BT injection does not require complicated techniques and can be readily performed in clinics both technically and in terms of safety. The national insurance coverage of BT injection has greatly improved the treatment of stuttering or trembling voice and also patient satisfaction. However, a number of issues exist relating to continuity of the treatment, for example: diagnostic difficulties (including distinguishing SD from functional dysphonia) and cost challenges needing to be overcome.
In the present study, the effects of BT injection into the vocal cord to treat adductor SD in our clinic were statistically summarized. We also reported the technical procedures for BT injection and discussed some problems. BT injection was performed using a battery-powered compact type of electromyograph. Generally, the effectiveness of BT injection is considered to continue for three to four months and repetitive injections are required. However, four out of the 24 patients treated with BT injection in our clinic had no or slight recurrences and needed no additional injection. Therefore, the necessity of additional injections should be carefully considered. In addition, from an economic viewpoint the technical fee for ongoing BT injections should be covered by national health insurance to enable continuity of the treatment when necessary.