Botulinum Toxin Therapy: A Series of Clinical Studies on Patients with Spasmodic Dysphonia in Japan
Spasmodic dysphonia (SD) is a rare voice disorder caused by involuntary and intermittent spasms of the laryngeal muscles. Both diagnosis and treatment have been controversial. Therefore, a series of clinical studies has recently been conducted in Japan. A nationwide epidemiological survey revealed t...
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MDPI AG
2021-11-01
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| Series: | Toxins |
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| Online Access: | https://www.mdpi.com/2072-6651/13/12/840 |
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| author | Masamitsu Hyodo Kento Asano Asuka Nagao Kahori Hirose Maya Nakahira Saori Yanagida Noriko Nishizawa |
| author_facet | Masamitsu Hyodo Kento Asano Asuka Nagao Kahori Hirose Maya Nakahira Saori Yanagida Noriko Nishizawa |
| author_sort | Masamitsu Hyodo |
| collection | DOAJ |
| description | Spasmodic dysphonia (SD) is a rare voice disorder caused by involuntary and intermittent spasms of the laryngeal muscles. Both diagnosis and treatment have been controversial. Therefore, a series of clinical studies has recently been conducted in Japan. A nationwide epidemiological survey revealed that adductor SD predominated (90–95% of all cases; 3.5–7.0/100,000), principally among young women in their 20s and 30s. To facilitate early diagnosis, we created diagnostic criteria for SD and a severity grading system. The diagnostic criteria include the principal and accompanying symptoms, clinical findings during phonation, the treatment response, and the differential diagnoses. The severity grade is determined using a combination of subjective and objective assessments. Botulinum toxin (BT) injection is the treatment of choice; however, there have been few high-quality clinical studies and BT has been used off-label. We conducted a placebo-controlled, randomized, double-blinded clinical trial of BT therapy; this was effective and safe. BT treatment is now funded by the Japanese medical insurance scheme. Studies thus far have facilitated early diagnosis and appropriate therapy; they have fostered patient awareness of SD. |
| first_indexed | 2024-03-10T03:58:35Z |
| format | Article |
| id | doaj.art-fbaf45fb4d4e4ac0bbcd2adcb8d85004 |
| institution | Directory Open Access Journal |
| issn | 2072-6651 |
| language | English |
| last_indexed | 2024-03-10T03:58:35Z |
| publishDate | 2021-11-01 |
| publisher | MDPI AG |
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| series | Toxins |
| spelling | doaj.art-fbaf45fb4d4e4ac0bbcd2adcb8d850042023-11-23T10:50:17ZengMDPI AGToxins2072-66512021-11-01131284010.3390/toxins13120840Botulinum Toxin Therapy: A Series of Clinical Studies on Patients with Spasmodic Dysphonia in JapanMasamitsu Hyodo0Kento Asano1Asuka Nagao2Kahori Hirose3Maya Nakahira4Saori Yanagida5Noriko Nishizawa6Department of Otolaryngology-Head and Neck Surgery, Kochi Medical School, Nankoku 783-8505, JapanIntegrated Center for Advanced Medical Technologies, Kochi Medical School Hospital, Nankoku 783-8505, JapanDepartment of Otolaryngology-Head and Neck Surgery, Kochi Medical School, Nankoku 783-8505, JapanDepartment of Otolaryngology-Head and Neck Surgery, Kochi Medical School, Nankoku 783-8505, JapanRehabilitation Department, Kochi Medical School Hospital, Nankoku 783-8505, JapanDepartment of Communication Disorders, School of Rehabilitation, Health Sciences University of Hokkaido, Tobetsu 061-0293, JapanDepartment of Communication Disorders, School of Rehabilitation, Health Sciences University of Hokkaido, Tobetsu 061-0293, JapanSpasmodic dysphonia (SD) is a rare voice disorder caused by involuntary and intermittent spasms of the laryngeal muscles. Both diagnosis and treatment have been controversial. Therefore, a series of clinical studies has recently been conducted in Japan. A nationwide epidemiological survey revealed that adductor SD predominated (90–95% of all cases; 3.5–7.0/100,000), principally among young women in their 20s and 30s. To facilitate early diagnosis, we created diagnostic criteria for SD and a severity grading system. The diagnostic criteria include the principal and accompanying symptoms, clinical findings during phonation, the treatment response, and the differential diagnoses. The severity grade is determined using a combination of subjective and objective assessments. Botulinum toxin (BT) injection is the treatment of choice; however, there have been few high-quality clinical studies and BT has been used off-label. We conducted a placebo-controlled, randomized, double-blinded clinical trial of BT therapy; this was effective and safe. BT treatment is now funded by the Japanese medical insurance scheme. Studies thus far have facilitated early diagnosis and appropriate therapy; they have fostered patient awareness of SD.https://www.mdpi.com/2072-6651/13/12/840spasmodic dysphonianationwide surveydiagnostic criteriaseverity gradingplacebo-controlled double-blind clinical trial |
| spellingShingle | Masamitsu Hyodo Kento Asano Asuka Nagao Kahori Hirose Maya Nakahira Saori Yanagida Noriko Nishizawa Botulinum Toxin Therapy: A Series of Clinical Studies on Patients with Spasmodic Dysphonia in Japan Toxins spasmodic dysphonia nationwide survey diagnostic criteria severity grading placebo-controlled double-blind clinical trial |
| title | Botulinum Toxin Therapy: A Series of Clinical Studies on Patients with Spasmodic Dysphonia in Japan |
| title_full | Botulinum Toxin Therapy: A Series of Clinical Studies on Patients with Spasmodic Dysphonia in Japan |
| title_fullStr | Botulinum Toxin Therapy: A Series of Clinical Studies on Patients with Spasmodic Dysphonia in Japan |
| title_full_unstemmed | Botulinum Toxin Therapy: A Series of Clinical Studies on Patients with Spasmodic Dysphonia in Japan |
| title_short | Botulinum Toxin Therapy: A Series of Clinical Studies on Patients with Spasmodic Dysphonia in Japan |
| title_sort | botulinum toxin therapy a series of clinical studies on patients with spasmodic dysphonia in japan |
| topic | spasmodic dysphonia nationwide survey diagnostic criteria severity grading placebo-controlled double-blind clinical trial |
| url | https://www.mdpi.com/2072-6651/13/12/840 |
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