• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.14 no.1
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• pp.54-56
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• 2003

Spasmodic dysphonia is a task-specific dystonia affecting the laryngeal muscles, resulting forced, strained voice. The pathophysiologic mechanism is not fully understood. We experienced a patient with epilepsy developed transient spasmodic dysphonia during valproic acid monotherapy. The spasmodic dysphonia resolved with dose reduction of valproic acid. Change of neurotransmitters, such as GABA in basal ganglia or blockade of sodium channel is possible mechanism in our case of drug-related spasmodic dysphonia.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.11 no.1
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• pp.98-103
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• 2000

Background and Objectives : The etiology and pathophysiology of spasmodic dysphonia is yet unknown. This study was performed to determine if any laryngeal aerodynamic parameter distinguish the voice of patient diagnosed as having adductor spasmodic dysphonia from individuals with normal voice production and to investigate the pathophysiology of spasmodic dysphonia. Materials and Methods : fifteen women diagnosed as having adductor spasmodic dysphonia and fifteen normal control women participitated in this study Maximum phonation time, mean air flow rate, subglottic pressure, vocal efficiency, Vfo, NHR, VTI, FTRI, ATRI, Jitter percent, Shimmer percent were obtained from the participants using 'MDVP(multi-dimensional voice program)' of CSL(Computerized Speech lab, Kay Elemetrics, Co., Model No. 4300), and 'maximum sustained phonation' and 'IPIPI test' of AP II(Aerophone II, Kay Elemetrics, Co., Model 6800). Results : T-test statistical analysis revealed statistically different values for vocal efficiency, Vfo, NHR, MPT, litter percent, Shimmer percent between the spasmodic dysphonia group and the control group. Conclusions : Spasmodic dysphonia affects the ability of the laryngeal mechanism to function effectively. Results from our study demonstrate that certain aerodynamic and acoustic parameters distinguish adductor spasmodic dysphonia from normal voice.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.63-70
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• 2013

The purpose of this study is to show the aerodynamic characteristics and differences in muscle tension dysphonia and adductor spasmodic dysphonia to predict factors which will provide additional information while preparing for the objective examination standard to distinguish the two dysphonias. Forty-eight individuals diagnosed with muscle tension dysphonia and adductor spasmodic dysphonia participated in this study. PAS was used in order to find the aerodynamic characteristics for the two dysphonias. The outcomes of this study show that the airflow variation and glottal resistance of the two groups showed noticeable differences. This study concludes that the aerodynamic characteristics may be used as additional information on diverse evaluations to classify muscle tension dysphonia and adductor spasmodic dysphonia.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.23 no.2
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• pp.99-103
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• 2012

Spasmodic dysphonia is a chronic, focal, movement-induced, action-specific dystonia of the laryngeal musculature during speech. It can have a profound effect on quality of life, severely limiting people's communication, especially via telephone and in noisy backgrounds. Spasmodic dysphonia (SD) is usually of the adductor type characterized by glottic contractions causing tightness and voice breaks with forced-strangled voice, but it may also be abductor type or, much less commonly, mixed. Treatment options for adductor spasmodic dysphonia (ADSD) include voice therapy, surgical procedures, and botulinum toxin injections (Botox). The use of Botox injected into the laryngeal muscles remains the "gold standard" treatment for reducing the vocal symptoms of ADSD and Botox induces a temporary paresis of the laryngeal muscles and provides short-term relief of symptoms. Repeated injections of the laryngeal muscles, generally every 3-4 months, are required for continuous relief of symptoms. Improvement in vocal function has been reported after use of Botox injections, though a completely normal voice is rarely achieved. In this hospital, 1,030 patients have been enrolled for Botox injection therapy so far (May, 2012). In this review article, I'd like to present my personal experience of management of spasmodic dysphonia mainly by Botox injection.

• Speech Sciences
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• v.3
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• pp.5-17
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• 1998

Botulinum toxin, a neurotoxin derived from Clostridia Botulinum, has been injected into the target muscle(s) for the treatment of several kinds of voice and speech disorders at the Voice Clinic, Yonsei Institute of Logopedics and Phoniatrics since December 1995. Criteria for the diagnosis and method of injection for spasmodic dysphonia, mutational dysphonia, muscle tension dysphonia, dysphonia after total laryngectomy, and stuttering were summarized. Among 144 patients with adductor type spasmodic dysphonia, who were injected one time to maximum 8 times during the 27 months, 90% were recognized as having better than slight improvement. Even though the injected cases were small, not only the abductor type spasmodic dysphonia, but also the intractable mutational dysphonia or muscle tension dysphonia resistant to voice therapy revealed that botulinum toxin injection would be another options for treatment. Patients who cannot phonate after total laryngectomy and some forms of adulthood stutterers can also be candidates for the injection of botulinum toxin.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.21 no.1
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• pp.57-60
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• 2010

Spasmodic dysphonia is a focal dystonia of the larynx and breathy voice is a typical sign of abductor spasmodic dysphonia. A group of patients with abductor spasmodic dysphonia have a number of acoustic characteristics including abnormal fundamental frequency fluctuations and abnormally long word duration. We report a abductor spasmodic dysphonia case have enlongated voice onset time voiceless consonants and breathy voice in wide band spectrogram. The patient have the acoustic characteristics only in telephone speaking at work time. We treated the patient with anticholinergic and anticonvulsant drug and supplementary voice therapy. The breathy voice and enlongated VOT were disappeared after those treatment.

• Proceedings of the KSPS conference
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• 2007.05a
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• pp.143-145
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• 2007

Muscle groups that are located in and around the vocal tract can produce audible changes in frequency and/or intensity of the voice. Vocal vibrato is a characteristic feature in the singing of performers trained in the western classical tradition and vibrato is generally considered to result from modulation in frequency amplitude and timbre. Vocal tremor is also characterized by periodic fluctuations in the voice frequency or intensity and vocal tremor is symptom of a neurological disease as Spasmodic dysphonia , Parkinson's disease. Vocal vibrato and Vocal tremor may have many of the same origins and mechanisms in the voice production systems. The purpose of this study is to find acostic character of Korean traditional song Pansori singer's vibrato and Spasmodic dysphonia patient's vocal tremor. twelve Pansori singers and seven Spasmodic dysponia patients participated to this study. Power spectrum and Real time Spectrogram are used to analyze the acoustic characteristics of Pansori singing and Spasmodic dysphonia patient's voice The results are as follows; First, vowel formant differences between Pansori singing and Spasmodic dysphonia patient's voice are higher F1, F3. Second, The vibrato rate show differences between Pansori singing and Spasmodic dysphonia patients;$4^{\sim}6/sec$ and $5{\sim}6/sec$ Vibrato rate of pitch is 5.7 Hz ${\sim}$ 42.4 Hz for Pansori singing , 3.8 Hz ${\sim}$ 27.9 Hz for Spasmodic dysphonia patients ;Vibrato rate of intensity range is 0.07 dB ${\sim}$ 8.26 dB for Pansori singing and 0.07 dB ${\sim}$ 4.81 dB for Spasmodic dysphonia patients

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.28 no.2
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• pp.71-78
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• 2017

Voice disorder is classified into three categories, structural, neurogenic and functional dysphonia. Neurogenic dysphonia refers to a disruption in the nerves controlling the larynx. Common examples of this include complete or partial vocal cord paralysis, spasmodic dysphonia. Also it occurs as part of an underlying neurologic condition such as Parkinson's disease, myasthenia gravis, Lou Gehrig's disease or disorder of the central nervous system that causes involuntary movement of the vocal folds during voice production. Functional dysphonia is a voice disorder in the absence of structual or neurogenic laryngeal characteristics. A near consensus exist that Muscle tension dysphonia (MTD) is functional voice disorder wherein hyperfunctional laryngeal muscle activity whereas Spasmodic dysphonia (SD) is neurogenic, action-induced focal laryngeal dystonia including several subtype. Both Adductor type spasmodic dysphonia (AdSD) and MTD may be associated with excessive supraglottic contraction and compensation, resulting in a strained voice quality with spastic voice breaks. It makes these two disorders extremely difficult to differentiate based on clinical interpretation alone. Because treatment for AdSD and MTD are quite different, correct diagnosis is important. Clinician should be aware of the specific vocal characteristics of each disease to improve therapeutic outcome.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.8 no.1
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• pp.54-58
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• 1997

Spasmodic dysphonia is an uncommon and poorly understood disorder of motor control of laryngeal speech. We analysed 88 patients with spasmodic dysphonia, using chart review. These patients had historical information evaluated for age of onset(mean 39.2 years), duration of symptoms(mean 8.8 years), sex(4.2 : 1 female to male) family history(positive in 16.7%), and primary(84.8%) and secondary(15.2%) etiology : neurological evaluation for other dystonic involvement(40.7%). Eighty-three patients(94.3%) had adductor type of spasmodic dysphonia and 4 patients were abductor type and 1 patient was mixed type. All patients had normal thyroid and parathyroid functions and among 46cases, 8 patients had abnormal brain MRI finding. seventeen patients were evaluated by auditory brainstem response parameters. four out of the 17 patiemts had prolonged wave Ⅰ-Ⅴ interpeak latency.

• Speech Sciences
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• v.9 no.4
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• pp.39-47
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• 2002

The purpose of this study was to investigate the effects of Seo Dongil's voice technique on voice quality in patient with adductor spasmodic dysphonia. One patient participated in the study. The subject was assessed acoustically (Ave Fo, Ave Int, percent speech time, percent silence time, percent voice time, percent voiceless time) and perceptually (GRBAS scales) in the first and last session. Dr. Speech (version 4.0, Tiger-DRS) was used to compare acoustic parameters of pre-and post-treatment. Seo Dongil's voice technique consisted of relaxation, breathing exercise and phonation exercise. The results were as follows: First, Seo Dongil's voice technique tented to be effective on decreasing voice break and voice stoppage in patient with adductor spasmodic dysphonia. Second, GRBAS scales showed that Seo Dongil's voice technique was effective on improving voice quality of patient with adductor spasmodic dysphonia.