Following speech assessment, the otolaryngologist conducts a flexible transnasal laryngoscopy to view the vocal folds and activity of the muscles controlling them in order to eliminate other possible causes of the voice disorder. In spasmodic dysphonia, producing long vowels or speaking sentences results in muscle spasms which are not observed during other vocal activities such as coughing, breathing, or whispering. To evaluate the individual for any other neurological problems, this examination is followed up with an assessment by the neurologist. Voice quality symbol
The voice quality symbol for spasmodic dysphonia is ꟿ. Differential diagnosis
Because spasmodic dysphonia shares many characteristics with other voice disorders, misdiagnosis frequently occurs. A common misdiagnosis is muscle tension dysphonia, a functional voice disorder which results from use of the voice, rather than a structural abnormality. Some parameters can help guide the clinician towards a decision. In muscle tension dysphonia, the vocal folds are typically hyperadducted in constant way, not in a spasmodic way. Additionally, the voice difficulties found in spasmodic dysphonia can be task specific, as opposed to those found in muscle tension dysphonia. Being able to differentiate between muscle tension dysphonia and spasmodic dysphonia is important because muscle tension dysphonia typically responds well to behavioural voice treatment but spasmodic dysphonia does not. This is crucial to avoid providing inappropriate treatment, but in some cases a trial of behavioural voice treatment can also be helpful to establish a differential diagnosis.Spasmodic dysphonia can also be misdiagnosed as voice tremor.
Voice therapy
Voice therapy appears to be ineffective in cases of true spasmodic dysphonia. However, as it is difficult to distinguish between spasmodic dysphonia and functional dysphonias, and misdiagnosis is relatively common, trial of voice therapy is often recommended before more invasive procedures are tried. Some also state that it is useful for mild symptoms and as an add-on to botox therapy and others report success in more severe cases. Laryngeal manual therapy, which is massaging of the neck and cervical structures, also shows positive results for intervention of functional dysphonia. Surgery
If other measures are not effective, surgery may be considered; however, evidence to support surgery as a treatment for SD is limited. Treatment outcomes are generally positive, though more research is required to determine its effectiveness. Post-surgery voices can be imperfect and about 15% of people have significant difficulties. If symptoms do recur, this typically happens in the first 12 months. As of 2011, surgery was rarely used as a treatment approach for SD. Surgical approaches include recurrent laryngeal nerve resection, selective laryngeal adductor denervation-reinnervation (SLAD-R), thyroplasty, thyroarytenoid myectomy, and laryngeal nerve crush. Recurrent laryngeal nerve resection involves removing a section of the recurrent laryngeal nerve. Recurrent laryngeal nerve avulsion is a more drastic removal of sections of the nerve, and has positive outcomes of 80% at three years. SLAD-R is effective specifically for adductor spasmodic dysphonia, for which it has shown good outcomes in about 80% of people at 8 years. Thyroplasty changes the position or length of the vocal folds.