Pathophysiology and treatment of muscle tension dysphonia: a review of the current knowledge

Objective. Muscle tension dysphonia (MTD) is a clinical and diagnostic term describing a spectrum of disturbed vocal fold behavior caused by increased tension of the (para)laryngeal musculature. Recent knowledge introduced MTD as a bridge between functional and organic disorders. This review addresses the causal and contributing factors of MTD and evaluates the different treatment options. Methods. We searched MEDLINE (Pubmed, 1950-2009) and CENTRAL (The Cochrane Library, Issue 2,2009). Studies were included if they reviewed the classification of functional dysphonia or the pathophysiology of MTD. Etiology and pathophysiology of MTD and circumlaryngeal manual therapy (CMT) were obligatory based on reviews and prospective cohort studies because randomized controlled trials (RCTs) are nonexisting. Concerning the treatment options of voice therapy and vocal hygiene, selection was based on RCTs and systematic reviews. Results. Etiological factors can be categorized into three new subgroups: (1) psychological and/or personality factors, (2) vocal misuse and abuse, and (3) compensation for underlying disease. The effective treatment options for MTD are (1) indirect therapy: vocal hygiene and patient education; (2) direct therapy: voice therapy and CMT; (3) medical treatment; and (4) surgery for secondary organic lesions. Conclusions. MTD is the pathological condition in which an excessive tension of the (para)laryngeal musculature, caused by a diverse number of etiological factors, leads to a disturbed voice. Etiological factors range from psychological/personality disorders and vocal misuse/abuse to compensatory vocal habits in case of laryngopharyngeal reflux, upper airway infections, and organic lesions. MTD needs to be approached in a multidisciplinary setting where close cooperation between a laryngologist and a speech language pathologist is possible