A benign neurological voice disorder caused by laryngeal [intlink id=”148″ type=”post”]dystonia[/intlink]. Typically, during running speech, the voice is interrupted by sudden choking off of the voice, and there may be an underlying more continuous “tight” sound to the voice as well. Also called strain-strangle phonation. AD-SD comprises about 90% of cases of [intlink id=”512″ type=”post”]spasmodic dysphonia[/intlink]. Also exists in the less common [intlink id=”575″ type=”post”]tonic variant spasmodic dysphonia[/intlink].