A vocal fold sulcus is a ridge or furrow that runs the entire length of the medial (middle) surface of the membranous portion of the vocal fold. The sulcus often causes the vocal fold edge to appear bowed. Sulci usually occur bilaterally (both sides), though a unilateral (one side) sulcus can occur. When a sulcus is present, the stiffness of the vibrating cover is significantly increased. There is no clear cause for sulcus vocalis. However, one proposed theory is that vocal fold sulci develop following abnormal embryologic maturation of the vocal fold cover, resulting in a furrowed appearance of the membranous vocal fold edge. Also, apparent acquired onset of sulcus vocalis is also possible, especially following laser surgery, due to aging changes, and vocal fold paralysis.
Voice quality that results from a vocal fold sulcus may be mild to severely dysphonic depending on the stiffness of the fold and the size of the glottal gap caused by the sulcus. Treatment attempts involving surgical techniques for removing the sulcus have been attempted with mixed results. Direct voice therapy focused on increased vocal efficiency without excessive strain has yielded voice improvement for some patients, but no characteristic treatment of choice has emerged for this pathology.