Paradoxical use of frontalis muscle and the possible role of botulinum a toxin in permanent motor relearning.

Abstract

To report 7 patients with paradoxical use of the frontalis muscle despite postsurgical correction of ptosis with good postoperative eyelid position. Successful treatment with botulinum A toxin facilitated motor relearning and cessation of muscle contraction. Interventional case series. Seven patients, in 2 eye-plastic clinics, who underwent successful surgical correction of upper eyelid ptosis. Review of clinical history, clinical photographs, treatment, and follow-up. Frontalis muscle contraction and upper eyelid position. Patients underwent successful surgical correction of ptosis but continued using the frontalis muscle despite good eyelid position postoperatively. Frontalis contraction ceased spontaneously in 2 patients, but required botulinum A toxin injection in 5. The effects of a single treatment of botulinum A toxin lasted from 3 months to 2 years, longer than the expected effect of the toxin. Patients with long-standing eyelid ptosis may paradoxically continue utilizing the frontalis after successful surgical correction and despite good postoperative eyelid position. Cessation of frontalis contraction can be achieved with a single injection of botulinum A toxin. We hypothesize that chemodenervation, achieved with the toxin, may influence the central nervous system to relearn the set point for muscle contraction and may be associated with permanent motor relearning. Spontaneous resolution of muscle contraction can occur in the first months after surgery.