Blepharospasm: a case study comparison of trihexyphenidyl (Artane) versus EMG biofeedback

Blepharospasm is a chronic condition characterized by involuntary spasmodic closure of the eyelid(s). The present investigation empirically evaluated the relative efficacies of a current pharmacological and a psychological approach in the treatment of blepharospasm. An A-B-A-C-A single-case design was used to compare trihexyphenidyl [Artane] with EMG biofeedback. EMG activity in the frontalis muscle and number of eyeblinks were the dependent variables. The results indicated that Artane had no effect on either dependent measure and that biofeedback had a dramatic treatment effect on both dependent variables. Treatment gains were maintained at a 42-week follow-up. These results are discussed in light of the methodological considerations, the efficacy of psychological intervention, and the need for future research.