title: A novel mechanism for benign essential blepharospasm.
abstract: OBJECTIVE
  The purpose of this study is to test the hypothesis that the photophobia of benign essential blepharospasm (BEB) is caused by sympathetically maintained pain.
  
  
  METHODS
  Nineteen patients with photophobia and BEB were enrolled in an unblinded prospective treatment trial. The intervention was blockade of the superior sympathetic ganglion with local anesthetic. Outcome measures included the patient's subjective report of ocular surface dryness, foreign body sensation, and eyelid spasm. We also obtained video recordings of eyelid movements.
  
  
  RESULTS
  Of the 19 patients, 13 reported subjective improvement in BEB symptoms after cervical sympathetic blockade (CSB). Thirteen of 19 patients also had objective evidence of decreased light-induced eyelid spasm after CSB. Ocular surface disease was present in 18 of 19 patients.
  
  
  CONCLUSIONS
  These data support the hypothesis that in many patients with BEB there is a sympathetically maintained pain syndrome associated with external ocular disease. We speculate on a neurologic circuit that may explain these findings.
authors.affiliation: Division of Orbital and Ophthalmic Plastic Surgery, Jules Stein Eye Institute, University of California at Los Angeles, 90095-7006, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: McCann
authors.forename: M
authors.initials: M
authors.lastname: Gauthier
authors.forename: R
authors.initials: R
authors.lastname: Morschbacher
authors.forename: R A
authors.initials: RA
authors.lastname: Goldberg
authors.forename: R L
authors.initials: RL
authors.lastname: Anderson
authors.forename: P G
authors.initials: PG
authors.lastname: Fine
authors.forename: K B
authors.initials: KB
authors.lastname: Digre
mesh_terms: D000779:Anesthetics, Local / Q000008:administration & dosage; D001340:Autonomic Nerve Block; D001342:Autonomic Nervous System Diseases / Q000150:complications* / Q000503:physiopathology; D001764:Blepharospasm / Q000209:etiology* / Q000503:physiopathology; D005143:Eyelids / Q000294:innervation* / Q000503:physiopathology; D006801:Humans; D007267:Injections; D008012:Lidocaine / Q000008:administration & dosage; D010146:Pain / Q000150:complications / Q000503:physiopathology; D020795:Photophobia / Q000209:etiology / Q000503:physiopathology; D011446:Prospective Studies; D017783:Superior Cervical Ganglion / Q000187:drug effects
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine