title: Development and validation of a clinical guideline for diagnosing blepharospasm.
abstract: OBJECTIVE
  To design and validate a clinical diagnostic guideline for aiding physicians in confirming or refuting suspected blepharospasm.
  
  
  METHODS
  The guideline was developed and validated in a 3-step procedure: 1) identification of clinical items related to the phenomenology of blepharospasm, 2) assessment of the relevance of each item to the diagnosis of blepharospasm, and 3) evaluation of the reliability and diagnostic sensitivity/specificity of the selected clinical items.
  
  
  RESULTS
  Of 19 clinical items initially identified, 7 were admitted by content validity analysis to further assessment. Both neurologists and ophthalmologists achieved satisfactory interobserver agreement for all 7 items, including "involuntary eyelid narrowing/closure due to orbicularis oculi spasms," "bilateral spasms," "synchronous spasms," "stereotyped spasm pattern," "sensory trick," "inability to voluntarily suppress the spasms," and "blink count at rest." Each selected item yielded unsatisfactory accuracy in discriminating patients with blepharospasm from healthy subjects and patients with other eyelid disturbances. Combining the selected items, however, improved diagnostic sensitivity/specificity. The best combination, yielding 93% sensitivity and 90% specificity, was an algorithm starting with the item "stereotyped, bilateral, and synchronous orbicularis oculi spasms inducing eyelid narrowing/closure" and followed by recognition of "sensory trick" or, alternatively, "increased blinking."
  
  
  CONCLUSIONS
  This study provides an accurate and valid clinical guideline for diagnosing blepharospasm. Use of this guideline would make it easier for providers to recognize dystonia in clinical and research settings.
authors.affiliation: Department of Basic Medical Sciences, Neurosciences and Sense Organs, Aldo Moro University of Bari, Italy. gdefazio@neurol.uniba.it
authors.forename: Giovanni
authors.initials: G
authors.lastname: Defazio
authors.forename: Mark
authors.initials: M
authors.lastname: Hallett
authors.forename: Hyder A
authors.initials: HA
authors.lastname: Jinnah
authors.forename: Alfredo
authors.initials: A
authors.lastname: Berardelli
mesh_terms: D000368:Aged; D001764:Blepharospasm / Q000175:diagnosis*; D001767:Blinking; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010808:Physical Examination; D017410:Practice Guidelines as Topic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity