Diagnostic criteria for blepharospasm: A multicenter international study

Giovanni Defazio, Hyder A Jinnah, Alfredo Berardelli, Joel S Perlmutter, Gamze Kilic Berkmen, Brian D Berman, Joseph Jankovic, Tobias Bäumer, Cynthia Comella, Adam C Cotton, Tommaso Ercoli, Gina Ferrazzano, Susan Fox, Han-Joon Kim, Emile Sami Moukheiber, Sarah Pirio Richardson, Anne Weissbach, Laura J Wrigth, Mark Hallett

Research output: Contribution to journalArticlepeer-review

Abstract

BACKGROUND: There are no widely accepted criteria to aid the physician in diagnosing BSP.

OBJECTIVE: To validate recently proposed diagnostic criteria for blepharospasm in a larger and geographically diverse population and to develop a screening system for blepharospasm.

METHODS: Video-recordings from 211 blepharospasm patients and 166 healthy/disease controls were examined by 8 raters. Agreement for presence of orbicularis oculi spasms, sensory trick, and increased blinking was measured by k statistics. Inability to voluntarily suppress the spasms was asked by the examiner but not captured in the video. Patients/controls were also requested to fill a self-administered questionnaire addressing relevant blepharospasm clinical aspects. The diagnosis at each site was the gold standard for sensitivity/specificity.

RESULTS: All the study items yielded satisfactory inter/intra-observer agreement. Combination of items rather than each item alone reached satisfactory sensitivity/specificity. The combined algorithm started with recognition of spasms followed by sensory trick. In the absence of a sensory trick, including "increased blinking" or "inability to voluntarily suppress the spasms" or both items yielded 88-92% sensitivity and 79-83% specificity. No single question of the questionnaire yielded high sensitivity/specificity. Serial application of the questionnaire to our blepharospasm and control subjects and subsequent clinical examination of subjects screening positive by the validated diagnostic algorithms yielded 78-81% sensitivity and 83-91% specificity.

CONCLUSION: These results support the use of proposed diagnostic criteria in multi-ethnic, multi-center cohorts. We also propose a case-finding procedure to screen blepharospasm in a given population with less effort than would be required by examination of all subjects.

Original languageEnglish
Pages (from-to)109-114
Number of pages6
JournalParkinsonism and Related Disorders
Volume91
DOIs
Publication statusE-pub ahead of print - Sep 8 2021

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