Diagnostic criteria for blepharospasm: A multicenter international study

• Published in: Parkinsonism & related disorders Vol. 91; pp. 109 - 114
• Main Authors: Defazio, Giovanni, Jinnah, Hyder A., Berardelli, Alfredo, Perlmutter, Joel S., Berkmen, Gamze Kilic, Berman, Brian D., Jankovic, Joseph, Bäumer, Tobias, Comella, Cynthia, Cotton, Adam C., Ercoli, Tommaso, Ferrazzano, Gina, Fox, Susan, Kim, Han-Joon, Moukheiber, Emile Sami, Richardson, Sarah Pirio, Weissbach, Anne, Wrigth, Laura J., Hallett, Mark
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.10.2021
• Subjects: Blepharospasm; Blepharospasm - diagnosis; Blinking; Case-Control Studies; Diagnosis; Dystonia; Female; Humans; Male; Middle Aged; Physical Examination - standards; Sensitivity and Specificity; Symptom Assessment - methods; Symptom Assessment - standards; Blepharospasm; Dystonia; Diagnosis
• ISSN: 1353-8020; 1873-5126; 1873-5126
• DOI: 10.1016/j.parkreldis.2021.09.004

There are no widely accepted criteria to aid the physician in diagnosing BSP. To validate recently proposed diagnostic criteria for blepharospasm in a larger and geographically diverse population and to develop a screening system for blepharospasm. 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. 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. 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. •To date there are no widely accepted criteria to diagnose BSP.•This study supports the use of proposed and validated diagnostic criteria.•A case-finding procedure is proposed to screen BSP in a given population.