Blepharoclonus serves as a potential novel clinical marker in Parkinson disease
Presenter: Nestor Beltre, MD, Department of Neurology, University of Miami Miller School of Medicine, Miami, FL.
Blepharoclonus in Parkinson’s disease. Abstract 11-009. Presented April 23, 2023.
Blepharoclonus is a rare abnormal movement of the eyelids identified by brief, repetitive spasms of the lid on gentle eye closure. Spontaneous blinking in humans is mediated by the central dopaminergic activity and can be a useful clinical sign. The blink rate is decreased in diseases of altered dopaminergic activity, such as Parkinson disease, and increased in Huntington disease, Tourette syndrome, and Wilson disease.
To assess the prevalence of blepharoclonus in patients with idiopathic Parkinson disease, researchers at the University of Miami, in Miami, Florida, conducted a single-center cohort study in 75 patients. They noted the association of blepharoclonus with disease stage, tremor severity, and various nonmotor symptoms, and the prevalence of blepharoclonus in synucleinopathy versus nonsynucleinopathy-associated parkinsonism.
Synucleinopathies are a diverse group of neurodegenerative disorders that share a common pathologic lesion composed of aggregates of insoluble alpha-synuclein protein in selectively vulnerable populations of neurons and glia.
“In our clinical practice, we have observed that patients with idiopathic Parkinson disease often have blepharoclonus, but its prevalence is not well described in the literature,” said lead abstract author Nestor Beltre, MD, Department of Neurology, University of Miami Miller School of Medicine. “Understanding the relative frequencies of blepharoclonus in idiopathic Parkinson disease and atypical parkinsonism syndromes will shed light on the diagnostic utility of this clinical sign.”
In this study, the researchers prospectively enrolled 75 patients with idiopathic Parkinson disease, mean age 66 years and mean disease duration of 4.2 years. Diagnosis was based on Movement Disorders Society (MDS) criteria.
Blepharoclonus was considered present if eyelid fluttering was sustained for more than 5 seconds after gentle eye closure. For each patient, the researchers asked selected questions from the MDS-UPDRS (Unified Parkinson’s Disease Rating Scale) part 2, REM (rapid eye movement) Sleep Behavior Disorder Questionnaire, MDS-UPDRS part 3 tremor assessments, and recorded the presence or absence of dyskinesia. Each patient’s eyelid flutter was videotaped.
Of the 75 patients, 63 (84%) had blepharoclonus. Previously, the researchers reported an 85% prevalence of blepharoclonus in smaller study of 20 patients with Parkinson disease. Significant associations were detected between higher tremor scores and the presence of REM-sleep behavior disorder with blepharoclonus. Blepharoclonus was present in 3 of 5 patients with synucleinopathy; it was not present in any patients with nonsynucleinopathy-associated Parkinson disease.
“Blepharoclonus was highly prevalent in our cohort,” Beltre said. “This suggests its possible utility as an additional clinical marker for Parkinson disease. Its presence, perhaps, may suggest a synucleinopathy rather than a tauopathy.”
He added, “We are actively enrolling atypical parkinsonism patients, including drug-induced parkinsonism, as a control group to assess for differential preference compared to idiopathic Parkinson disease.”
To further investigate the utility of this finding as a prodromal diagnostic marker, its prevalence could be assessed in patients with idiopathic REM sleep behavior disorder or among genetic cohorts of presymptomatic leucine-rich repeat kinase 2 or glucocerebrosidase patients, he said.
References
Behrman S, Scott DF. Blepharoclonus provoked by voluntary eye closure. Mov Disord 1988; 3(4):326-328. doi:10.1002/mds.870030407.
Beltre N, Feldman M, Marmol S, et al. Blepharoclonus as a potential novel clinical marker in Parkinson’s disease. Presented at the 75th Annual Meeting of the American Academy of Neurology, April 23, 2023. https://www.aan.com/MSA/Public/Events/AbstractDetails/54852
Lang AE, Jankovic J. Diagnosis and assessment of Parkinson disease and other movement disorders. In: Daroff RB, Mazziotta JC, Pomeroy SL, eds. Bradley's Neurology in Clinical Practice. 7th ed. London, England: Elsevier; 2016:310-333.
Margolesky J, Fleming N, Shpiner DS, et al. Blepharoclonus in Parkinson’s Disease: a prevalent and meaningful finding? Neurology 2020; 94(15 Suppl):2174.
Postuma RB, Berg D, Stern M, et al. MDS clinical diagnostic criteria for Parkinson's disease. Mov Disord 2015 Oct;30(12):1591-1601. doi:10.1002/mds.26424.
Disclosures
Nestor Beltre: Nothing to disclose.