Edrophonium Challenge Test for Blepharospasm

Shinichi Matsumoto,Hidetaka Koizumi,Masatoshi Takahashi,Ryuji Kaji,Nagahisa Murakami,Yuishin Izumi

doi:10.3389/fnins.2016.00226

Shinichi Matsumoto, Hidetaka Koizumi + Show 4 more

Open Access

https://doi.org/10.3389/fnins.2016.00226

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Abstract

Background: Blepharospasm is typically diagnosed by excluding any secondary diseases and neuropsychiatric disorders, as specific tests for blepharospasm are currently unavailable. Since anticholinergic agents are used to improve the symptoms of dystonia, we hypothesized that edrophonium chloride, an acetylcholinesterase inhibitor, may make the symptoms of dystonia more apparent. Therefore, we examined whether an edrophonium challenge test would be useful for diagnosing blepharospasm.Methods: We studied 10 patients with blepharospasm and 10 with hemifacial spasms (as disease controls). We administered edrophonium and saline in this double-blind study. Before and after the injection, we recorded the clinical signs using a video camera to assess the objective symptoms every 2 min. Ten minutes after the isotonic sodium chloride and edrophonium injections, the patients evaluated their subjective signs using a visual analog scale (VAS). The objective signs on the video recordings were scored by specialists who were blind to the treatment.Results: The subjective and objective signs of the patients with blepharospasm were amplified by edrophonium. In contrast, the signs in patients with hemifacial spasms were not changed by the edrophonium challenge test.Conclusions: The edrophonium challenge test may be used to diagnose blepharospasm. The study was registered with a ICMJE recognized registry, the UMIN-CTR, with the number UMIN000022557.

Highlights

Dystonia is a clinical syndrome characterized by sustained muscle contractions that cause twisting and repetitive movements or abnormal postures (Fahn et al, 1998)
Eyelid closure dysfunction in myasthenia gravis (MG) is related to abnormal functioning of the levator palpebrae superioris muscle due to deficient cholinergic transmission at Edrophonium Test for Blepharospasm the neuromuscular junction, while in blepharospasm, eyelid closure dysfunction is due to the strong involuntary contraction of the orbicularis oculi muscle
The visual analog scale (VAS) scores for the subjective signs and the modified VAS (mVAS) scores for the objective signs were significantly higher after edrophonium injection than they were after saline injection (Figure 1)

Summary

Introduction

Dystonia is a clinical syndrome characterized by sustained muscle contractions that cause twisting and repetitive movements or abnormal postures (Fahn et al, 1998). Blepharospasm, which presents with abnormal eyelid closure, is caused by dystonia of the eyelids. Blepharospasm is typically diagnosed by excluding any secondary diseases and neuropsychiatric disorders because of the unavailability of specific tests for blepharospasm. In a previously encountered case, we administered an edrophonium injection to a patient with abnormal eyelid closure and diplopia, which resulted in improvement of the diplopia, but amplification of the abnormal eyelid closure. Eyelid closure dysfunction in MG is related to abnormal functioning of the levator palpebrae superioris muscle due to deficient cholinergic transmission at Edrophonium Test for Blepharospasm the neuromuscular junction, while in blepharospasm, eyelid closure dysfunction is due to the strong involuntary contraction of the orbicularis oculi muscle. Blepharospasm is typically diagnosed by excluding any secondary diseases and neuropsychiatric disorders, as specific tests for blepharospasm are currently unavailable. We examined whether an edrophonium challenge test would be useful for diagnosing blepharospasm

Methods

Results

Conclusion